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Plant Breeding and Seed Science 2012 67 T. Ayalneh, T. Letta, M. Abinasa Assessment of stability, adaptability and yield performance of bread wheat (Triticum aestivum l.) cultivars in south estern Ethiopia
The success of crop improvement and production activities can be enhanced with scientific information generated form genotype-environment interactions. GEI reduces the association between phenotype and genotype which result in relative ranking and stability differences of genotypes across environments. This study were conducted with the objective to identify stable, and adaptable bread wheat genotypes under various environments. Eighteen genotypes were tested across nine environments for two years on randomized block design of three replication. Plot size of 1.2 m × 2.5 m and 20cm spacing between rows were used. All recommended agronomic practices and managements were applied uniformly. Data were collected on plot basis and converted to ton ha-1. and analyzed with appropriate statistical software for stability parameters. Combined analysis over nine environments showed, variety Tuse (HAR-1407) ranked first in mean yield(3.11ton × ha-1), and K-6295-4A ranked second (3.01 ton × ha-1) and Dashen came third(2.98 ton ha-1). Analysis of AMMI model showed that the first principal component, PCA 1 explained 53.72% of the interaction sum of squares while the second principal component, PCA 2 explained 17.61% interaction sum of squares. Ecovalence(Wi) analysis showed that G2 (Sofumar(HAR-1889)), G4 (Kubsa(HAR-1685)), G5 (Tura(HAR-1407)), G7 (Galema (HAR-604)), G12 (Wabe (HAR-710)), almost equally the lowest ecovalence that evidenced less fluctuation across environment and found to be stable.
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Plant Breeding and Seed Science 2012 67 Ayda Hosseinzadeh-Mahootchi, Kazem Ghassemi-Golezani The impact of seed priming and aging on physiological performance of chickpea under different irrigation treatments
A sub-sample of chickpea (Cicer arietinum L. cv.ILC482) seeds was kept as control and two other sub-samples were aged at 40 °C for 3 and 5 days. Consequently, three seed lots with different levels of vigor were provided. These seed lots were soaked in distilled water at 15°C for 12 and 18 hours and then dried back to initial moisture content at a room temperature of 20-22°C. Then seeds were sown in the field as split plot factorial based on RCB design. Hydro-priming improved leaf chlorophyll content index of plants from different seed lots. Hydro-priming also enhanced stomatal conductance of plants from all seed lots under all irrigation levels, but this advantage for plants from low vigor seed lots particularly under limited irrigations was higher than that for other treatments. Plants from high vigor seed lot under different irrigation treatments had higher relative water content, compared with those from low vigor seed lots. Hydro-priming improved relative water content, membrane stability and grain yield of chickpea plants from different seed lots under various irrigation treatments. It was concluded that hydro-priming to some extent can repair aged seeds and improve their performance under different irrigation treatments.
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Plant Breeding and Seed Science 2012 67 Kazem Ghassemi-Golezani, Afsaneh Chadordooz-Jeddi, Saeid Zehtab-Salmasi, Shahin Oustan Influence of seed size and aging on seedling growth and field establishment of lentil (Lens culinaris Medik)
A sub-sample of lentil (Lens culinaris Medik. cv. Kimia) seeds was kept as bulk (S1) and the other seeds were separated by a sieve with four millimeters diameter. Consequently, three seed lots including bulk (S1), large (S2) and small (S3) seeds were obtained. Seeds of each size were divided into three sub-samples. A sub-sample was kept as control or high vigor seed lot (A1). The other two sub-samples with about 20% moisture content were artificially aged at 40°C for 2 and 4 days (A2 and A3, respectively). These seeds were evaluated in laboratory and field during 2011 and 2012 as factorial experiments on the bases of RCB design. The lowest mean germination and emergence times and the highest germination percentage, seedling dry weight and emergence percentage were recorded for high vigor seed lot. Large seeds produced the largest seedlings in comparison with bulk and small seeds. Although, seedling dry weight was reduced with increasing seed aging, the lowest reduction was recorded for seedlings from large seeds. The most deteriorated large seeds germinated earlier than those of bulk and small seeds. Early germination of the most deteriorated large seeds resulted in rapid emergence of seedlings in the field. This is also reflected in the highest positive correlation of mean germination time with mean emergence time. It was concluded that some deleterious effects of seed aging can be reduced by increasing seed size.
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Plant Breeding and Seed Science 2012 67 Kazem Ghassemi-Golezani, Saeid Ghassemi Effects of water supply on seed development and quality of chickpea cultivars
A split plot experiment (using RCB design) with three replications was conducted in 2012 and seed physiological quality of three chickpea (Cicer arietinum L.) cultivars (Azad, Arman and Jame) was evaluated at seven stages under well and limited irrigation conditions. Maximum seed weight (mass maturity) was achieved at 40-45 days after flowering. However, maximum seed quality was obtained 7 to 10 days after mass maturity, depending on irrigation intervals and cultivars. At earlier harvests, because of immaturity, and at later harvests, due to ageing, seed quality was low. Seed filling rate and maximum seed weight of chickpea decreased with decreasing water supply, but water deficit had no significant effects on seed quality as measured by germination percentage, germination rate and seedling dry weight. Significant differences in seedling dry weight among chickpea cultivars were attributed to significant variation in seed weight affected by genetic constitution.
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Plant Breeding and Seed Science 2012 67 Naser Sabaghnia, Rahmatollah Karimizadeh, Mohtasham Mohammadi Using additive main effect and multiplicative interaction model for exploration of yield stability in some lentil (Lens culinaris Medik.) genotypes
The additive main effect and multiplicative interaction (AMMI) analysis has been indicated to be effective in interpreting complex genotype by environment (GE) interactions of lentil (Lens culinaris Medik.) multi-environmental trials. Eighteen improved lentil genotypes were grown in 12 semiarid environments in Iran from 2007 to 2009. Complex GE interactions are difficult to understand with ordinary analysis of variance (ANOVA) or conventional stability methods. Combined analysis of variance indicated the genotype by location interaction (GL) and three way interactions (GYL) were highly significant. FGH1 and FGH2 tests indicated the five significant components; FRatio showed three significant components and F-Gollob detected seven significant components. The RMSPD (root mean square predicted difference) values of validation procedure indicated seven significant components. Using five components in AMMI stability parameters (EVFI, SIPCFI, AMGEFI and DFI) indicated that genotypes G5 and G6 were the most stable genotypes while considering three components in of AMMI stability parameters (EVFII, SIPCFII, AMGEFII and DFII) showed that genotypes G8 and G18 were the most stable genotypes. Also genotypes G2, G5 and G18 were the most stable genotypes according to AMMI stability parameters which calculated from seven components (EVFIII, SIPCFIII, AMGEFIII and DFIII). Among these stable genotypes, only genotypes G2 (1365.63 kg × ha-1), G11 (1374.13 kg × ha-1) and G12 (1334.73 kg × ha-1) had high mean yield and so could be regarded as the most favorable genotype. These genotypes are therefore recommended for release as commercial cultivars.
