Showing papers on "Plant breeding published in 2011"

Towards F1 Hybrid Seed Potato Breeding

Abstract: Compared to other major food crops, progress in potato yield as the result of breeding efforts is very slow. Genetic gains cannot be fixed in potato due to obligatory out-breeding. Overcoming inbreeding depression using diploid self-compatible clones should enable to replace the current method of out-breeding and clonal propagation into an F1 hybrid system with true seeds. This idea is not new, but has long been considered unrealistic. Severe inbreeding depression and self-incompatibility in diploid germplasm have hitherto blocked the development of inbred lines. Back-crossing with a homozygous progenitor with the Sli gene which inhibits gametophytic self-incompatibility gave self-compatible offspring from elite material from our diploid breeding programme. We demonstrate that homozygous fixation of donor alleles is possible, with simultaneous improvement of tuber shape and tuber size grading of the recipient inbred line. These results provide proof of principle for F1 hybrid potato breeding. The technical and economic perspectives are unprecedented as these will enable the development of new products with combinations of useful traits for all stakeholders in the potato chain. In addition, the hybrid’s seeds are produced by crossings, rendering the production and voluminous transport of potato seed tubers redundant as it can be replaced by direct sowing or the use of healthy mini-tubers, raised in greenhouses.

Gametic embryogenesis and haploid technology as valuable support to plant breeding

Abstract: Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced management techniques (pest and disease control, fertilization, and irrigation). Biotechnologies provide powerful tools for plant breeding, and among these ones, tissue culture, particularly haploid and doubled haploid technology, can effectively help to select superior plants. In fact, haploids (Hs), which are plants with gametophytic chromosome number, and doubled haploids (DHs), which are haploids that have undergone chromosome duplication, represent a particularly attractive biotechnological method to accelerate plant breeding. Currently, haploid technology, making possible through gametic embryogenesis the single-step development of complete homozygous lines from heterozygous parents, has already had a huge impact on agricultural systems of many agronomically important crops, representing an integral part in their improvement programmes. The aim of this review was to provide some background, recent advances, and future prospective on the employment of haploid technology through gametic embryogenesis as a powerful tool to support plant breeding.

Developing rice with high yield under phosphorus deficiency: Pup1 Sequence to Application

Abstract: The major quantitative trait locus (QTL) Phosphorus uptake1 (Pup1) confers tolerance of phosphorus deficiency in soil and is currently one of the most promising QTLs for the development of tolerant rice (Oryza sativa) varieties. To facilitate targeted introgression of Pup1 into intolerant varieties, the gene models predicted in the Pup1 region in the donor variety Kasalath were used to develop gene-based molecular markers that are evenly distributed over the fine-mapped 278-kb QTL region. To validate the gene models and optimize the markers, gene expression analyses and partial allelic sequencing were conducted. The markers were tested in more than 80 diverse rice accessions revealing three main groups with different Pup1 allele constitution. Accessions with tolerant (group I) and intolerant (group III) Pup1 alleles were distinguished from genotypes with Kasalath alleles at some of the analyzed loci (partial Pup1; group II). A germplasm survey additionally confirmed earlier data showing that Pup1 is largely absent from irrigated rice varieties but conserved in varieties and breeding lines adapted to drought-prone environments. A core set of Pup1 markers has been defined, and sequence polymorphisms suitable for single-nucleotide polymorphism marker development for high-throughput genotyping were identified. Following a marker-assisted backcrossing approach, Pup1 was introgressed into two irrigated rice varieties and three Indonesian upland varieties. First phenotypic evaluations of the introgression lines suggest that Pup1 is effective in different genetic backgrounds and environments and that it has the potential to significantly enhance grain yield under field conditions.

