The sulphur-rich Brazil nut 2S albumin is specifically formed in transgenic seeds of the grain legume Vicia narbonensis

Summary Epicotyl explants were co-cultivated with Agrobacterium tumefaciens EHA101 to transfer a chimeric 2S albumin gene construct carried in the binary Ti plasmid vectors pGSGLUC1 or pGA472 into the grain legume Vicia narbonensis. This gene encoding the sulphur-rich Brazil nut albumin was under the control of either the CaMV 35S promoter which permits gene expression in all organs, or the Vicia faba legumin B4 promoter which elicits seed-specific gene expression. After callus formation and selection for kanamycin resistance, somatic embryos were induced which, in the case of transformation with the vector pGSGLUC1, were screened for GUS activity. Embryos that produced GUS were in addition analysed for 2S albumin formation. Selected transgenic embryos were cloned by multiple shoot regeneration. Rooted and fertile plants were obtained by grafting transgenic shoots on the appropriate seedlings. R₁ and R₂ generations were raised and analysed for GUS as well as 2S albumin gene expression.Expression of the 35S promoter/2S albumin gene fusion took place in all organs of the transgenic plants including the cotyledons of seeds, whereas seed-specific gene expression was found in transformants with the legumin promoter/2S albumin gene fusion. The 2S albumin accumulated in the 2S protein fraction of transgenic seeds and its primary translation product was processed into the 9 and 3 kDa polypeptide chains. The foreign protein was localised in the protein bodies of the grain legume. Analysis of the R₂ plants indicated Mendelian inheritance of the 2S albumin gene. In homozygous V. narbonensis plants the amounts of 2S albumin were twice that present in the corresponding heterozygous plants. Whereas only low level formation of the foreign protein was achieved if the gene was under the control of the 35S promoter, approximately 3.0% of the soluble seed protein was 2S albumin if seed-specific gene expression was directed by the legumin B4 promoter. Some of these transformants exhibited a three-fold increase in the methionine content of the salt-soluble protein fraction extracted from seeds.Abbreviations 35S cauliflower mosaic virus 35S protein gene - GUS -glucuronidase - NPTII neomycin phosphotransferase II - LeB4 Vicia faba legumin B4 gene - 2S albumin Brazil nut (Bertholletia excelsa) 2S albumin - ER endoplasmic reticulum - rER rough endoplasmic reticulum - HPLC high pressure liquid chromatography     

Agronomic and morphological characterization of Agrobacterium-transformed Bt rice plants

The agronomic and morphological characteristics of Agrobacterium-transformed rice plants carrying the synthetic cry1Ab or cry1Ac gene were investigated. Tremendous variations in plant height, seed fertility, grain size and other traits were seen in 80 T₁ lines, derived from 80 T₀ plants of 9 rice varieties. On average, about 33% T₁ lines had either morphological or agronomic variant plants. Most of the variations in T₁ plants had no significant correlation with transgene insertion and were proved heritable to their progenies. Genetic analysis in T₃ or T₄ generations showed some simple mutations such as chlorophyll deficiency and stunted plants were independent of transgene insertion and seemed to be controlled by a pair of single genes. However, in two independent transgenic progenies of Xiushui 11, all plants homozygous for transgenes showed dwarfism while all hemizygous and null segregants had normal plant heights. Two advanced homozygous Bt lines, KMD1 and KMD2, were developed from these two progenies. Comparison of the agronomic traits of KMD1 and KMD2 with their parent displayed marked differences among them in terms of seedling growth, tillering ability, yield components and yield potential. The genetic variation observed was generally not linked to the transgene locus and was ascribed to somaclonal variation, but other causes might also exist in particular cases. The results are discussed in the context of choosing appropriate transformation methodology for rice breeding programs. This revised version was published online in August 2006 with corrections to the Cover Date.     

