Genetic dissection of thousand-seed weight in linseed (Linum usitatissimum L.) using multi-locus genome-wide association study

Flaxseed/linseed is an important oilseed crop having applications in the food, nutraceutical, and paint industry. Seed weight is one of the most crucial determinants of seed yield in linseed. Here, quantitative trait nucleotides (QTNs) associated with thousand-seed weight (TSW) have been identified using multi-locus genome-wide association study (ML-GWAS). Field evaluation was carried out in five environments in multi-year-location trials. SNP genotyping information of the AM panel of 131 accessions comprising 68,925 SNPs was employed for ML-GWAS. From the six ML-GWAS methods employed, five methods helped identify a total of 84 unique significant QTNs for TSW. QTNs identified in ≥ 2 methods/environments were designated as stable QTNs. Accordingly, 30 stable QTNs have been identified for TSW accounting up to 38.65% trait variation. Alleles with positive effect on trait were analyzed for 12 strong QTNs with r2 ≥ 10.00%, which showed significant association of specific alleles with higher trait value in three or more environments. A total of 23 candidate genes have been identified for TSW, which included B3 domain-containing transcription factor, SUMO-activating enzyme, protein SCARECROW, shaggy-related protein kinase/BIN2, ANTIAUXIN-RESISTANT 3, RING-type E3 ubiquitin transferase E4, auxin response factors, WRKY transcription factor, and CBS domain-containing protein. In silico expression analysis of candidate genes was performed to validate their possible role in different stages of seed development process. The results from this study provide significant insight and elevate our understanding on genetic architecture of TSW trait in linseed

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Not AvailableStudies on early-season and mid-season cold temperature stress on growth and yield components in diverse classes of winter sorghum are essential for targeting hybrid development that is otherwise confined only to rainy season-grown sorghum. The results showed that from among the 194 winter sorghum genotypes belonging to 5 groups – varieties, B-lines, R-lines, hybrids and germplasm lines, 81% of the genotypes were correctly placed in their respective groups based on discriminant analysis. Principal component analysis showed that most of the traits involved in the study are important and variability cannot be explained by a few traits and the traits recorded at seedling and maturity stages were explained by different principal components. Most of the traits recorded under cold stress at seedling stage did not correlate with those recorded under cold stress at anthesis. There is scope for improvement of individual groups for seedling dry fodder yield and grain yield, more so in the case of hybrids and female parental lines. Breeding for cold tolerance at seedling as well as anthesis stages has to be separately targeted. Thus, for developing new winter sorghum hybrids, female parental lines have to be diversified and improved for grain yield and percentage of seed set by crossing with promising germplasm lines identified in the study.Not Availabl

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Not AvailableFoxtail millet is one of the climate resilient crops having great capabilities to sustain agriculture production in near future. Forty four genotypes of foxtail millet were evaluated to study the genetic variability, correlation and path coefficients. The Estimates of genotypic and phenotypic coefficients of variation were high for number of productive tillers plant-1, number of panicles plant-1, grain yield plant-1, straw yield plant-1 and iron content. All the traits except plant height had the maximum heritability. High genetic advance as per cent of mean coupled with high estimates of broad sense heritability (h2 b) (>60%) indicated that, the variation observed for most of the traits were heritable and selection would be effective for improvement of these traits. Grain yield plant-1 (g) was highly significant and positively correlated with number of productive tillers plant-1, panicle length, number of panicles plant-1, 1000-grain weight, straw yield plant-1 and protein content. The selection in positive direction for these traits with grain yield plant-1 (g) can be practiced for genetic enhancement of grain yield. Path coefficient analysis revealed that 1000-grain weight had the highest positive direct effects on grain yield plant-1. The indirect effect of number of panicles, panicle length (cm), number of productive tillers and straw yield through 1000-grain weight was positive and moderate to high indicating the direct selection for 1000-grain weight in foxtail millet will lead to simultaneous indirect selection of these traits for increased grain yield plant-1.Not Availabl