Genetic diversity of wheat (Triticum aestivum L.) genotypes based on cluster and principal component analyses for breeding strategies

Abstract: Determination of genetic diversity is useful for plant breeding and hence production of more efficient plant species under different conditions. Accordingly, the most common wheat (Triticum aestivum L.) genotypes including 36 winter wheat genotypes cultivated in different regions of Iran were selected, grown and analyzed for genetic diversity. The experiment was conducted at the Agricultural Research Farm of Shahed University, Tehran, Iran as a randomized complete block design with three replications. All traits, except emergence time and heading time were statistically significant among different genotypes. Cluster analysis based on squared Euclidean distance and ward's method, categorized the cultivars into seven groups. The highest genetic distance was observed between Sardari and Spn/Mcd/Cama/3/Nzr/4/Passarinho (SP) genotypes. Based on Principal Component Analysis (PCA), the first five components explained over 97% of genetic variation. Cluster analysis based on PCA using the first five principal components indicated six separate groups of genotypes, with the maximum genetic distance observed between Sardari and Vorona/Kauz (VO) genotypes. Such differences in genetic component of traits studied in this manuscript can be applied as a new source of variation in other breeding programs and crossing nurseries for wheat improvement.

Stacked herbicide tolerance event 8264.44.06.1, related transgenic soybean lines, and detection thereof

Abstract: This invention relates in part to soybean event pDAB8264.44.06.1 and includes a novel expression cassettes and transgenic inserts comprising multiple traits conferring resistance to glyphosate, aryloxyalkanoate, and glufosinate herbicides. This invention also relates in part to methods of controlling resistant weeds, plant breeding and herbicide tolerant plants. In some embodiments, the event sequence can be "stacked" with other traits, including, for example, other herbicide tolerance gene(s) and/or insect-inhibitory proteins. This invention further relates in part to endpoint TaqMan PCR assays for the detection of Event pDAB8264.44.06.1 in soybeans and related plant material. Some embodiments can perform high throughput zygosity analysis of plant material and other embodiments can be used to uniquely identify the zygosity of and breed soybean lines comprising the event of the subject invention. Kits and conditions useful in conducting these assays are also provided.

Genetic variability, heritability and trait associations in durum wheat (Triticum turgidum L. var. durum) genotypes

Abstract: Information on the extent of genetic variability and heritability as well as correlation among agronomically important traits is a requirement to design a suitable plant breeding method. The present research was conducted at Sinana, Southeastern Ethiopia during the 2009 main crop growing season. The experimental material consisted of 16 durum wheat genotypes tested in a randomized complete block design with three replications. Twelve agronomic traits were included in the investigation. Highly significant differences were revealed among durum wheat genotypes for all traits studied, suggesting the possibility of improving durum wheat for these traits. Plant height and number of kernels per spike showed the highest phenotypic and genotypic coefficients of variations and genetic advance, whereas, days to maturity and test weight had the lowest values. Plant height exhibited highest heritability value of 98.3% while number of spikelets per spike showed minimum value of 36.4%. The genotypic correlations estimated showed positive association of grain yield with days for heading (r=0.50), harvest index (r=0.69) and kernels number per spike (r=0.81). Harvest index (1.13) and biomass (0.81) exhibited the highest positive and significant direct effect on grain yield. Hence, these traits could be considered as suitable selection criteria for the development of high yielding durum wheat varieties. Key words: Correlation coefficient, durum wheat, genetic advance, heritability, path coefficient.

Biology and breeding of food legumes.

Abstract: 1 History, Origin and Evolution 2 Biology and Floral Morphology 3 Domestication 4 Breeding for Improvement of Cool Season Food Legumes 5 Breeding for Improvement of Warm-season Food Legumes 6 Distant Hybridization and Alien Gene Introgression 7 Polyploidy 8 Cytology and Molecular Cytogenetics 9 Molecular Cytogenetics in Physical Mapping of Alien Introgressions 10 In vitro techniques 11 Microsporogenesis and Haploidy Breeding 12 Genetic Transformation 13 Male Sterility and Hybrid Production Technology 14 Mutagenesis 15 Breeding for Biotic Stresses 16 Breeding for Abiotic Stresses 17 Legume Improvement in the Acidic and less Fertile Soils 18 Genomic Approaches for Management of Abiotic Stresses 19 Molecular Breeding and Marker-assisted Selection 20 Underutilized Food Legumes 21 Legumes as a Model Plant Family 22 Plant Genetic Resources and Conservation of Biodiversity 23 Seed Dormancy and Viability 24 Post Harvest Technology 25 Value Addition and Trade