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Plant Breeding and Seed Science 2012 67 Valiollah Rameeh Genetic analysis of plant height, yield components and seed yield in rapeseed (Brassica napus L.) cultivars
Half F2 diallel crosses of spring rapeseed (Brassica napus L.) varieties along with their parents were evaluated for plant height, first siliqua height, siliquae on main axis, siliquae per plant, 1000-seed weight and seed yield. The Analysis of variance based on Cockerham’s method revealed significant mean squares of general combining ability (GCA), specific combining ability (SCA) for all the traits indicating that both additive and non-additive genetic effects were involved in controlling these traits. Parent vs crosses mean square which is indicating average heterosis was significant for all the traits. In Hayman’s method the regression lines estimated for all the traits except plant height cut the Wr axis below the origin in the negative zone, suggesting the overdominance type of gene action for these traits except plant height. Based on the array points on the regression lines, 19H had maximum dominant genes for siliquae on main axis, siliquae per plant 1000-seed weight and seed yield, being closest to the origin, while Option500 possessed recessive genes for first siliqua height, siliquae per plant and 1000-seed weight, as evidenced by its distant position from the origin. Due to low narrow-sense heritability estimates for most of the traits, selection for improving these traits should be carried out in delayed segregating generations.
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Plant Breeding and Seed Science 2012 67 M.A .Adebisi, O.A. Esuruoso, J.A .Adetumbi, A.M. Abdul-Rafiu, T.O. Kehinde, O.O. Ajani, O. Agboola Shelf life of kenaf (Hibiscus cannabinus L.) seed stored under humid tropical conditions
Successful crop production depends initially on the availability of high-quality seed. Seed viability and vigour of four kenaf varieties during storage were investigated. Seeds of each variety were packed inside thick polythene bags and kept in Seed Stores under ambient conditions in two storage locations (Federal University of Agriculture, Abeokuta (FUNAAB) (29.8°C, 59.10 RH%) and Institute of Agricultural Research and Training, Ibadan (27.5°C, 64.68 RH%) for 240 days (8 months). Seeds were sampled during storage at 0, 60, 120, 180 and 240 days and tested for seed viability and seedling vigour index. Data collected on seed viability and seedling vigour were analyzed using ANOVA, mean separation using Duncan Multiple Range Test at 5% probability level and PROBIT analysis. The results showed differential responses in the two quality traits due to differences in storage location and varieties. Ibadan storage location provided more favourable conditions for higher seed quality compared to Abeokuta location while Ifeken 400 and Tianung had the best storage potential. The study showed that under ambient humid tropical conditions, storage period should not exceed 180 days (6 months) in order to maintain higher physiological quality with little or no cost. The PROBIT result revealed that the highest seed shelf life (longevity) of kenaf seeds of 8 to 9 months was derived for seeds of Ifeken 400 and Tianung stored in Ibadan and Abeokuta. The shortest shelf life of 6 months was estimated for Ifeken 100 stored in both locations
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Plant Breeding and Seed Science 2012 67 M.A. Adebisi, T.O. Kehinde, J.B.O. Porbeni, S. Oduwaye, K. Biliaminu, S.A. Akintunde Seeds and seedlings vigour in tropical maize inbred lines
Seed and seedling vigour is an aspect of seed quality which affects field establishment and performance. Low maize yields have been reported to be affected by several factors in which poor quality seed with low seed and seedling vigour. Information is scarce on seed and seedling vigour in maize inbred lines developed for tropical environments. Fifteen genotypes of tropical maize (Zea mays L.) inbred lines were evaluated to determine the level of differences in seed and seedling vigour traits, and extent of relationships among traits and their heritability. A substantial amount of genetic variability was found, which suggested that most of the traits under study could be improved through selection and utilized in breeding programs. Positive and significant interrelationship among seed germination and seedling traits and a positive correlation between seed germination and seed vigour and field emergence showed that these could be given due consideration in crop improvement for seed and seedling vigour. High genotypic coefficient of variation, heritability and genetic advance were obtained for seed germination, seed emergence, shoot length and seedling vigour index I and II, revealing the possibility of improvement in these characters through direct selection. The principal component analysis (PCA) identified seed emergence, shoot length, seedling vigour index I and II and tetrazolium vigour as characters that contributed greatly to variation in seed vigour in the maize inbred lines. Cluster analysis partitioned the genotypes into two groups, with group I consisting of seven genotypes and group II comprised the other eight genotypes, which suggested that hybridization between the two groups could lead to high level of heterosis. Genotype V5 had superior seedling vigour traits compared to other genotypes. Seedling emergence, shoot length, seedling vigour index I, seedling vigour index II and tetrazolium vigour are effective characters for good seedling vigour traits in maize inbred lines investigated.
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Plant Breeding and Seed Science 2012 67 O.A. Oduwaye, D.K. Ojo, J. Mkumbira, C.O. Alake, O. Adenuga, E.F.Mapayi Genetic assessment of 23 cassava, Manihot esculenta Crantz, genotypes at two agroclimatic zones in Nigeria
This study investigated genetic diversity among 23 cassava genotypes in two-agro-ecological zones (Ibadan and Mokwa), Nigeria. The experiment was conducted using a randomized complete block design with three replicates. The cassava genotypes were evaluated for tuber yield, fresh weight of tuber, number of tubers, tuber girth and length, dry matter and chlorophyll concentration. The data collected were subjected to analysis of variance and differences among the genotypes were computed using Duncan’s multiple range test. Single linkage cluster and FASTCLUS analysis were used to group the cassava genotypes. Genotypic and phenotypic coefficient of variability, heritability and genetic advance were also evaluated. Genotype, environment and genotype × environment interaction (GEI) were significant (P < 0.01) for most of the traits evaluated. The magnitude of the environment was higher compared to genotype and GEI. Comparative mean performance varied from location to location. Tuber yield ranged from 0.32 for 92/0325 to 0.90 kg for 99/3073 with mean of 0.58 kg, and 0.16 kg for 82/00058 to 0.67 kg for 98/0581 with mean of 0.35 kg in Mokwa. Higher genotypic and phenotypic coefficients of variability were observed in Ibadan than Mokwa, for most of the characters. The interrelationships among the characters revealed the superiority of some cassava genotypes for a character in one location and not in the other location. However, breeding potentials exists among the cassava genotypes across the two environments.
