Genetic dissection and fine mapping of a novel dt gene associated with determinate growth habit in sesame

Abstract

BackgroundAs an important oil crop, growth habit of sesame (Sesamum indicum L.) is naturally indeterminate, which brings about asynchronous maturity of capsules and causes loss of yield.ResultsThe genetic basis of determinate growth habit in sesame was investigated by classical genetic analysis through multiple populations, results revealed that it was controlled by an unique recessive gene. The genotyping by sequencing (GBS) approach was employed for high-throughput SNP identification and genotyping in the F2 population, then a high density bin map was constructed, the map was 1086.403 cM in length, which consisted of 1184 bins (13,679 SNPs), with an average of 0.918 cM between adjacent bins. Based on bin mapping in conjunction with SSR markers analysis in targeted region, the novel sesame determinacy gene was mapped on LG09 in a genome region of 41 kb.ConclusionsThis study dissected genetic basis of determinate growth habit in sesame, constructed a new high-density bin map and mapped a novel determinacy gene. Results of this study demonstrate that we employed an optimized approach to get fine-accuracy, high-resolution and high-efficiency mapping result in sesame. The findings provided important foundation for sesame determinacy gene cloning and were expected to be applied in breeding for cultivars suited to mechanized production.

Construction of a High Density Genetic Map and QTL Mapping of PEG-Induced Drought Tolerance at Seedling Stage in Sesame Using Whole Genome Re-Sequencing

“…genetic map with 1354 bins on all 13 chromosomes. The average genetic length was 0.978 cM per bin, which was similar with previous maps [21,23]. Comparing with other sesame genetic maps developed by restriction-site associated DNA sequencing (RAD-seq) or GBS approach, WGS strategy could acquire much more variants.…”

“…Comparing with other sesame genetic maps developed by restriction-site associated DNA sequencing (RAD-seq) or GBS approach, WGS strategy could acquire much more variants. We obtained 466,911 high-quality SNPs and 72,981 InDels for bin markers assignment, which was more than 30 times of 13,679 SNPs identi ed by GBS in Zhang et al [23] and 11,924 SNPs detected by RAD-seq in Zhang et al [21]. The highdensity variants could improve the resolution of QTL and also help perform ne mapping of QTL controlling various agronomic traits.…”

“…In recent decades, with the development of next-generation sequencing (NGS) technology and the release of whole genome sequence of sesame, numerous SNP markers have been used for QTL genetic mapping and GWAS analysis. Bin-maps constructed by high-density SNP markers using NGS have been widely used in sesame QTL mapping [21,23].…”

Construction of a high density genetic map and QTL mapping of PEG-induced drought tolerance at the early seedling stage in sesame using whole genome re-sequencing

“…In the present study, we re-sequenced each RIL with an average read depth of 4.18× and construct a high-density genetic map with 1354 bins on all 13 chromosomes. The average genetic length was 0.978 cM per bin, which was similar with previous maps [22,40]. Comparing with other sesame genetic maps developed by restriction-site associated DNA sequencing (RAD-seq) or GBS approach, WGRS strategy could acquire much more variants.…”

“…Seedling weight, shoot length and root length were evaluated under both control and stress conditions. [22,40]. In the present study, we re-sequenced each RIL with an average read depth of 4.18× and construct a high-density genetic map with 1354 bins on all 13 chromosomes.…”