Association Mapping of Biomass Yield and Stem Composition in a Tetraploid Alfalfa Breeding Population

Abstract: Alfalfa (Medicago sativa L.), an important forage crop that is also a potential biofuel crop, has advantages of high yield, high lignocellulose concentration in stems, and has low input costs. In this study, we investigated population structure and linkage disequilibrium (LD) patterns in a tetraploid alfalfa breeding population using genome-wide simple sequence repeat (SSR) markers and identified markers related to yield and cell wall composition by association mapping. No obvious population structure was found in our alfalfa breeding population, which could be due to the relatively narrow genetic base of the founders and/or due to two generations of random mating. We found significant LD ( p 10%) alleles across the 71 SSR markers, 15 showed strong association (p < 0.005) with yield in at least one of five environments, and most of the 15 alleles were identified in multiple environments. Only one allele showed strong association with acid detergent fiber (ADF) and one allele with acid detergent lignin (ADL). Alleles associated with traits could be directly applied in a breeding program using marker-assisted selection. However, based on our estimated LD level, we would need about 1000 markers to explore the whole alfalfa genome for association between markers and traits.

Genetic Variability, Diversity and Association of Quantitative Traits with Grain Yield in Rice ( Oryza sativa L.)

Abstract: Context: Genetic diversity is pre-requisite for any crop improvement programme as it helps in the development of superior recombinants. Objectives: Recognizing the importance of genetic diversity in plant breeding experiments, the present research work was taken up to estimate genetic diversity in different accessions of rice for various agro-economically important characters. Materials and Methods: Experiments were carried out with 40 Rice ( Oryza sativa L.) genotypes which were evaluated for yield and yield contributing traits in Kharif-2007-08. The data were recorded on 10 randomly selected plants from each replication for 12 quantitative characters studied. However days to 50% flowering was recorded on per plot basis. Mean values were subjected to analysis of variance to test the significance for each character. The genetic divergence was estimated and the grouping of the genotypes into cluster was done. Results: Sufficient amount of variability was found in the entire gene pool for all traits studied. The higher magnitude of genotypic and phenotypic coefficients of variation was recorded for plant height, grain yield per hill, harvest index and biological yield per hill. High heritability along with high genetic advance as percent of mean was registered for harvest index, grain yield, plant height, biological yield, test weight, number of tillers per hill and number of spikelets per panicle suggesting preponderance of additive gene action in the expression of these characters. On the basis of Mahalanobis D2 statistics the genotypes were grouped into seven clusters. Plant height, biological yield and test weight contributed considerably, accounting for 86.16 % of total divergence. The genotypes superior in some clusters may be involve in a multiple crossing programme to recover transgressive segregants with high genetic yield potential and early maturity. Conclusion: The promising genotypes selected from diverse clusters should be involved in the hybridization programme in order to transfer some of the desirable yield contributing characters consisted by them. Key words: Rice ( Oryza sativa ); genetic variability; diversity; clustering pattern DOI: 10.3329/jbs.v17i0.7110 J. bio-sci. 17: 77-82, 2009

Drought Resistance and Its Improvement

Abstract: Plant breeding has been successful in developing drought resistant crop cultivars. However the traditional breeding method by using yield as a selection index and performing multi-environmental yield trials has been costly and slow. Plant physiology is now incorporated into the breeding program by using physiological selection criteria relevant to the designated plant ideotype and subsequent plant performance in the target stress environment. Genomics offer a great potential for the improvement of breeding efficiency towards water limited environments. There are still inherent problems in deploying marker assisted selection and transgenic technology into breeding program for drought resistance. The potential of genomics can be realized only when it will be well synchronized with plant breeding concept, theory and methods.