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Plant Breeding and Seed Science 2012 67 H.Saeb, M.Khayyat, A.Zarezadeh, F.Moradinezhad, A.Samadzadeh, M.Safaee Effects of NaCl stress on seed germination attributes of periwinkle (Catharanthus roseus L.) and corn poppy (Papaver rhoeas L.) plants
The present research was conducted to evaluate the effects of salinized water with NaCl on seed germination of Periwinkle and Corn Poppy. Treatments were: A) H2O- distilled water (control); B) sodium chloride solutions (5, 10, 20, 40 and 80 mM). Application of the highest NaCl concentration (80mM) significantly reduced germination percentage and mean germination time of both species, although increased the day of 50% germination. Increment of salinity concentration was led to the reduction of radicle length in Periwinkle. The seedling fresh weight and water content and radicle length of Corn Poppy were decreased in both levels of 20 and 80 mM, and seedling dry weight was unaffected by treatments. It is concluded that both species are tolerant to NaCl salinity up to 80 mM during germination stage.
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Plant Breeding and Seed Science 2012 67 Akbar Marzooghian, Mohammad Moghaddam, Mostafa Valizadeh, Mohammad Hasan Kooshki Genetic diversity of common bean genotypes as revealed by seed storage proteins and some agronomic traits
Evaluation of the genetic diversity present within species is essential for conservation, management and utilization of the genetic resources. The objective of this study was to evaluate genetic variability of 70 common bean genotypes for seed storage proteins, grain morphological characteristics and agronomic traits. Two methods of extracting soluble seed proteins in salt were used. Positive correlations were observed among both seed morphological characters and developmental characters while yield components showed negative correlations with each other. Factor analysis for agronomic and grain morphological traits resulted in three factors were named yield components, seed morphology and phenology, respectively. Most genotypes had lower or medium scores for yield components and phenology factors. Considerable diversity was observed for seed morphology factor among the common bean genotypes. Nei’s diversity coefficient (He = 0.4), effective number of alleles (Ae = 1.69) and number of polymorphic loci (N = 17) indicated larger variation in the extraction method of soluble proteins in low salt (0.2 M NaCl) than high salt (1 M NaCl) condition. Considering that the centers of diversity for common bean are different in seed size, the result of GST statistics showed that bands with relative mobility of 30, 32, 38 and 40 differentiated two weight groups more than other bands. Furthermore, significant differences were observed between these bands for number of pods per plant and number of seeds per plant.
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Plant Breeding and Seed Science 2012 66 Sylwia Ciaglo-Androsiuk Relationship between root and yield related morphological characters in pea (Pisum sativum L.)
Relation between morphological traits of the root system and yield related traits is an important issue concerning efforts aiming at improving of ideotype of cultivated plants species, including pea. In this paper, to analyse the dependency between traits describing the root system morphology and yield potential, Person’s and Spearman's correlations as well as canonical correlations were used. Root system was analyzed in 14 and 21 day-old seedlings growing in blotting-paper cylinders. Yield potential of pea was analysed in a field experiment. Results of Person’s and Spearman's correlations revealed that number of lateral roots and lateral roots density were correlated witch yield related traits. Correlation between root length and shoot length was observed only for 14 day-old seedlings. The result of canonical correlations revealed that number of lateral roots and lateral roots density had the largest effect on yield related traits. This work highlights, that in order to improve the yield of pea it might become necessary to understand genetic determination of morphological traits of the root system, especially number of lateral roots.
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Plant Breeding and Seed Science 2012 66 Mohd. Shafi Khan, Vishal Singh Chandel, Rajiv Manohar, Jagdeesh Prasad Shukla Study of dielectric properties of fenugreek seeds (Trigonella foenum graecum)
The present paper studied the dielectric constant, dielectric loss, and ac conductivity of fenugreek seed, a medicinal seed (Trigonella foenum graecum), within the frequency range of 10 kHz and 10 MHz and the temperature range of 300C and 500C. Impedance gain/phase analyser (HP 4194 A) was used to measure the dielectric constant and the dielectric loss and Julabo (temperature controller, F-25, Germany) was used for keeping the temperature of fenugreek seeds constant. It was found that the dielectric constant and the dielectric loss decrease with the increase in the frequency while the same increase with the increase in temperature and moisture content. The ac conductivity increased with the increase in frequency, moisture and temperature.
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Plant Breeding and Seed Science 2012 66 Magdalena Gut, Przemysław Szecówka, Andrzej Bichoński Selected traits of spring wheat in Polish climatic conditions. Part 1. The traits of yield components and basic technological parameters
The purpose of the paper was to determine phenotype and genotype variability of yield components structure (number of grains, grain mass and 1000 grain weigh) as well as of the basic technological traits (sedimentation number, falling number, protein percentage content per grain). The research also considered the issue of pre-harvest sprouting. During each vegetation season rainfall and temperature were recorded. The examined material were the strains of F6 - F7 generation. Coefficients of correlation between the values of particular traits and mean temperatures and rainfall sum during a given season showed that yield component parameters were significantly modified by temperature; whilst warm vegetation seasons proved to be beneficial. Negative correlation between the rainfall sum and the number of grains and grain mass as well as 1000 grain weight suggests that the excess of water may be more detrimental for the yield than its shortage. Coefficients of correlation between the values of basic technological parameters and mean temperature were negative and not very high or low or even – insignificant, as in the case of falling number. High h2 coefficients suggest a good heritability of yield components parameters, and yield per ear seem to be the trait that was transmitted best. Amongst the basic quality indicators, the highest heritability was observed in the case of falling number and the lowest one in the case of sedimentation number. The weakest genetic conditioning was observed in the case of resistance to sprouting, measured as the percentage of sprouting grains in the ear. It seems therefore that genetic variability was, to a large degree, masked by the environmental impact and, in spite of a high degree of genetic conditioning, the effectiveness of selection based on a visual evaluation of the forms rated for further cultivation might be limited.
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Plant Breeding and Seed Science 2012 66 Danuta Martyniak, Grzegorz Żurek The effect of sowing quantity and row spacing on seed production of few minor grass species
A wide range of seed material from different grass species is necessary to keep high quality grasslands and to create buffer zones between arable lands and forest and to re-cultivate waste or fallow land. Therefore, the aim of our research was to describe elements of seed propagation of some minor grass species. On the basis of field experiments, different spacing and seed quantities were investigated for Beckmannia eruciformis, Cynosurus cristatus and Elytrigia elongata aiming at an optimal seed production. Satisfying seed yields were obtained even at a reduced (50% to 75%) amount of seed quantity, as compared to theoretical (or normal) values, calculated on the basis of number of plants per area unit.