转BetA/als基因棉花材料的农艺性状考察

 以鲁棉研19转BetA/als基因的7个株系为材料,考察了这些株系的农艺性状。结果表明：外源基因BetA/als的导入对棉花各农艺性状有不同程度的影响,各性状变异系数增加。株系7-15、14-1的单株棉铃数、单个棉铃体积、果柄长、果枝夹角、衣分、子指、棉纤维2.5%跨长、比强度等性状与鲁棉研19相比差异不显著,铃重、子棉产量和皮棉产量提高,麦克隆值降低。株系7-15、14-1基本保持了原有品系优良农艺性状,在育种上可以将其作为BetA/als 基因的供体材料。     

The effect of T-DNA on the agronomic performance of transgenic flax plants

Summary Registration and commercial release of crop cultivars improved using recombinant DNA technologies will require extensive field testing of the transgenic lines. In addition to testing the efficacy of the transferred gene(s), regulatory bodies and farmers need data from large scale agronomic studies to provide assurance that the foreign DNA does not adversely affect normal agronomic productivity or quality of the crop. Here, five transgenic sulfonylurea resistant flax (Linum usitatissimum) lines were included in a multiple location cultivar registration trial, evaluated and compared with four standard commercial cultivars and 24 other (conventionally produced) breeding lines. The transgenic lines did not appear to be affected by T-DNA for any quality or agronomic parameter tested, including yield.     

Molecular markers for yield components in Brassica juncea – do these assist in breeding for high seed yield?

A population of 112 F₁-derived doubled haploid lines was produced from a reciprocal cross of Brassica juncea. The parents differed for seed quality, seed color and many agronomic traits. A detailed RFLP linkage map of this population, comprising 316 loci, had been constructed, and was used to map quantitative trait loci (QTL) for seed yield and yield components, viz. siliqua length, number of seeds per siliqua, number of siliques per main raceme and 1000-seed weight. Stable and significant QTLs were identified for all these yield components except seed yield. For yield components, a selection index based on combined phenotypic and molecular data (QTL effects) could double up the efficiency of selection compared to the expected genetic advance by phenotypic selection. Selection indices for high seed yield, based on the phenotypic data of yield and yield components, could only improve the efficiency of selection by 4% of the genetic advance that can be expected from direct phenotypic selection for yield alone. Inclusion of molecular data together with the phenotypic data of yield components in the selection indices did not improve the efficiency of selection for higher seed yield. This is probably due to often negative relationships among the yield components. Most of the QTLs for yield components were compensating each other, probably due to linkage, pleiotropy or developmentally induced relationships among them. The breeding strategy for B. juncea and challenges to marker assisted selection are discussed.     

Estimating agronomic traits of transgenic tobacco lines

Tobacco transgenic lines belonging to four cultivars modified with three genetic constructions providing the resistance to Potato virus Y (PVY) had been described as regards their agronomic and biological traits. The constructions included viral genes: the coat protein gene of Lettuce mosaic virus (LMV) and the replicase gene of PVY used in sense and antisense orientation. Evaluation of the chosen farm traits of the transgenic tobacco lines was performed by comparing them with their nontransgenic equivalents. The traits such as growth and development rate, height of stalks, leaf area, morphology of plants, course of meiosis and pollen viability were described. The cured leaves were analysed as regards to their physical traits and chemical composition. The individual transgenic lines differed from control cultivars to a little extent. Only insignificant changes, mainly in the quality of raw material were observed. Genetic modification did not cause any changes in the course of meiosis and pollen viability.     

Effect of sulphur levels on transgenic double-low Brassica napus plants expressing a seed-specific gene encoding a methionine-rich 2S albumin

The effects of supplying varying levels of sulphur to transgenic Brassica napus plants expressing the Brazil nut 2S albumin in their seeds were studied in the field. The aim was to determine if transgenic plants responded differently to such stress, and whether expression of the transgene would be effected. The transgenic plants were similar to normal plants in their response to sulphur stress. Increases in sulphur concentration were correlated with an increase in fresh and dry matter quantities as well as an increase in the carbon, nitrogen and sulphur levels in the vegetative parts of the plants. No effect on yield parameters was observed. Increasing sulphur levels resulted in an increase in the glucosinolate content, and shifts in fatty acid composition were observed. None of these changes could be correlated with the response of the transgene. The expression of the latter was altered at neither the mRNA nor The protein levels, presumably because the promoter used does not respond directly to sulphur level changes. The procedures used to create the transgenic plants in this work appear not to result in plants that respond to sulphur stress differently from normal plants in the ranges studied.     

