芝麻产量主要组成性状相关基因功能及调控研究

Sesame(Sesamum indicum L.,2n=26)is one of the most important oil crops for the high oil quality in the world. Compare with the sesame producing countries, sesame production of China ranks at the second position and the yield ranks at the first. However, sesame is still regarded as a low yield crop. Raising the yield and stabilizing the high yield potential is the key points in worldwide sesame breeding research in the past two decades.The yield trait in sesame is a quantitative trait, as capsule number per plant, 1000 seed weight and seed number per capsule are the three principal yield components and show the significant and positive correlation to the yield trait. Till now, no reports about functional analyses of genes related to the yield trait in sesame have yet been published. In the recent few years, obtaining of a great deal of sesame mutants associated with the yield trait and sesame genome sequencing and assembly, as well as the rapid construction of genome and transcriptome data analysis platform for sesame, supply the new path for clarifying genetic mechanisms of sesame yield formation. Therefore, 30 sesame mutants with mutated yield traits will be sequenced using genome resequencing in the programme. Candidate genes related to yield component traits will be cloned in a large scale, and regulation mechanisms of multiple key functional genes are eager to be explored. With the availability of sesame genome reference, the function pattern and the interplay between the main yield components would be revealed, which will supply the theoretical basis for sesame high yield molecular breeding.

芝麻（Sesamum indicum L., 2n=26）是世界上重要的特色油料作物。我国芝麻年产量居世界第二位，单产居世界第一。但是芝麻属低产作物。提高单产、增加稳产性一直是近20年来国内外芝麻育种研究工作的重点。产量属数量性状，单株蒴果数、千粒重和单蒴粒数是芝麻产量性状的3大主要组成（principal yield components）。尚未见有关芝麻产量性状相关基因功能研究的报道。近几年来，大批芝麻产量相关突变体的获得、芝麻基因组测序拼接的完成以及芝麻基因组、转录组数据分析平台的快速构建均为探索芝麻产量性状遗传机理提供了新途径。为此，项目拟利用30份芝麻产量组成性状突变材料，借助基因组信息和重测序技术，开展芝麻产量组成相关基因大规模克隆和功能研究，以探明重要功能基因调控机理，阐明芝麻主要产量组成相互作用规律和特征，为芝麻高产分子育种奠定理论基础。

芝麻是世界上重要的特色优质油料作物。我国芝麻年产量居世界第二位，单产居世界第一。相对于其他粮油作物，芝麻仍属于低产作物，提高单产、增加稳产性一直是近几十年来国内外芝麻育种研究工作的重点。为深入阐述芝麻产量性状相关基因功能，探明芝麻主要产量组成部分相互作用规律及特征，项目组开展了芝麻产量相关突变体创制与遗传分析、芝麻产量性状遗传解析以及芝麻产量性状相关基因定位与功能研究等工作。借助于芝麻EMS诱变及T-DNA转化技术，项目组获得了大批量突变体材料，具有可稳定遗传的突变体数千份，性状涉及蒴果大小、籽粒大小、株型、叶型等优异特性，为进一步开展芝麻产量等重要性状遗传研究提供了材料基础。项目系统开展了560份芝麻核心种质的8个产量相关性状指标调查及遗传解析，明确了单株蒴果数等4个产量主要组成成分及相关关系，阐述了环境及基因型对芝麻产量性状的影响。以豫芝11号基因组精细图为参考，选用369份核心种质及112个SSR标记开展了产量性状关联分析，共筛选出与株高等8个产量相关性状紧密连锁(P<0.001)的SSR标记71个，确定产量相关基因28个；选用创制的178份产量相关EMS突变体大规模开展了突变基因位点定位研究，获得了与籽粒大小、蒴果大小等相关的突变基因位点23个。借助于高效芝麻图位克隆+重测序技术等体系，完成了芝麻花序有限基因Sidt1、卷叶闭蒴基因Sicl1、短节间长度基因Sidw1、蒴果大小基因Sics1和Sics2的克隆，揭示了芝麻重要功能基因及产量调控规律。此外，项目组还开展了芝麻花序有限、短节密蒴等新品种选育与试验示范工作。先后选育出豫芝Dw607等5个适于机械化生产的芝麻新品种（系），并创造出了亩产223.6公斤的芝麻大面积种植世界最高单产纪录，进一步推动了我国和世界芝麻生产。