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Plant Breeding and Seed Science 2012 66 C.O. Alake Variation and heritability of sixteen characters in West Africa okra, Abelmoschus caillei (A. chev) Stevels
Genotypic and phenotypic variances, genotypic and phenotypic coefficients of variation, heritability and genetic advance were estimated for 16 agronomical characters in West African okra for two seasons, using 25 West African okra lines of diverse origin. Considerable differences were observed for some characters in the two seasons. Number of days to flowering, number of leaves at flowering, plant height at flowering and number of pods at branches showed seasonal differences. The estimates of genotypic coefficients of variation (gcv) in the two seasons were close in many cases. The gcv values ranged from 1.41 for number of days to flowering in the early season to 68.63 for number of branches per plant in the late season planting. Heritability estimates ranged from 5.02% for number of leaves at flowering in the early season to 99.54% for weight of matured pod during the early season. This study highlighted the significance of genotype-environment interaction in the breeding programmes of West African okra. The relatively large genotypic coefficient of variation, heritability estimates and genetic advance for number of pods at stem, number of pods per plant, number of branches per plant, weight of matured pods and seed yield per plant, were indicative of likely effectiveness of selection for such characters.
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Plant Breeding and Seed Science 2012 66 Jadwiga Śliwka, Iga Tomczyńska, Marcin Chmielarz, Emil Stefańczyk, Renata Lebecka, Ewa Zimnoch-Guzowska Resistance of Phytophthora infestans in three Solanum nigrum F3 families
Solanum nigrum is a self-pollinating, hexaploid weed and one of a few Solanaceae species native to Europe. It used to be described as a non-host for Phytophthora infestans. However, now it is known that, like its distant relatives: potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.), S. nigrum can suffer from potato late blight caused by this pathogen. Both susceptible and resistant S. nigrum genotypes have been previously identified and inheritance of resistance originating from one accession has been described based on population of F2 plants and 15 F3 lines. The goal of this study was to evaluate resistance of three families of F3 lines, originating from crosses between a susceptible and three different resistant S. nigrum accessions followed by two self-pollinations. Parental accessions were tested for the spectrum of late blight resistance against 48 P. infestans isolates. The three families consisted of 106, 96 and 115 F3 lines, respectively, and from each line 20 plants were tested for resistance to P. infestans. Laboratory detached leaf assays were performed in two dates and two replications of three leaves each. Segregation of the trait within the line allowed us to distinguish hetero- and homozygous lines. In one F3 family, the ratio of resistant homozygotes: heterozygotes: susceptible homozygotes was 1:2:1, indicating that a single gene is most likely underlying the late blight resistance in this case. In the other two, observed segregations of the trait significantly deviated from this model suggesting more complex inheritance patterns.
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Plant Breeding and Seed Science 2012 66 Norma Paola Meléndez Rentería, Veronica Padilla, Gerardo Gaona Lozano, Cristobal Noe Aguilar, Raúl Rodríguez-Herrera Genetic variability of sotol (Dasyrylion cedrosanum) populations in the Mexican Coahuila southern area
In the Chihuahuan desert area, in Mexico, exist an endemic plant denominated Sotol (Dasylirion spp); which is used by rural producers to manufacture a liqueur named Sotol. This beverage has origin denomination but it industrial application has lack scientific reports, as well as the plant genetic information. This is the first study about ecological distribution of sotol plants and, may be, a first step to continue the scientific investigation of a Mexican endemic plant, with many potential industrial applications. In this paper, we used AFLP molecular markers to calculate population genetics parameters as genetic diversity, a conglomerate analyses, poblational structure based in Wright´s statistics and analysis of molecular variance. Differences in soil composition and weather conditions, of the sampling region, may affect sotol plants growth and their morphologic characteristics; as consequence the organisms generate ample genetic variability, which ensures the species permanence. Genetic diversity values were similar to the average for cross-pollinated plants, while the heterozygosis detection was deficient; Wright statistics suggest plants genetics interchange in the subpopulation; AMOVA found significant differences within and between collections. These results help us to maintenance the genetic diversity, in order to prevent potential extinction and guarantee sustainable development; the preservation of the endemic plants is necessary to the ecosystems conservation and after Sotol origin denomination, by the Mexican government, the importance of D. cedrosanum plants was increased.
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Plant Breeding and Seed Science 2012 66 Chaffei Haouari Chiraz, Hajjaji Nasraoui Afef, Bouthour Donia, Gouia Houda Variations in a-, b-amylase and a-glycosidase activities in two genotypes of wheat under NaCl salinity stress
Two wheat differing in salt sensitivity, was examined for osmolyte contents and activities of amylase, amylase and glucosidase enzymes involved in seeds germination, in absence as well as in presence of 100, 150, 200 and 300 mM NaCl. The inhibitory effects of NaCl differed, depending on the species tested. In wild wheat specie (Triticum monococcum), with reduced germination percentage and lower relative water content, the increase in NaCl concentration resulted in the decrease in endogenous level of proline, total soluble sugars and activities of the main enzymes involved in the germination process. In contrast, cultivated wheat specie (Triticum aestivum) seed in response to salt stress accumulated higher proline and total soluble carbohydrate concentrations which improved their water status and the enzyme activities involved in the germination process. Differential response of the different species of wheat to salt stress is governed by the accumulation of osmolytes in seeds
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Plant Breeding and Seed Science 2012 66 Christof Morteza Saberi, Farajollah Tarnian Effect of seed priming on improvement of germination of Vicia villosa under allelopathic components of Eucalyptus camaldulensis
The objective of this study was to evaluate the effectiveness of seed priming in improving seed germination and seedling vigor of Vicia villosa under laboratory conditions. Chemical stimulators included: gibberellic acid (125,250 and 500 ppm), salicylic acid (100,200 and 300 mg/lit) and extract of Eucalyptus camaldulensis (0, 25, 50, 75 and 100 %). This experiment was carried out as factorial experiment based on a randomized completely design, with four replications. The results showed that Eucalyptus camaldulensis extract had inhibitive effect on germination and early seedling growth of Vicia villosa. Early seedling growth of Vicia villosa increased by pretreatment of seeds in chemical stimulators so that the highest effect was observed in gibberellic acid (250 ppm). The chemical stimulators don’t have any effect on germination speed. Interaction effects of allelopathic and pretreatment with chemical stimulators were significance on germination percentage, root, shoot and plant length and seed vigor index.