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Not AvailableSorghum [Sorghum bicolor (L.) Moench] is a drought-resilient crop, grown extensively in semiarid tropics of the world. To understand the scenario of sorghum cultivation across the world, trends in area and yield gain and associated changes in yield stability were analyzed in the top 10 sorghum-producing countries from 1970 to 2009. Asian countries and the United States recorded a large drop in harvested area. Grain yield levels increased substantially in all the countries except Sudan. Relative to yield level of 1970, sorghum productivity increased annually at 0.96% yr−1 across the top 10 countries analyzed. China (100.9 kg ha−1 yr−1) and Nigeria (48.6 kg ha−1 yr−1) experienced phenomenal yield gain before reaching a plateau. Overall yield gain was not associated with increased yield stability in a majority of countries except Ethiopia. In fact, in China and India (post-rainyseason sorghum), the yield variability increased over time. Genetic gain for grain yield over years in the Indian sorghum improvement program was prominent in rainy-season hybrid trials (18.5 kg ha−1 yr−1), whereas both in post-rainyseason hybrid and varietal trials it was insignificant. Much progress in rainy-season variety trials after 1985 was not observed. Across years in India, the gap between potential and farm yield declined 0.32% yr−1 among rainy-season cultivars and 0.46% yr−1 among post-rainy-season cultivars. The analysis reveals that though substantial progress has been made towards yield gain, this was not represented by increased production because of extensive loss of the sorghum area to other remunerative crops.Not Availabl

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Not AvailableKnowledge on genetic diversity is necessary to determine the relationships among the genotypes, which allow the selection of individual accessions for crop breeding programmes. The present study aimed at assessing the extent and pattern of genetic diversity within a set of 251 sorghum genotypes using SSR markers. A total of 393 alleles were detected from the 251 genotypes, with the number of alleles ranging from 2 (Xcup11) to 24 (Sb5-206) and an average of 10.07 alleles per primer pair. Pairwise Wright’s FST statistic and Nei’s genetic distance estimates revealed that the race and geographical origin were responsible for the pattern of diversity and structure in the genetic materials. In addition, the analysis also revealed high genetic differentiation between the rainy and post-rainy sorghum groups. Narrow diversity was observed among the different working groups in the rainy (restorers and varieties) and post-rainy (varieties and advanced breeding lines) sorghum groups. Neighbour-joining and STRUCTURE analysis also classified 44 elite lines broadly into two distinct groups (rainy and post-rainy). However, limited diversity within the rainy and post-rainy sorghum groups warranted an urgent need for the utilization of diverse germplasm accessions for broadening the genetic base of the Indian breeding programme. The diverse germplasm accessions identified from the mini-core accessions for utilization in breeding programmes are discussed.Partial financial assistance by NAIP project on ‘Bioprospecting of genes and allele mining for abiotic stress toleranc

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Not AvailableSorghum [Sorghum bicolor (L.) Moench] is a drought-resilient crop, grown extensively in semiarid tropics of the world. To understand the scenario of sorghum cultivation across the world, trends in area and yield gain and associated changes in yield stability were analyzed in the top 10 sorghum-producing countries from 1970 to 2009. Asian countries and the United States recorded a large drop in harvested area. Grain yield levels increased substantially in all the countries except Sudan. Relative to yield level of 1970, sorghum productivity increased annually at 0.96% yr−1 across the top 10 countries analyzed. China (100.9 kg ha−1 yr−1) and Nigeria (48.6 kg ha−1 yr−1) experienced phenomenal yield gain before reaching a plateau. Overall yield gain was not associated with increased yield stability in a majority of countries except Ethiopia. In fact, in China and India (post-rainyseason sorghum), the yield variability increased over time. Genetic gain for grain yield over years in the Indian sorghum improvement program was prominent in rainy-season hybrid trials (18.5 kg ha−1 yr−1), whereas both in post-rainyseason hybrid and varietal trials it was insignificant. Much progress in rainy-season variety trials after 1985 was not observed. Across years in India, the gap between potential and farm yield declined 0.32% yr−1 among rainy-season cultivars and 0.46% yr−1 among post-rainy-season cultivars. The analysis reveals that though substantial progress has been made towards yield gain, this was not represented by increased production because of extensive loss of the sorghum area to other remunerative cropsNot Availabl

Genetic Diversity and Population Structure Analysis to Construct a Core Collection from Safflower (<i>Carthamus tinctorius</i> L.) Germplasm through SSR Markers

Genetic resources are the fundamental source of diversity available to plant breeders for the improvement of desired traits. However, a large germplasm set is difficult to preserve and use as a working collection in genetic studies. Hence, the present study evaluates the genetic diversity of 3115 safflower accessions from the Indian National Gene Bank, including Indian cultivars, to develop a manageable set of accessions, with similar genetic variations of germplasm studied. A total of 18 polymorphic SSR markers were used. The genetic diversity analysis revealed that germplasm accessions were highly diverse and there is no correlation between genetic diversity and the geographical collection of germplasm or sourcing of germplasm. A core set was developed using a core hunter software with different levels of composition, and it was found that 10% of the accessions showed maximum gene diversity and represented an equal number of alleles and major allele frequency in the germplasm studied. The developed core consisted of 351 accessions, including Indian cultivars, and they were validated with various genetic parameters to ascertain that they were a true core set for the studied accessions of safflower germplasm