Physiological attributes associated with yield and stability in selected lines of a durum wheat population.

Abstract: Further increasing yield potential remains one of the main objectives of wheat breeding, even in stressful environments. In general, past genetic gains were associated with increases in harvest index, and future gains should be related to greater biomass. Identifying genetic sources for such improvement may be relevant. Researchers of TRITIMED identified DH lines of durum wheat apparently possessing not only high yield potential but also good yield stability. We aimed to determine physiological attributes responsible for yield and stability among a set of genotypes derived from two parents (Cham 1 and Lahn) and four of the most promising lines of the DH population (2401, 2408, 2410, 2517). Seven field trials were carried out within the Mediterranean agricultural region of the Ebro Valley, under a wide range of conditions (ca 2–10 mg ha−1). In four of these experiments, sub-plots were included with source-sink manipulations imposed after anthesis. Cham 1, a cultivar known for high yields in semi-arid conditions, showed the highest yield potential. Although it showed less yield stability than Lahn, even under the lowest yielding conditions its yield was not significantly lower than that of Lahn. RILs 2408, 2410, 2004 and 2517 slightly outyielded Lahn in high-yielding conditions, but under poorer environments they tended to yield less. Interestingly, yield differences were closely related to their biomass rather than harvest index. Thus yield differences relating to the number of grains per m2 were due to differences in spike dry matter at anthesis, reflecting in part genotypic differences in crop growth from jointing to anthesis. In general grain weight did not respond to spike trimming after anthesis, although in two experiments the grain weight of Cham 1 did so. Thus, even the highest-yielding cultivar possessed grains that overall seemed more limited by its constitutive capacity to grow than by the availability of resources to reach this capacity (though occasionally they may be co-limited). Overall, the most interesting feature was the empirical evidence that improvement of biomass within elite material is a worthwhile objective.

Evolution of plant breeding

Abstract: Plant breeding is considered one of the longest ongoing activities undertaken by humans, who select plants more productive and useful to themselves and the animals for at least 10,000 years ago. The evolution of civilizations paralleled the success of plant breeding, although this has not been recognized by the public. The reason may be lack of understanding of what plant breeding encompasses. The concept of plant breeding evolved, depending on the time it was formulated, but without losing the essence of being art and science of manipulating plants for man. This review discusses the evolution of the concepts and the methods of plant breeding, here divided arbitrarily into selection based on phenotypes, breeding values and genotypes. No matter how big the pool of genetic information in recent years, the phenotype will continues to be important in the present and future.

Current Situation and Suggestions for Development of Two-Line Hybrid Rice in China

Abstract: Great progress has made in Two-line hybrid rice breeding in China.Up to 2010,a total of 427 two-line hybrid combinations were registered in China.Among them,62 were nationally registered and titled as "super rice" by the Ministry of Agriculture,China.From 1993 to 2009,there were 121 combinations with the planting area over 6 700 hm2,and the total planting area reached 20.974 million hm2.With the planting area of 8.25×105 hm2 in 2002,Liangyoupeijiu ranked first among all hybrid combinations in planting area.In the following 7 years,two-line hybrid combination ranked first for 6 years,and second for one year.In recent years,two-line hybrid rice has become an important type in rice production in China,accounting for about 20% of the total planting area of hybrid rice.The current situation of the development of two-line hybrid rice was introduced,the main problems were discussed and the suggestions were proposed.