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Plant Breeding and Seed Science 2012 66 Elham Nikmanesh, Mohammadhadi Pahlevani, Seyed Esmaeil Razavi Selection-based heritability of resistance to Pythium ultimum in safflower
Damping-off disease caused by Pythium ultimum can kill both germinating seeds and young seedlings and cause considerable damage in safflower cultivation. An estimation of heritability lets safflower breeders determine the most effective method for improving seedling emergence in soils infected with P. ultimum, the causal agent of seed rot and damping-off. Two cycles of selection were performed to estimate the realized heritability of resistance to the pathogen in five safflower populations. Undamaged seedlings were selected as resistant individuals and were kept to produce seed. The results showed that selection for two consecutive generations increased the emergence of seedlings in Pythium-infected soil from 46 to 53 %. The heritability estimates varied between 1.72 and 77.66 % over the genotypes and environments, in inverse proportion to the severity of the disease. Estimates of heritabilities showed that genes conferring resistance to P. ultimum in safflower are highly heritable and would respond to selection breeding, particularly in some of the studied genotypes, like Isfahan and Zarghan259. However, different breeding methods must be explored for other genotypes.
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Plant Breeding and Seed Science 2012 66 Naser Sabaghnia, Mohtasham Mohammadi, Rahmatollah Karimizadeh Clustering durum wheat genotypes in multi-environmental trials of rain-fed conditions
For durum wheat genotypes evaluation in multi-environmental trials (MET), measured seed yield is the combined result of effects of genotype (G), environment (E) and genotype by environment GE interaction. The GE interaction structure can be identified if the data are stratified into homogeneous subsets through cluster analysis. A combined analysis to assess GE interactions of 20 durum wheat genotypes across 14 environments was undertaken. The combined analysis of variance for E, G and GE interaction was significant, suggesting differential responses of the genotypes in various environments. Four cluster methods, which differ in the dissimilarity indices depending on the regression model or ANOVA model, were used. According to dendograms of regression methods there were 10 different genotypic groups based on G (intercept) and GE (line slope) sources and 3 different genotypic groups based on GE (line slope) sources. Also, the dendograms of ANOVA methods indicated 11 different genotypic groups based on G and GE sources and 13 different genotypic groups based on GE sources. The above mentioned genotypic groups were determined via F-test as an empirical stopping criterion for clustering. Due to the high values of regression’s determination coefficient which ranged from 92.6 to 99.4, using of the linear regression-based clustering was more practical. The genotypes clustering based on similarity of linear regression parameters or ANOVA model indicated that there were considerable variations among durum wheat genotypes and there are different with each other in response to environmental changes. Such an outcome could be regularly applied in the future to clattering durum wheat genotypes and other crops based on regression or ANOVA models in the Middle East and other areas of the world .
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Plant Breeding and Seed Science 2012 66 H. Bagmohammadi, M. Pahlevani, A. Ahmadikhah, S.E. Razavi Genetic variation of safflower (Carthamus tinctorius L.) and related species revealed by ISSR analysis
Genetic diversity of eight genotypes of Carthamus tinctorius L., two populations of C. oxyacanthus, and one population of C. lanatus was investigated using inter-simple sequence repeat (ISSR) markers. All samples were uniquely distinguished by 10 ISSR primers with 144 bands which generated 100% polymorphism. Furthermore, the ISSR markers could separate three safflower species properly, that highlights the effectiveness of this marker system for phylogenetic studies. The most and least informative primers were ISSR9 (PIC=0.367) and ISSR2 (PIC=0.254), and some primers were more efficient in detecting polymorphism in one species than for the others. Unweighed pair-group method with arithmetical averages (UPGMA) cluster analysis enabled construction of a dendrogram for estimating genetic distances among different populations. The result of cluster analysis suggested that cultivated and wild populations of C. oxyacanthus had close relationship with each other and far relationship with C. lanatus. The extreme genetic dissimilarity was observed between genotypes of C. tinctorius and C. lanatus populations. Based on the results, C. oxyacanthus could introduce favorable genes to cultivated safflower via inter-specific hybridization in breeding programs. Nei’s gene diversity index, Shannon’s index and percent of polymorphic loci showed that Isfahan ecotype of C. oxyacanthus had the highest variation at DNA level in relation to populations of other species. The ISSRs developed in this research along with those recently studied by other researchers will contribute to construct genetic map with a density sufficient for safflower molecular breeding.
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Plant Breeding and Seed Science 2012 65 Andrzej Dziamski, Zofia Stypczyńska, Grzegorz Żurek Estimation of root and shoot growth of selected grass species on the basis of seedling characterization
Our study was designed to describe possibilities to estimate above- and below ground biomass of selected grass species by means of seedling development. Festuca arundinacea Schreb., Festuca rubra L., Lolium perenne L., Poa pratensis L., Koeleria macrantha (Ledeb.) Schultes, Deschampsia caespitosa (L.) P.B. were used in our experiment. On the basis of observations and measurements, differences between species, cultivars and ecotypes were described. Significant and positive correlation was found between root:shoot ratio at seedling phase and at mature plants.
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Plant Breeding and Seed Science 2012 65 Matthew Hal, Jenny Jobling, Gordon Rogers The germination of perennial wall rocket (Diplotaxis tenuifolia [L.] DC.) and annual garden rocket (Eruca sativa Mill.) under controlled temperatures
The germination characteristics of three cultivars of perennial wall rocket and annual garden rocket were assessed at constant and diurnal temperatures for ten days. The seeds were exposed to constant temperatures of 5, 10, 15, 20, 25, 30 and 35°C or diurnal temperatures of 24/10, 28/16 and 18/5°C, with a 12/12 h exposure of each regime. The diurnal temperatures were chosen to reflect the minimum and maximum ambient temperatures experienced in Ellis Lane, Australia; during the spring, summer and winter. The total germination percentage (TGP) of perennial wall rocket was the highest at 20 to 30°C, whereas the highest TGP occurred at 10 to 30°C for annual garden rocket. The daily germination speed (DGS) and germination value (GV) are two useful formulas used to express the germination characteristics of seeds that under certain conditions do not achieve ≥50% germination. For both species, there was a significant interaction between the cultivar and temperature for the DGS and GV at both constant and diurnal temperatures; illustrating that the commercial cultivars of these species germinate at different rates in response to different ambient temperatures. This has important implications for the commercial production of these species, as cultivars with high germination rates need to be chosen for different seasonal conditions. At diurnal temperatures, there was an interaction between the cultivar and temperature for perennial wall rocket, with the cvs. DT1 and DT2 having similar TGPs across all of the temperature regimes, whereas the cv. DT3 had lower TGPs across all of the regimes. There was no interaction between the cultivar and diurnal temperature for annual garden rocket; however, temperature did influence the TGP, with higher values at 24/10 and 18/5°C. The germination of the smaller seeds from the perennial species was found to be more dependent on temperature than the larger seeds from the annual species. This is likely due to differences in stored reserves and the influence of secondary dormancy in the respective species.