QTL遗传效应正反交差异研究

应用改良AD模型对转基因棉花QTL突变体系进行遗传效应的正反交比较分析,结果表明,农艺性状的主要遗传方差组分分解正反交表现一致,除铃重存在显著的遗传背景加性效应(A2)外,子棉产量、皮棉产量、衣分和铃数均存在显著或极显著的 dQTL加性效应(A1)和显性效应(D1),农艺性状均有显著或极显著的遗传背景显性效应(D2);棉花纤维性状的主要遗传效应正反交之间无显著差异.铃重的dQTL的加性和显性效应与环境的互作存在显著差异.对转基因系、受体及三个品系的dQTL加性效应分解结果也表明,正反交对不同材料各性状的加性效应估计也是一致的.本文还对不同组合正反交时的纯合及杂合显性效应进行预测比较.     

Inheritance and field performance of transgenic Korean Bt rice lines resistant to rice yellow stem borer

Transgenic Korean rice plants containing the cry1Ab gene were developed for resistance against yellow stem borer (Scirpophaga incertulas, YSB). More than 100 independent transgenic lines from three Korean varieties (P-I, P-II and P-III) were generated. The amount of Cry1Ab in transgenic T₀ plants was as high as 2.88% of total soluble proteins. These levels were sufficient to cause 100% mortality of YSB larvae. The majority of T₁ transgenic lines originated from the varieties P-I and P-II followed a Mendelian fashion of segregation. Deviation from the expected segregation ratio was observed in a small number of the transgenic lines of P-I and P-II origins. However, this deviation was primarily observed in the P-III originated lines. Segregation analysis of the T₁ generation indicated that 1–3 copies of the cry1Ab gene were integrated into the genome of the majority of the transgenic lines originating from varieties P-I and P-II. Stunted and semi-fertile mutants were observed in some transgenic lines. These aberrations were either independent or closely linked to the introduced cry1Ab gene loci in different transgenic lines. Reduction in GUS expression levels and loss of toxicity against YSB larvae were found in some transgenic lines. The transgenic T₃ and T₄ lines causing 100% mortality of third instar YSB larvae in the lab were completely protected in the field. Analysis of important yield components on nine selected transgenic lines indicated that stem length, panicle length, grain number per panicle, and seed setting rates were reduced in transgenic plants compared to those in non-transgenic parental rice lines. Number of panicles per cluster, however, was significantly higher in transgenic plants. The numerical value of the average yield was in general greater in the controls than in all the transgenic lines, indicating some ‘yield drag’. Since some selected lines were highly resistant to the YSB with good yielding potential, they offer effective potential for use in insect resistance management programs.     

Further Characterization of rollC Transgenic Tetraploid Potato Clones, and Influence of Daylength and Level of rolC Expression on Yield Parameters

Tetraploid rolC transformants have been analyzed considering the level of rolC expression and yield parameters. In rolC transformants a maximum of five integrated copies of the gene were detected by Southern analysis. A relation between copy number of the rolC gene, phenotypic rolC expression and intensity of morphological alterations was established. Three experiments were performed to assess the differential effect of the rolC gene on yield and its interaction with growth factors. In the first experiment, the influence of day length on plant morphological and physiological characters was studied. The phenotype of the transgenic plants with a low rolC expression was like the control under the two day-regimes tested, while the intermediate expressing genotype showed a different reaction. In the second and third experiment, tuber yield, tuber number and weight per tuber were recorded under short and long day conditions. When grown in smaller pots of 1.15 1 volume, the control plants had the highest yield of tubers under both day lengths tested. Yield decreased with increasing rolC expression. Tuber number revealed to be genotype dependent: it was higher for low rolC expressing plants and lower for intermediate rolC transformants (Experiment 2). In the third experiment the influence of variable pot size and shape was analyzed for one clone with intermediate and two with low level of rolC expression. Remarkable differences between pots and flat boxes of the same volume were noted for tuber yield and number: Under the two conditions the control clone and the low rolC expressing genotypes gave similar tuber yield and number in both growth containers, whereas the rolC intermediate genotype yielded significantly more in flat boxes. The effect of variable hormonal levels induced in transgenic plants through prokaryotic genes are discussed with the existence of non-predictable genotype in relation to environmental interactions. It is concluded that at least the agronomic performance of potatoes transformed with these genes cannot be predicted on the basis of simple linear relationships among the expression of the gene and of the traits.     

