A high-density genetic map constructed using specific length amplified fragment (SLAF) sequencing and QTL mapping of seed-related traits in sesame (Sesamum indicum L.)

Hua Du,Haiyang Zhang,Yinghui Duan,Huili Wang,Libin Wei,Chun Li

doi:10.1186/s12870-019-2172-5

Abstract

BackgroundSesame (Sesamum indicum L., 2n = 2x = 26) is an important oilseed crop with high oil content but small seed size. To reveal the genetic loci of the quantitative seed-related traits, we constructed a high-density single nucleotide polymorphism (SNP) linkage map of an F2 population by using specific length amplified fragment (SLAF) technique and determined the quantitative trait loci (QTLs) of seed-related traits for sesame based on the phenotypes of F3 progeny.ResultsThe genetic map comprised 2159 SNP markers distributed on 13 linkage groups (LGs) and was 2128.51 cM in length, with an average distance of 0.99 cM between adjacent markers. QTL mapping revealed 19 major-effect QTLs with the phenotypic effect (R2) more than 10%, i.e., eight QTLs for seed coat color, nine QTLs for seed size, and two QTLs for 1000-seed weight (TSW), using composite interval mapping method. Particularly, LG04 and LG11 contained collocated QTL regions for the seed coat color and seed size traits, respectively, based on their close or identical locations. In total, 155 candidate genes for seed coat color, 22 for seed size traits, and 54 for TSW were screened and analyzed.ConclusionsThis report presents the first QTL mapping of seed-related traits in sesame using an F2 population. The results reveal the location of specific markers associated with seed-related traits in sesame and provide the basis for further seed quality traits research.

Highlights

Sesame (Sesamum indicum L., 2n = 2x = 26) is an important oilseed crop with high oil content but small seed size
Phenotypic analysis of seed-related traits in F3 progeny under two environments In sesame, the appearance quality of seed is involved in seed size, seed weight, and seed coat color
The phenotypic variation of 17 indicators related to seed size, the value of 1000-seed weight (TSW), and seed coat color traits in the F3 generation and two parents grown in two different environments was investigated (Figs. 1 and 2; Table 1)

Summary

Introduction

Sesame (Sesamum indicum L., 2n = 2x = 26) is an important oilseed crop with high oil content but small seed size. Sesame (Sesamum indicum L.), a diploid species (2n = 2x = 26), is one of the most ancient and important domestic oilseed crops, with small genome size of 354 Mb [1, 2]. To the best of our knowledge, there are no reports on the location of QTL and genes related to seed size traits in sesame, and genes controlling seed coat color and seed weight are yet to be identified in this species. Discovery of QTL and genes related to seed size, seed coat color, and seed weight is requisite for developing sesame molecular breeding techniques

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Discussion

Conclusion