Heritability and correlations among food-grade traits in soybean

Abstract: With 5 tables Abstract Societal changes towards healthier food have helped uncover the nutritional value and health benefits of soybeans. Hence, the development of food-grade specialty cultivars has become a niche market for soybean breeders and producers. The objectives of this study were to estimate the heritability and correlations among five food-grade traits: seed size, protein, sucrose, raffinose, and stachyose concentration. We evaluated 98 recombinant inbred lines derived from a cross between a high protein line and a large-seeded cultivar with moderate sucrose concentration at two locations in Arkansas for 2 years. Although food-grade traits were significantly affected by year and location interactions, larger variability was attributed to differences among lines than to the line by location interaction for seed size, protein, sucrose and stachyose. Heritability estimates ranged from 0.46 to 0.86, so selection for genotypes with specific combination of these traits should be reliable. Because of a negative correlation (−0.68), selection for high sucrose will likely be accompanied by a reduction in protein. Our findings will help breeders develop efficient strategies for breeding food-grade soybean cultivars.

The use of conjoint analysis to determine the relative importance of specific traits as selection criteria for the improvement of perennial pasture species in Australia

Abstract: Despite the large number of active programs breeding improved forage plants, relatively little is known about the weightings that breeders consciously or subconsciously give to specific traits when selecting individual plants or that agronomists and producers use when assessing the relative merits of contrasting cultivars. This is in contrast to most modern animal breeding programs where the relative merits of novel genetics may be assessed against an index-based breeding objective. These technologies have not been widely used in crop or forage plant breeding but their use in forest tree breeding is relatively common. We have assessed the usefulness of discrete choice experiment techniques in the development of weightings for specific traits in forage plant improvement based on the views of an expert panel (plant breeders and non-breeders – agronomists, nutritionists, senior managers in breeding companies and consultants) asked to consider the requirements in four species (white clover, lucerne, perennial ryegrass and tall fescue). The results indicate that criteria related to abiotic stress tolerance, adaptation or the costs of pasture (root growth, drought tolerance, persistence, resistance to invertebrate pests, tolerance of hostile soil conditions) were deemed to be particularly important for white clover, while the highest-rated criteria for lucerne were not dissimilar, being tolerance of hostile soil conditions, persistence and tolerance of transient water-logging. For perennial ryegrass, three of the five highest-weighted criteria (drought tolerance, root growth, rate of recovery of pasture after water) are related to yield in environments where too much or too little water is a problem, highlighting the importance that the experts placed on the ability of the plant to withstand this important abiotic stress. For tall fescue, the highest-rated criteria were seedling vigour, drought tolerance, and persistence. Overall the preference weightings tended to reflect the perceived limitations of the various species, such as the priority of seedling vigour in tall fescue. This focus on the importance of abiotic stress is especially interesting as previous attempts to identify priorities have focused on the forage quality traits rather than analysing their importance relative to traits related to herbage yield or stress tolerance. This study highlights the importance of further work to help determine the focus of breeding objectives and selection criteria for different pasture species across production systems.

Drought Tolerance of Several Tomato Genotypes Under Greenhouse Conditions

Abstract: Growth and production of agricultural crops are greatly affected by water shortage. Thus, yield enhancement under drought conditions is a major goal of plant breeding. Four commercial tomato cultivars (Imperial, Pakmore VF, Strain-B and Tnshet Star), a drought-tolerant breeding line (L 03306) and their hybrid combinations were selected in this study to evaluate drought tolerance and to develop initial material for a drought tolerance breeding program. Four-weeks-old seedlings were transplanted into soil under greenhouse conditions. Six irrigation treatments (T = 20, T = 40, T = 60, T = 80, T (control) = 100 and T = 120% of the 12345 6 estimated evapotranspiration, ET ) were imposed during a 140-day growing period through a drip irrigation c system. Vegetative growth, flowering and yield traits were measured while water use efficiency (WUE) was determined. All vegetative and fruit traits decreased significantly as deficit irrigation levels increased. For T1 and T , yield was reduced by 46.7 and 33.5%, respectively, compared with T. WUE was increased significantly 25 as the amount of irrigation water decreased. The relationship between production and water amount was a second-degree polynomial. Significant differences among genotypes were found for all traits, suggesting that they could be taken into account when selecting for drought tolerance. Pakmore VF and the breeding line L 03306 had good yield performance under different deficit irrigation treatments. These genotypes could be selected for in a breeding program as recurrent (female) and donor (male) parents, respectively.