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Plant Breeding and Seed Science 2012 65 Rajib Roychowdhury, Molla Jannatul Ferdousul Alam, Sunanda Bishnu, Tinkari Dalal, Jagatpati Tah Comparative study for effects of chemical mutagenesis on seed germination, survivability and pollen sterility in M1 and M2 generations of Dianthus
Chemical mutagenesis is an efficient tool used in mutation breeding programme for improving various vital characteristics in floricultural crop, like Dianthus. In this study, ethyl methane sulphonate (EMS), sodium azide (SA) and colchicine (COL) with three different concentrations (0.1%, 0.4% and 0.7%) were used to analyse their effect on seed germination behaviour, survivability and pollen sterility in both first (M1) and second (M2) mutant generations. It was noted that increase in the dose of EMS and SA, germination percentage and survivability were decreased; whereas colchicine doses were proportional to increase germination percentage at seedling stage, but they were not survived till maturity. In M1 and M2, higher lethality over control (44.3 and 32.89, respectively) was shown by 0.7% of SA and EMS, respectively. Pollen sterility was also increased with increasing mutagenic doses. The maximum pollen sterility was 71.8% and 61.1% for 0.7% COL in M1 and M2, respectively. So, the effect of chemical mutagenesis on biological parameters with SA (0.7%) treatment in M1 and EMS (0.7%) treatment in M2 were much more beneficial as compared to colchicine. For each studied parameter, chemical mutagenesis was higher in M1 than M2. Hence, for the first time in Dianthus, we reported that these mutagens can be used for improving the germination behaviour and the metrical traits in Dianthus cultivar.
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Plant Breeding and Seed Science 2012 65 Valiollah Rameeh Combining ability analysis of some of grain yield stress indices in rapeseed (Brassica napus L.) varieties
Although most of investigations showed that nitrogen fertilizers gave substantial rapeseed yield increases even in diverse and contradicting conditions but in a few studies were focused on genetic parameters of nitrogen stress effects. Combining ability of some of important grain yield stress indices based on application and non application of nitrogen (N+ and N0) was studied using half diallel of six spring rapeseed varieties and their 15 F2 progenies. Significant mean squares of general and specific combining abilities (GCA and SCA) were observed for potential yield(Yp), Stress yield(Ys), mean productivity (MP), geometric mean productivity (GMP), tolerance index (TOL), stress tolerance index (STI) and stress susceptibility index (SSI), indicating importance of additive and non-additive genetic effects for them. Non significant ratio of GCA to SCA mean square and low narrow-sense heritability estimates were detected for all the indices, indicating the prime importance of non-additive genetic effects. Significant positive GCA effect of Yp, Ys, MP, GMP and STI for PF7045/91 and significant negative GCA effects of them for Option500, indicated the same direction of GCA effects of these indices and GCA effects of Yp and Ys. On compare to SCA effects, most of crosses had significant high parent heterosis for Yp, Ys and and all the stress indices, therefore selection the better combinations based on heterosis will be more effective than SCA effect.
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Plant Breeding and Seed Science 2012 65 Barbara Wiewióra The effect of seed health of perennial ryegrass (Lolium perenne L.) on germination capacity
The analysis of seed health and germination capacity of 7 varieties of Lolium perenne, originated from two breeding station and two seed company localized in different places of Poland, harvested in 2006, 2007 and 2008 were performed. Results of mentioned analysis indicated that seeds were contaminated by numerous species of fungi. The most numerous group of fungi were saprophytes or weak parasites such as: Alternaria alternata, Epicoccum nigrum, Septonema chaetospira and Penicillium spp. Pathogenic species were represented by species of Drechslera, Fusarium, Phoma, Curvularia lunata and Bipolaris sorokiniana. Seed germination capacity was influenced by contamination of fungi. It was found that seed more often contaminated by fungi germinated much poorer then seed with lower infection.
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Plant Breeding and Seed Science 2012 65 DeFang Zeng, Xiang Mei Application of a natural aminopolysaccharide in seed film-coating for pest control and cotton growth
Cotton suffers attacks of various pests that result in a decreased yield. Until recently, the chemical control of pests was achieved through seed film-coating treatment with toxic insecticides. The natural aminopolysaccharide extracts from crab is a promising candidate as a repellent to protect cotton from Aphis gossypii Glover and Helicoverpa armigera Hubner. Experiments were conducted to study the effect of aminopolysaccharide on pest control, seed germination, plant growth and lint yield. Results indicated that all aminopolysaccharide treatments of different content repelled pests efficiently and increased significantly seed germination, plant growth and cotton yield. The natural aminopolysaccharide extracts from shrimp is a promising candidate as a repellent to protect cotton from Aphis gossypii Glover and Helicoverpa armigera Hubner. The application of the potential aminopolysaccharide by seed coating is an appropriate option for controlling pests and avoiding environmental pollution.
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Plant Breeding and Seed Science 2012 65 Ghazala Nasim, Sobia Mushtaq, Irum Mukhtar, Ibatsam Khokhar Effect of Penicillium extractsa on germination vigor in subsequent seedling growth of tomato (Solanum lycopersicum L.)
Penicillium spp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of different Penicillium spp. were tested on tomato seeds. On the whole, presoaking of seeds in filtrates of the nine Penicillium isolates tested, significantly increased seed germination when compared with the control seeds. Cultural extracts of P. expensum and P. billi were highly effective in growth promotion up to 90%. It was also observed that P. implicatum and P. oxlalicam significantly enhanced the root growth in tomato seedling as compare to other species. In case of shoot length, P. verrucosum (3.38), P. granulatum (2.81) and P. implicatum (2.62) were effective. However P. implicatum was quite promising to increase shoot and root length in tomato seedlings. Where as P. simplicissimium and P. citrinum were leas effective on seedling growth. The plant growth promoting ability of Penicillium strains may help in growth permotion in other plants and crops. Penicillium spp. are already known for producing mycotoxin and enzymes. Plant growth promoting ability of Penicillium spp will open new aspects of research and investigations. The role of Penicillium spp. in tomato plant growth requires further exploration.
