Flowering time is a critical stage for crop development as it regulates the ability of plants to adapt to an environment. To understand the genetic control of flowering time, a genome-wide association study (GWAS) was conducted to identify the genomic regions associated with the control of this trait in durum wheat (Triticum durum Desf.). A total of 96 landraces and 288 modern lines were evaluated for days to heading, growing degree days, and accumulated day length at flowering across 13 environments spread across Morocco, Lebanon, Mauritania, and Senegal. These environments were grouped into four pheno-environments based on temperature, day length, and other climatic variables. Genotyping with a 35K Axiom array generated 7652 polymorphic single nucleotide polymorphisms (SNPs) in addition to 3 KASP markers associated with known flowering genes. In total, 32 significant QTLs were identified in both landraces and modern lines. Some QTLs had a strong association with already known regulatory photoperiod genes, Ppd-A and Ppd-B, and vernalization genes Vrn-A1 and VrnA7. However, these loci explained only 5% to 20% of variance for days to heading. Seven QTLs overlapped between the two germplasm groups in which Q.ICD.Eps-03 and Q.ICD.Vrn-15 consistently affected flowering time in all the pheno-environments, while Q.ICD.Eps-09 and Q.ICD.Ppd-10 were significant only in two pheno-environments and the combined analysis across all environments. These results help clarify the genetic mechanism controlling flowering time in durum wheat and show some clear distinctions to what is known for common wheat (Triticum aestivum L.).
Grass pea (Lathyrus sativus L.) is an important food legume crop but notorious for plant neurotoxin β-N-Oxalyl-L-α, β-diaminopropionic acid (β-ODAP), causing neurolathyrism to human and animals. The study aimed to compare changes in physical and chemical parameters of 13 genotypes of different geographic origins in pre & post-boiling, microwaving and autoclaving. The results showed significantly different effects of pre and post-cooking treatments on genotypes and cooking methods independent of one another. The genotypes from South Asia exhibited higher β-ODAP content compared to the genotypes from other region. Significantly negative correlation was noted between protein content and β-ODAP concentration across the treatments under boiling (r = −0.555**) and microwave (r = −0.342*) treatments. Boiling was the best treatment and significantly reduced β-ODAP concentration by 70%. Its reduction percentage remained 30%, and 14% under microwaving and autoclaving, in the same order. Therefore, boiling was recommended over other treatments for safe human consumption of grass pea seeds.
ODAP (N-oxalyl-L-2,3-diaminopropionic acid) is present in the seeds of grass pea. In this study, variation of total ODAP accumulation in leaves throughout the crop growth starting from 40 days after sowing to maturity, and the distribution pattern of ODAP in different plant parts including the seeds at the mature stage was analyzed. Five grass pea accessions were evaluated for two subsequent growing seasons in one location of ICARDA, Aleppo (Syria). The results found that the rate of accumulation of total ODAP varied during plant development. Increased rates of synthesis were noticed in young leaves of grass pea. The highest total ODAP content in leaves was noted in the early growth stage (40–50 days after sowing). Mean total ODAP content in leaves ranged from 0.17 to 0.96 percent during 2010–2011 and from 0.19 to 1.28 percent during 2011–2012. During maturity, the total ODAP content was lowest in the seeds than in leaves, stems, pod cover, seed coat, and cotyledons. The ranges of total ODAP content were 0.13 (seed)–0.34 (stem), 0.20 (seed)–1.01 (leaf), 0.22 (seed)–0.62 (leaf), 0.21 (seed)–0.66 (leaf), and 0.21 (seed)–0.78 (leaf) percent in B387, B222, B390, Bio-520, and B587 accessions, respectively, during maturity. The results indicated that the rate of accumulation and synthesis of total ODAP varied during the plant lifespan. The lowest total ODAP content of leaves was observed after 130 days of sowing. The lower total ODAP content after the early vegetative stage of grass pea plants makes them suitable as a feed.
Flowering time is a critical stage for crop development as it regulates the ability of plants to adapt to an environment. To understand the genetic control of flowering time, a genome wide association study (GWAS) was conducted to identify the genomic regions associated with the control of this trait in durum wheat (Triticum durum Desf.). A total of 96 landraces and 288 modern lines were evaluated for days to heading, growing degree days, and accumulated day length at flowering across 13 environments spread across Morocco, Lebanon, Mauritania, and Senegal. These environments were grouped into four pheno-environments based on temperatures, day length and other climatic variables. Genotyping with 35K Axiom array generated 7,652 polymorphic SNPs in addition to 3 KASP markers associated to known flowering genes. In total, 34 significant QTLs were identified in both landraces and modern lines. Some QTLs had strong association with already known regulatory photoperiod genes, Ppd-A and Ppd-B and vernalization genes Vrn-A1, and Vrn3. However, these loci explained only 5 to 20% of variance for days to heading. Seven QTLs overlapped between the two germplasm groups in which Q.ICD.Eps-03 and Q.ICD.Vrn-17 consistently affected flowering time in all the pheno-environments, while Q.ICD.Eps-11 and Q.ICD.Ppd-12 were significant only in two pheno-environments and the combined analysis across all environments. These results help clarify the genetic mechanism controlling flowering time in durum wheat and show some clear distinctions to what is known for common wheat (Triticum aestivum L.)
Impact of the green revolution genes on rice and wheat productivity under rainfed environments has been debated since past few decades. Here we made an attempt to assess the impact of two major green revolution genes Rht B1 and Rht D1 on grain yield under drought stress. A total of four recombinant inbred line (RIL) populations were analyzed for this objective including PBW343 × Muu, PBW343 × Kingbird, PBW343 × Kenyaswara and Jal 95.4.3 × Kachu/Kiritati/Kachu. These populations segregated for either or both the Rht gene alleles. Our results revealed an invariable non-association of tall/ dwarf alleles of Rht B1 and Rht D1 genes with grain yield under drought stress. Tightly linked sequence tags with Rht and Vrn genes were identified for future application in wheat breeding. A genetic linkage map of 1170 DArt-seq markers covering 2870 cM was constructed in Jal 95.4.3 × Ka-chu/Kiritati/Kachu RIL population and QTLs for yield related traits were identified. Study provides an insight for researchers involved in developing the next generation climate resilient wheat varieties that can cope well with rainfed/ drought prone en-vironments.