Relative efficiency of the maize- and Imperata cylindrica-mediated chromosome elimination approaches for induction of haploids of wheat-rye derivatives

Abstract: With 1 table Abstract Backcrosses were attempted of F1 hybrids of spring wheat genotypes (HS 375 and C 306) and winter wheat genotypes (Saptdhara and Tyari) with the Indian rye (Secale cereale L.) landrace ‘Lahaul Local’. Intergeneric hybridizations using pollen of maize and Imperata cylindrica (2n = 20), a wild and weedy species, were conducted in the wheat-rye-derived backcross BC1F1 and BC1F2 generations to study the relative efficiency of the two chromosome elimination approaches in the induction of haploid plants. Although seed formation was similar with both pollen sources, the relative frequency of embryo-carrying seeds ranged from 8% to 30% with I. cylindrica, whereas with maize, no embryo-carrying seed was obtained. Comparisons of induction of haploid plants in the wheat-rye backcross derivatives showed that the wheat × I. cylindrica system was superior to the wheat × maize system and was also cost effective as it shares the flowering season with wheat in sub-temperate conditions.

Genetic variability and correlation analysis for quantitative traits in chickpea genotypes (Cicer arietinum L.)

Abstract: The present studies were conducted to the estimation of correlation for quantitative traits in chickpea (Cicer arietinum L.) in the field of the department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, during the crop season 2009 to 2010. Correlation studies showed that biomass per plant, number of pods per plant, number of secondary branches per plant, number of seeds per pod and 100-seed weight were positive and significant at genotypic level but positive and highly significant at phenotypic level. Whereas number of days taken to flowering, number of days taken to maturity, primary branches per plant, secondary branches per plant were positively correlated with the grain yield per plant at genotypic and phenotypic levels. Plant height was negative and non-significantly correlated with grain yield per plant at both genotypic and phenotypic levels. Key words: Cicer arietinum, correlation, genotypic, phenotypic, chickpea, Pakistan.

Doubled Haploids Generated through Anther Culture from Crosses of Elite Indica and Japonica Cultivars and/or Lines of Rice: Large-Scale Production, Agronomic Performance, and Molecular Characterization

Abstract: We produced 3000 doubled haploid (DH) lines through anther culture of 28 crosses involving indica and japonica rice (Oryza sativa L.) cultivars. Indica cultivars showed low anther culturability (1.2% callus induction) whereas japonica cultivars had 20-fold higher (28.1%) anther culturability. A set of 121 and 124 DH lines was used for phenotypic and molecular analysis, respectively, generated from the japonica cultivar (IR69428) × indica variety (IR64). Significant variation was observed among DH lines for agronomic traits including Zn content. However, the phenotypic variance within each DH line was comparable with the mean phenotypic variance of the parents, suggesting no variation within DH line(s). A set of 209 simple sequence repeat (SSR) markers was selected to construct a linkage map with a total genetic distance of 2148.8 cM. Simple sequence repeat analysis showed 1:1 ratio of indica and japonica alleles. Of the 209 markers, 21 showed distorted segregation and these markers are randomly located over 12 chromosomes. Homozygosity was detected for all the marker loci in 124 DH lines and 28 were heterozygote. Results show that indica cultivars are recalcitrant and genes for anther culturability are partially dominant. Molecular and phenotypic trait analysis of the DH lines showed that the origin of DHs is from pollen and these 121 DH lines are thus a valuable genetic resource in mapping quantitative trait loci (QTL) for grain Zn content and other agronomic traits. Interestingly, some of the DH lines had indica traits and high (28.3 mg kg⁻¹) grain Zn content in polished rice.