Association of isozyme genotypes with agronomic and seed composition traits in soybean

Summary Two crosses between Glycine max (L.) Merr. and G. soja Sieb. & Zucc. parents were used to study the association between isozyme marker loci and agronomic and seed composition traits in soybean. The parents possessed different alleles at six isozyme loci for Cross 1 (A80-244036 × PI 326581) and at eight isozyme loci for Cross 2 (A81-157007 × PI 342618A). A total of 480 BC₂F_4:6 lines from the two crosses was evaluated for 13 traits in two environments. Lines were grouped in locus classes from 0 to 5 according to the number of loci homozygous for the G. soja alleles that they possessed. Within each locus class, each isozyme genotype was represented by five random lines.Selection for G. max alleles at the isozyme loci was not effective in recovering the recurrent parent phenotype in either cross. In cross 1, however, BC₂F₄-derived lines in the 0- or 1- locus class more closely resembled the G. max parent than lines in the 4- or 5- locus classes for most of the agronomic and seed composition traits evaluated. Significant associations were found between particular isozyme genotypes and every trait analyzed. The estimated effect of genes linked to the Pgm1 locus was a delay in maturity of 6.0±3.4 days. In cross 1, the Idh2 locus was associated with a significant effect on linolenic acid content. The percentage of variation accounted for by the models of estimation varied according to the heritability of the trait. The R² was high (up to 78%) for maturity, lodging, and vining, and low (up to 21%) for seed yield. Most of the variation was associated with the BC₂F₁ family from which the lines were derived. There was little evidence that digenic epistasis was an important source of variation.Journal Paper No. J-13505 of the Iowa Agric. Home Econ. Exp. Stn., Ames, IA, Project 2475.     

A molecular approach to combat spatio-temporal variation in insecticidal gene (<Emphasis Type="Italic">Cry1Ac</Emphasis>) expression in cotton

Spatio-temporal expression of an insecticidal gene (Cry1Ac) in pre existing transgenic lines of transgenic cotton was studied. Seasonal decline in expression of Cry1Ac differed significantly among different cotton lines tested in the field conditions. The leaves of the Bt cotton plants were found to have the highest levels of toxin expression followed by squares, bolls, anthers and petals. Expression of the gene decreased consistently with the age of plants. Toxin expression in fruiting parts was not enough to confer full resistance against bollworms. The reduction in efficacy of transgenic cotton plants late in the season was attributed to reduction in promoter activity. For this purpose, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) small subunit (rbcS) promoter was isolated from Gossypium arboreum that was further cloned upstream of an insecticidal gene (Cry1Ac) in expression vector pCAMBIA 1301. A local cotton cultivar NIAB-846 was transformed with Cry1Ac driven by rbcS promoter. The same cotton cultivar was also transformed with Cry1Ac gene driven by 35SCaMV promoter to compare the expression pattern of insecticidal gene under two different promoters. The results showed that rbcS is an efficient promoter to drive the expression of Cry1Ac gene consistent throughout the life of cotton plant as compared to 35S promoter. The use of tissue specific promoter is also useful for addressing the biosafety issues as the promoter activity is limited to green parts of plants, hence no gene expression in roots, cotton seed and other cotton products and by products.     

Reproductive growth inLolium 1. Evaluation of genetic differences within an established variety by means of a diallel cross

Summary A genetic evaluation of S23 perennial ryegrass has been made by means of a 6 × 6 diallel cross. The characters studied were those associated with seminal reproduction and included seed yield and several of its primary components.The pattern of variation between the parents indicated a mainly additive system, itema of the Hayman analysis being significant for yield and all the other characters. Maternal effects were not a constant feature, but were evident for seed yield, plant weight and spikelet numbers/inflorescence. Dominance was a prevalent feature and invariably acted in the direction of the greater expression of the character.While a high level of incompatibility was evident from the paucity of seed setting on selfing, the variation between progeny yields following open pollination gave a range from the highly acceptable levels of commercial production to very low uneconomic levels. The results indicate that improvement in seed yield is feasible by breeding even though in this variety selection pressure has tended towards a restriction of variability for essentially agronomic features.     