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Plant Breeding and Seed Science 2012 65 Lech Boros Evaluation of stability of field pea genotypes in response to Mycosphaerella pinodes infection
Interaction of genotypes with environment for quantitative traits among them certain disease resistance makes difficult choice of proper genotypes for breeding proposes and may affects further cultivation effects. The aim of this study was assessment of stability of reaction to Mycosphaerella pinodes infection for the set of pea genotypes in four years field experiments with vary epidemic pressure. The Sheffé-Caliński mixed model and the Caliński-Kaczmarek joint regression model for genotype-environment interaction analysis was applied. Tested pea genotypes were grouped into two categories; responding stable to M. pinodes (reacting proportionally to changed environment) and unstable ones (showing significant interaction with environment). The unstable genotypes reacted irregularly to environments (not able to describe the reaction to M. pinodes by any linear regression function). Pea genotypes PI 142441, PI 142442, PI 404221, PI 413691, cv. Radley and Bohun were characterized by high negative main effects (most resistant) for disease severity and showed stable response to M. pinodes infection. Stability of mycospharealla blight reactions was not associated with the level of resistance in the cultivars tested.
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Plant Breeding and Seed Science 2012 65 J.A. Olfati, H. Samizadeh, Gh. Peyvast, B. Rabiei, S.A. Khodaparast Relationships between hybrid performance and genetic distance revealed by morphological and AFLP marker in cucumber
This study investigated the relationship of morphological and molecular genetic distance with hybrid performance and heterosis in cucumber in an attempt to make use of genetic distance in predicting hybrid performance. The results of this study showed that GD, in general, correlated poorly with heterosis and SCA. Results showed that the mean values of the hybrids were significantly larger or smaller for many traits when compared with the mean of parental lines, indicating that heterosis was present for these traits. In next step we compare inter group hybrids versus intra group hybrids. This test showed that intra group hybridization although increased the yield and yield component but decrease some fruit quality such as fruit color and shape.
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Plant Breeding and Seed Science 2012 65 Sivapuram Venkata Rama Krishna Prabhakar, N.T. Yaduraju, Malavika Dadlani, M. Gopal Effect of different cropping conditions, depth of burial, age of seeds, and allelopathic effect of different crops on the germi-nation behavior of little seed canary grass (Phalaris minor Retz.) seeds
Pot culture experiments were conducted to find out the effect of different cropping conditions, depth of burial and age of seeds on the survival of little seed canary grass (Phalaris minor Retz.) seeds. The results indicated that the soil temperature modifications through the flooding or filed capacity moisture status of the soil influenced the germination and viability of the buried weed seeds rather than the crops per se. It was observed that the seeds lost their viability because of the anaerobic conditions and high temperatures and through increased membrane permeability of the seeds. The P. minor Retz. seeds were found to be sensitive to anaerobic conditions. The longevity of seeds buried in rice-wheat system and Flooding-wheat system was found low when compared to those buried under soybean-wheat and field capacity-wheat conditions. The in situ effect of rainy season (kharif) crops was found to confine to influencing the initial germination (vigor) of the little seed canary grass with cowpea, groundnut, soybean and sunflower inhibiting the initial germination of little seed canary grass. This inhibition was absent at the end of germination counts taken after twenty days after keeping for germination. The residual effect of cowpea, rice, soybean and sunflower was observed. The application of pearl millet and rice residues has considerably reduced the little seed canary grass germination, plant height, seedling fresh weight and leaf area at thirty days after sowing.
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Plant Breeding and Seed Science 2011 64 J. Czaban, B. Wróblewska, A. Sułek, G. Podolska Colonization of wheat grain by Fusaria in two crop management systems varying in intensity of production technology.
The purpose of this study was to investigate the effects of two cropping systems (intensive and integrated) on infection level of winter and spring wheat kernels by Fusarium species. Field experiments were conducted with winter wheat ‘Tonacja’ and spring wheat ‘Bombona’ during two consecutive growing seasons (2007/2008 and 2008/2009 - winter wheat, and 2008 and 2009 - spring wheat). A rainfall level in 2009 from the last decade of May to the first decade of July was 2.5-times higher than that in 2008. After the harvest, kernels were surface disinfected with 1.5% NaOCl solution for 2 min and then analysed for the infection level by different species of Fusarium. Fusaria were isolated on CZID medium and identified on the basis of macro- and micro-morphology on three media (PDA, SNA and a medium containing tannin). Our results demonstrate that the wheat grain infection by Fusarium depended mainly on a rainfall level. The intensive cropping system was more conducive to the grain infection by fusaria in comparison to the integrated one. The most frequent species were F. avenaceum in 2008, and F. graminearum, F. avenaceum and F. poae in 2009...
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Plant Breeding and Seed Science 2011 64 T. Gagkaeva, O. Gavrilova, T. Yli-Mattila, I. Loskutov Evaluation of oat germplasm for resistance to Fusarium Head Blight.
The objectives of this study were to screen the VIR Avena germplasm collection for Fusarium head blight (FHB) resistance and to identify the resistant oat genotypes by using the different scoring of the disease. After artificial inoculation harvested grain samples were assays on the combination of three parameters: percentage of Fusarium damaged kernels (FDK), DNA of trichothecene-producing Fusarium fungi and mycotoxin accumulation. The clear correlation between the parameters for every individual genotype was not detected. The results support the several components of resistance to Fusarium head blight in oats (invasion, spreading and mycotoxin accumulation), which are controlled by different genetic systems. The hull-less genotypes considered to be more resistant in the Avena germplasm. Seven landraces genotypes and five cultivars originated from Asian region and two cultivars originated from European region seem to be suitable genetic resources for resistance to FHB...
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Plant Breeding and Seed Science 2011 64 Leszek Lenc Pathogenicity and potential capacity for producing mycotoxins by Fusarium sambucinum and Fusarium solani isolates derived from potato tubers.
