RESUMEN
Information on the variability available in lignan and fatty acid content in the oilseed crop of Sesamum indicum has been limited. This article presents and discusses the composition, quantity, and variability available for the two traits in the sesame germplasm that are grown in diverse agro climatic regions of India. HPLC and GC analysis of sesame seeds harvested over a period of three crop seasons revealed a considerable amount of variability in lignan and fatty acids. The antioxidant lignans sesamol, sesamin and sesamolin were observed to be in the range of 0.16-3.24, 2.10-5.98 and 1.52-3.76 mg/g of seed, respectively. Similarly oleic and linoleic acids, respectively, have ranged from 34.71 to 45.61% and 38.49 to 49.60%. The black sesame seeds were found rich in sesamin, sesamolin, total lignan content and oleic acid and are thus identified nutritionally and pharmaceutically more important than white and brown seeds. Pearson statistics showed a strong correlation between the components within a particular trait and also some correlation was found between the traits. The study revealed promising cultivars for use in sesame breeding aimed at improving lignan and fatty acid contents, and can be thus directly used in human foods, nutrition, health and welfare.
RESUMEN
KEY MESSAGE: Seed weight QTL identified in different populations were synthesized into consensus QTL which were shown to harbor candidate genes by in silico mapping. Allelic variation inferred would be useful in breeding B. juncea lines with high seed weight. Seed weight is an important yield influencing trait in oilseed Brassicas and is a multigenic trait. Among the oilseed Brassicas, Brassica juncea harbors the maximum phenotypic variation wherein thousand seed weight varies from around 2.0 g to more than 7.0 g. In this study, we have undertaken quantitative trait locus/quantitative trait loci (QTL) analysis of seed weight in B. juncea using four bi-parental doubled-haploid populations. These four populations were derived from six lines (three Indian and three east European lines) with parental phenotypic values for thousand seed weight ranging from 2.0 to 7.6 g in different environments. Multi-environment QTL analysis of the four populations identified a total of 65 QTL ranging from 10 to 25 in each population. Meta-analysis of these component QTL of the four populations identified six 'consensus' QTL (C-QTL) in A3, A7, A10 and B3 by merging 33 of the 65 component Tsw QTL from different bi-parental populations. Allelic diversity analysis of these six C-QTL showed that Indian lines, Pusajaikisan and Varuna, hold the most positive allele in all the six C-QTL. In silico mapping of candidate genes with the consensus QTL localized 11 genes known to influence seed weight in Arabidopsis thaliana and also showed conserved crucifer blocks harboring seed weight QTL between the A subgenomes of B. juncea and B. rapa. These findings pave the way for a better understanding of the genetics of seed weight in the oilseed crop B. juncea and reveal the scope available for improvement of seed weight through marker-assisted breeding.