Combining ability for seed yield traits of Chenopodium quinoa breeding lines

For a better understanding of the inheritance of seed yield traits in Quinoa (Chenopodium quinoa) Willd., a half-diallelic crossing experiment with six diverse but uniform breeding lines was conducted. True hybrid plants were detected by means of differences in panicle colour in 14 out of the 15 crosses performed. The agronomic performance of 14 F₂ populations and six parental lines was evaluated in field trials on fertile clay soil. General and specific combining ability of the lines (GCA and SCA) were estimated. Highly significant differences in GCA effects were found between the lines for plant height at maturity, early flowering, early maturity, seed yield and thousand seed weight. Significant SCA effects were only found for plant height at maturity. However, SCA effects were rather small and accounted for 7% of the total variance. The finding of large GCA effects and low SCA effects suggests that best selection results could be expected from crosses between the agronomic best performing genotypes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Salt-tolerance in Brassica juncea L. I. In vitro selection,agronomic evaluation and genetic stability

Summary In vitro selection of salt tolerant plants of Brassica juncea L. (Indian mustard) cv. Prakash has been accomplished by screening highly morphogenic cotyledon explant cultures on high NaCl media. Out of a total of 2,620 cotyledons cultured on high salt medium, 3 survived, showed sustained growth and regenerated shoots. They were multiplied by axillary bud culture on NaCl free medium. The salt-selected shoots retained salt tolerance following 3 month of growth and multiplication on control medium. While two of these somaclones flowered and set seeds, third one grew slowly, had abnormal leaf morphology and was sterile. The seed of the two fertile plants were sown in the field to raise R₁ segregating generation. Data were recorded for field, other agronomic components and oil content. The somaclonal lines, both selected salt-tolerant and non-selected, showed tremendous amount of variation for all the characters studied. One of the two tolerant somaclones invariably showed reduced height, longer reproductive phase and higher 1000 seed weight. Based on the agronomic performance of R₁ plants of these somaclones, some plants were selected and their progeny were evaluated for agronomic performance under standard field conditions and salt-tolerance in the greenhouse using sand pot culture method. Most of the lines bred true for their specific characteristics. In the greenhouse, selected salt-tolerant somaclones (SR-2 and SR-3) performed better for plant growth, yield and other agronomic traits at higher salt treatments, indicating thereby that salt-tolerance trait selected in vitro was expressed in the whole plants and is genetically stable and transmitted onto the progeny. The two tolerant lines, however, differed in their salt-tolerance during vegetative and reproductive phases as indicated by their salt-tolerance and stress susceptibility indices. The mechanism of salt-tolerance is not clear and needs to be further investigated.     

Insect-mediated seed-set evaluation of 21 soybean lines segregating for male sterility at 10 different loci

The cowpea trypsin inhibitor gene (CpTI) and neomycin phosphotransferase gene (nptII) were introduced into the embryonic callus cells of immature embryos of wheat elite line Shannong 995604 using Agrobacterium-mediated gene transfer. Independent plantlets were regenerated from kanamycin-resistant calli. PCR and real time PCR analysis, PCR-Southern and Southern blot hybridization indicated that there were three independently-dervied transgenic plants viz. transformed-I, II and III (T-I, T-II and T-III). The segregation of CpTI in the transgenic wheat progenies of T-Iand T-III were consistent with Mendelian inheritance. Resistance to the storage insect pest of wheat viz. the grain moth (Sitotroga cerealella Olivier) was improved significantly in seeds of the three transgenic wheat T₂ lines obtained from T₁ PCR-positive plants. The frequency of moth-eaten seed from T-I, T-IIand T-III was reduced 66.76%, 62.48% and 43.59% respectively. The investigation of agronomic traits of the three transgenic wheat T₁ PCR-positive plants revealed that the three transgenic lines had excellent agronomic traits. They provide good germplasm resource for wheat genetic improvement.     

A chlorophyll-reduced seedling mutant in oilseed rape, Brassica napus, for utilization in F1 hybrid production

A mutant chlorophyll‐reduced (Cr) seedling with yellow‐green cotyledons and leaves was obtained from the Brassica napus inbred line 3529 induced by fast neutron and diethyl sulphate (DES). Genetic analysis revealed that the Cr seedling marker trait was controlled by a pair of recessive genes. A randomized complete block design was used to evaluate its agronomic performance. Results from 2 years of tests indicated that the seed yield of Cr lines was significantly lower than that of normal green plants; however, when the Cr gene was in the heterozygous condition, no deleterious effects on yield characteristics and disease resistance were observed. The Cr seedling marker trait was introduced into male‐sterile lines, and Cr male‐sterile lines revealed the same superior combining ability as normal chlorophyll (Nc) lines. The Cr trait can therefore be used as a marker to produce hybrid seed.     