Studies of potential abilities of F. sambucinum to produce trichothecenes was conducted on isolates previously confirmed as belonging to this species by PCR. In all cases, A positive result for the presence of Tri5 gene, coding the ability to synthesize these mycotoxins. There was no potential to synthesize trichothecenes by F. solani. Further analysis concerned the potential ability of F. sambucinum to produce group B trichothecenes (DON and NIV). No isolate gave the expected amplification product (282 bp for deoxynivalenol and 312 bp for nivalenol), which would indicate the potential for producing these mycotoxins. Studies have shown the ability to produce trichothecenes of group A.Analysis of the potential ability for the synthesis of enniatins by F. sambucinum showed that 91% of isolates gave of 332 bp amplification product, which proves them as potencial producers of these mycotoxins. There were significant differences in the pathogenicity of F. sambucinum and F. solani represented by the size of decay caused by these species. The rotten tissue area caused by F. sambucinum was about 10 times bigger than after inoculation by F. solani. Furthermore, isolates within the same species (F. sambucinum) showed diverse pathogenicity. It should be noted, however, that the concentration of mycotoxins does not depend on the size of rotten tissue of potato tubers. Isolate, which caused the most severe disease symptoms, produced low concentrations of mycotoxins...
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Plant Breeding and Seed Science 2011 64 E. Nagy, V. Haş, I. Haş, A. Suciu, V. Florian The influence of Fusarium ear infection on the maize yield and mycotoxin content (Transylvania-Romania).
Maize is the host for a large number of pathogens, which invade all of its organs from the germination until being harvest, ear and grain infection often persistent even during storage. Diseases, through their symptoms reduce significantly the quantity and the quality of yield, estimated between 7-17% but, in the favorable years for this disease, they can be much greater. Fusarium diseases reduce yield value and quality by massive accumulation of Fusarium mycelium biomass (about 85%) on grain and ears and by mycotoxin contamination such as deoxynivalenol (DON), zearalenone (ZEA) and fumonisins (FUM). In this paper are presented aspects regarding the reaction of some maize hybrids under Fusarium spp. natural and artificial infections; the effect of Fusarium ear infection on yield, grain chemical composition, and mycotoxin content; the correlation between ear rot disease degree and yield ability, starch, protein and fat content. ANOVA evidenced the significant influence of experimental factors: infection conditions with Fusarium spp., maize genotypes, and their interaction on expression of the disease degree, yield capacity, protein, starch, fat and DON content. Average yield losses ranged between 7,0-9,3% during the experimental period. The hybrids Turda Star and Turda Favorit were more resistant to Fusarium ear rot, and Turda 165 was the most susceptible one. The artificial infection of ear with Fusarium spp. determined significantly decrease of starch and fat content and increases the protein and DON content for the most part of maize hybrids. Between rot diseased kernels and DON content a positive correlation was determined...
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Plant Breeding and Seed Science 2011 64 Mehdi Nasr Esfahani Comparative pathogenesity of Fusarium species on some of the potato cultivars.
The fusarium dry rot is one of the most important diseases of potato tubers causing considerable damages during the storage. Resistance sources are one of the fundamental methods in prevention and disease control. This study details the pathogenesity and assessment of susceptibility of commercially acceptable potato Cultivars to dry rot causing by Fusarium sulphureum , F. solani and F. oxysporum under similar conditions includings . inoculum , mehtod of inoculation, temperature , relative humidity and light. The results indicated that though the similar conditions were applied, the tubers of varieties reacted with differing levels of resistance to the species causing the disease. It was found that F. sulphureum was the most aggressive one, then fallowed by F. solani as far as the disease development is concerned and were independent. F. oxysporum did not cause considerable damages. In these expriments the commerical potato varieties were Seuminar, Rustica, clivastave, Dital, Escort, Monalisa, Marfona, Mondial, Aniona, Deraga, Asta, Hidram, Melisa, Moren, Mariyana, Pashandi, Frasco, Alva, Ceaser, Asva, Aula, Sandara , Marijke, Folva, Tiva, Fregate, Baraka, Aida, Diamant, Arnica, Panda, Atlas, Erigo, Volkano, Famosa, Carlita, Korrigan, Casmos, Assour, Cosima, Ariane, Desiree and saturna, in which started with most susceptible ones fallowed to resistance ones at end to F.sulphureum. The variety saturna were the most resistant one to the all tested species in these expriments...
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Plant Breeding and Seed Science 2011 64 Nelson Opoku, Matthew Back, Simon G. Edwards Aggressiveness of Fusarium langsethiae isolates towards wheat, barley and oats in an in vitro leaf assay.
Fusarium langsethiae has been identified as the primary producer of HT-2 and T-2 in European cereals. HT-2 and T-2 are considered as two of the most potent trichothecenes mycotoxins and a public health concern in Europe. There is currently no legislation on HT-2 and T-2, however, there is a discussion limit of 500 µg kg-1 in unprocessed oats, 200 µg kg-1 for oat products and 50 µg kg-1 for infant food. There are limited data regarding F. langsethiae’s pathogenicity and mycotoxin production, but it is evident that its behaviour deviates from traditional trichothecene-producing Fusarium species. This experiment was aimed at assessing the aggressiveness (measured by lesion length) of 20 different F. langsethiae isolates on wheat, barley and oats using an in vitro detached leaf assay. There was a significant (P
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Plant Breeding and Seed Science 2011 64 H. Pettersson Toxicity and risks with T-2 and HT-2 toxins in cereals.
The trichothecenes T-2 and HT-2 toxins have during recent years been found frequently in cereals grown in Europe. They are mainly produced by Fusarium langsethiae. High concentrations of the toxins are most commonly found in oats, but they are also detected frequently at lower concentrations in barley. Wheat is only rarely contaminated. Yearly surveys of T-2 and HT-2 toxins in oats from Northern Europe have shown that the occurrence and levels have increased from 2002, with very high levels in 2005-2007, followed by a decrease in 2008-2009.Raw oats delivered to mills for processing to food have also been highly contaminated with T-2 and HT-2 toxins during the period 2006-2009. The processing of oats in the mills by sorting-sieving and dehulling reduce the toxin concentrations in the final food products, flakes and meals, with more than 80 % even at high levels in the raw oat. The concentrations of the toxins in the by-products from the process are instead increased. The by-products are mainly used as feed components.The toxic effects of T-2 and HT-2 toxins in animals and the toxicological information used in the risk evaluations are briefly described. Risk evaluations of the toxins in cereals for human consumption have been conducted by both EU-Scientific Committee on Food and by JECFA in 2001. Both evaluations resulted in the same temporary tolerable daily intake (t-TDI) for the sum of T-2 and HT-2 toxins. The group TDI for T-2 and HT-2 toxins, alone or in combination, became 60 ng/kg bw and day.The intake of T-2 and HT-2 toxins through oats is calculated from median concentrations in oat products and median consumption data from Norway. The intake was found to be 1.5-5.4 % of the t-TDI.The toxic effects studied or expected in farm animals, horses and ruminants, consuming high amounts of oat in their feed are described and discussed...
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