The application of n-butanol improves embryo and green plant production in anther culture of Australian wheat (Triticum aestivum L.) genotypes

Abstract: The objective of this study was to improve the production from anther culture of embryos and green plants in Australian spring wheat genotypes by testing new treatments such as n-butanol, as well as other protocol modifications. To date, the use of n-butanol to enhance embryogenesis has only been tested in two European wheat cultivars; this is the first study which demonstrates its application across a range of breeding crosses. A 5-h treatment using 0.1 or 0.2% (v/v) n-butanol following anther pretreatment on a solid mannitol medium significantly improved the production of embryos, green plants and doubled haploids in a range of Australian wheat crosses and varieties. Green plant production increased between 3- and 6-fold in the crosses Yitpi/2*Bumper, Tammarin Rock/2*Bumper and Tammarin Rock/2*Magenta. The addition of calcium (Ca) and macronutrients to the mannitol pretreatment medium also significantly improved the number of embryos and green plants in varieties and crosses, but only when used in combination with n-butanol treatment. A factorial experiment with four varieties and two treatments (n-butanol and Ca/macronutrients) revealed significant interactions between treatments and genotype. In three of the four varieties, the application of n-butanol resulted in significant increases in embryos and green plants with either pretreatment medium although the best results were obtained with Ca and macronutrients in the pretreatment medium, with 200, 193 and 52 green plants per 100 anthers obtained for Bumper, Gladius and Magenta, respectively. In the variety Fortune however, n-butanol treatment did not improve embryo or green plant production unless it was combined with Ca and macronutrients in the pretreatment medium and then there were dramatic improvements; from 0 to 27 green plants per 100 anthers.

Estimation of Variability and correlation analysis for quantitative traits in chickpea (Cicer arietinum L.)

Abstract: A study was carried out in the fields of Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan during 2010-2011. Twenty elite genotypes including three standard varieties of chickpea were evaluated for means and components of variability, heritability (h2bs), genetic advance and interrelationships for various parameters. Correlation studies showed that Genotypic and phenotypic correlations of grain yield per plant with number of secondary branches per plant, biomass per plant, number of pods per plant and number of grains per plant was positive and highly significant. Genotypic correlation of grain yield per plant with plant height was positive and significant. Genotypic and phenotypic correlations of grain yield per plant with number of days taken to maturity were negative and highly significant.

Estimation of genetic association of yield and quality traits in chickpea (Cicer arietinum L.)

Abstract: The current study was carried out in the experimental fields of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan during 2009-2010. Twenty elite genotypes, including three standard varieties of chickpea, were evaluated for means and variability components, heritability (h2bs), genetic advance and interrelationships for various parameters. The highest value of genotypic coefficient was found for the fats and heritability, for 100-seed weight. Correlation studies showed that genotypic correlation of grain yield per plant with carbohydrates, proteins, 100-seed weight, moisture contents, number of pods per plant and number of seeds per pod was positive and highly significant. These traits can be used for the selection of high yielding chickpea genotypes

Genetic variation in degradability of wheat straw and potential for improvement through plant breeding.

Abstract: The degradability of cereal straw is of importance when it is used for animal feed, biological means of bioenergy production such as bioethanol production and when it is incorporated in soil. We examined wheat straw from 106 different winter wheat cultivars representing the northwest European contemporary gene pool. The cultivars were grown at two different locations to assess the potential for breeding for improved degradability. The straws exhibited much variation in degradability ranging from 258 g kg −1 to 407 g kg −1 of dry matter. The heritability for degradability was estimated to 29% indicating a reasonable potential for response to selection. Inclusion of height as a regression-term, indicated that only a minor part of genetic differences are directly related to plant height and that improvements in degradability may be achieved without unacceptable changes in straw length. Finally, a lack of correlation between degradability and grain yield indicated that straw degradability may be improved through breeding without serious negative effect on grain yield.