Variation for agronomic characteristics in Crambe hispanica, a wild relative of Crambe abyssinica

Summary In order to assess the potential of Crambe hispanica, either in breeding programmes of C. abyssinica or as an oilseed crop in itself, 36 accessions of C. hispanica (29 of var. hispanica and 7 of var. glabrata) were grown in a greenhouse and evaluated for morphological characteristics, earliness, plant habit, seed characteristics and fatty acid composition. Four lines of C. abyssinica were included for reference. The 29 accessions of var. hispanica showed significant variation for all observed characteristics. Besides morphological characteristics, large variation was found for earliness, number of primary branches, seed yield, 1000 seed weight and volume, and linoleic, linolenic and erucic acid content. Morphological characteristics, earliness and plant habit did not show any high correlations with seed characteristics or fatty acid composition, except for seed hull (pericarp) mottling, which was related to a high oil and erucic acid content. The seven accessions of var. glabrata showed little variation. The large genetic variation in combination with promising figures for several characteristics, found in C. hispanica, may be useful in breeding programmes of the oilseed crop C. abyssinica, for which the available genetic variation is limited. Prospects of selection for high-erucic acid genotypes are discussed. Compared to C. abyssinica, both botanical varieties of C. hispanica are characterized by a cordate shape of the basal leaves, lack of seed retention and a lower DNA content. Plants of var. glabrata differed from var. hispanica in a sparsely hispid upper leaf surface and round stems and branches covered with a waxy layer. These clear differences and lack of success in intercrossing both varieties of C. hispanica strongly suggest that their taxonomic classification should be reconsidered.     

Agronomic Traits and Chromosome Behavior of Autotetraploid Sorghums

The agronomic performance and chromosome behavior of autotetraploid sorghum [Sorghum bicolor (L.) Moench] inbreds and F₁ hybrids were investigated. Autotetraploids have possible commercial use and can serve as bridging species in crosses to natural tetraploids. Autotetraploid sorghum inbreds (2n = 40) had higher kernel weight, seed yield, and protein and amino acid content than their diploid counterparts. Stalk height and panicle length of the autotet-raploids, however, were not different from those of the diploids, and seed set of autotetraploids was lower in early generations. Seed set of autotetraploid Ft hybrids was related to and higher than that of the autotetraploid parental inbred lines. Frequency of quadrivalents, anaphase I and II laggards, and quartet micronuclei varied among autotetraploids. Frequency of quadrivalents did not appear to be an important factor in seed set nor was it significantly associated with frequency of laggards. Aneuploids (2n = 39, 41) had higher percentages of laggards and micronuclei than did euploids (2n = 40). Methods of pollination significantly affected seed set in autotetraploid S4 lines. Differences in seed set among autotetraploid lines indicated the feasibility of selecting for lines with high seed set and utilizing those lines for hybrid production.     

Selection for resistance to Septoria nodorum in wheat

Summary A population of 572 F₂ derived F₃ lines from six crosses were used to estimate parameters relevant to selection for resistance to Septoria nodorum of wheat. Lines were grown in disease free (fungicide sprayed) and inoculated microplots in 2 replications of a split-plot design in a single environment in 1977. Average yield reduction due to disease was approximately 50%; this was associated with an average septoria score of 50% on the flag leaf, an average septoria score of 42% on the head, and a reduction of 37% in seed weight. Low S. nodorum scores were correlated with late heading date, tall plant height, high grain yield, and high seed weight in diseased plots, and high seed weight % (seed weight in diseased plots expressed as a percentage of seed weight in fungicide sprayed plots).Restricted selection indexes were used to study the relative contributions of disease escape, true resistance, and tolerance to variability in grain yield in diseased plots, seed weight in diseased plots, and seed weight %. True resistance appeared to be the most important factor causing variation in grain yield in diseased plots and seed weight %. Tolerance and escape seemed to be more important for seed weight in diseased plots.Heritabilities of S. nodorum scores on the flag leaf and head were 63% and 52%, respectively. Leaf and head scores could be used most effectively as selection criteria to upgrade resistance in a population before harvest.Selection for high seed weight % slightly reduced yields in disease free plots, although yield in diseased plots and seed weight in diseased plots were increased. However, selection for increased yield or increased seed weight in diseased plots improved yield in disease free plots. It is suggested that direct selection for yield or seed weight in diseased plots is likely to achieve more desirable goals than selection for seed weight %.