【作者】 陈静；

【导师】 张海洋；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2017， 硕士

【摘要】 芝麻(Sesamum indicumL.,2n=26)属于胡麻科胡麻属,是世界上重要的油料作物之一,有着悠久的种植历史。近年来,随着我国对外贸易额的增加和人民生活水平的不断提高,对芝麻的需求量逐年增大。因此,生产上急需产量突破性的芝麻新品种以应对我国日益加剧的供需矛盾。矮化育种是芝麻高产育种的一个重要的方向。矮化资源作为培育矮杆株型品种重要的种质资源,已经在大多农作物中发现和应用,并对它们的矮化机理进行了深入的研究。目前,在芝麻中也发现和创造了一批矮化突变体,开展了大量的矮化基因的挖掘及其功能研究。但有关芝麻矮化突变体矮化机理仍需进一步明确。本研究以芝麻豫芝11号及其EMS诱变获得的矮化突变体Dw607为试验材料,在对突变体Dw607进行表型鉴定的基础上,对突变体Dw607矮化性状进行遗传分析,并从组织学和生理生化特性等方面探究该突变体的矮化机理。对矮化突变体Dw607的研究有利于我们在分子水平上研究芝麻矮化的成因,为芝麻分子育种奠定基础。本试验的主要研究结果如下:1、在表型鉴定及遗传分析方面,与野生型豫芝11号相比,矮化突变体Dw607在苗期的胚根和胚轴长度方面,以及在成熟期株高、平均节间长和蒴果长度等农艺性状方面均存在显著差异。进一步分析发现:突变体Dw607株高变矮主要由于节间长度缩短导致。分别利用一组六世代群体和五组F2:3群体对矮化突变体Dw607的株高性状进行遗传分析,结果均表明Dw607矮化性状受两对主基因控制。2、在组织学方面,与野生型豫芝11号相比,在播种后3天,纵切面细胞的长度和宽度均无大小差异;播种后6天,矮化突变体Dw607和豫芝11号细胞的平均长出现极显著性差异,纵切面细胞的平均宽度无显著差异;在播种后11和16天纵切面细胞长度和宽度均比豫芝11号小,差异显著。播种后11天,矮化突变体Dw607和豫芝11号茎秆横切面细胞的半径、皮层和木质部厚度基本相同;在播种后16天,二者表皮层的厚度无明显差异,但与豫芝11号相比,矮化突变体Dw607木质部增加较多,茎秆木质部增加较快,矮化突变体Dw607苗期粗壮。3、在光合特性方面,整个生育期矮化突变体Dw607和豫芝11号倒三叶叶绿素含量均呈现先升高后降低的走势,倒三叶类胡萝卜素呈升高走势。在芝麻现蕾期和初花期,与野生型豫芝11号相比,矮化突变体Dw607叶绿素含量较低,而类胡萝卜素含量较高;在盛花期和终花期,叶绿素含量较高,而类胡萝卜素含量较低。不同生育时期矮化突变体Dw607光合作用能力强于豫芝11号,光合作用产物主要用于促进其茎秆增粗或生殖生长。4、在内源激素含量方面,不同生育时期叶片、茎尖和根尖中5种内源激素(赤霉素GA、生长素IAA、脱落酸ABA、油菜素内酯BR和玉米素核苷ZR)含量测定,结果表明:二者内源激素的含量存在较大差异,突变体Dw607的矮化性状是由于多种植物激素共同作用的结果。其中,茎尖中内源激素含量与株高生长存在一定的相关性。不同浓度GA3处理均可促进短节矮化型突变体Dw607株高的增长,其中50 mg·L-1和100 mg·L-1浓度GA处理促进显著,对突变体Dw607的促进率分别达到11.62%和4.65%。低浓度(12.5 mg·L-1、25 mg·L-1)的IAA处理能促进突变体Dw607株高的增长,促进率分别为:1.16%和8.89%,高浓度(50 mg·L-1)则抑制矮化突变体Dw607的增长,促进率为-3.09%。更多还原

【Abstract】 Sesamum indicum L.(2n=26)belongs to the genus Flax,which is one of the most important oil crops in the world and has a long history of planting.In recent years,with the increase in the volume of foreign trade and the continuous improvement of people’s living standards,the demand for sesame seeds has increased year by year.Therefore,the production of urgent need for breakthrough production of new varieties of sesame seeds to cope with China’s growing supply and demand contradictions.Dwarfing breeding is an important direction for high-yielding breeding of sesame.Dwarfing resources are an important germplasm resource for cultivating dwarf plant type varieties and have been found and applied in most crops,and their dwarfing mechanism has been studied deeply.At present,a number of dwarf mutants have been discovered and created in sesame,and carried out a large number of dwarfing genes mining work.However,the dwarfing mechanism of sesame dwarf mutants remains to be further clarified.Based on the phenotypic identification of the mutant Dw607,the dwarfing trait of the mutant Dw607 was analyzed by genetic analysis of the dwarfing mutant Dw607,which was obtained from Sesame Yizhi 11 and its EMS mutant.Histology and physiological and biochemical characteristics of the dwarf mechanism of the mutant.The study of dwarf mutant Dw607 is helpful to study the causes of sesame dwarf at the molecular level and lay the foundation for sesame molecular breeding.The main results of this study are as follows:1.In phenotypic identification and genetic analysis,compared with the wild type Yuzhi 11,the dwarf mutant Dw607 had significant difference in the radicle and hypocotyl length of the seedling stage,as well as the agronomic traits of the plant height,average internode length and capsule length.Further analysis showed that the mutant Dw607 strain was mainly caused by shortening of internode length.Genetic analysis of the plant height traits of the dwarf mutant Dw607 was carried out by using a set of six generations of combined analysis and five F2:3 populations.The results showed that Dw607 dwarfing was controlled by two pairs of major genes.2.In terms of histology,compared with the wild-type Yuzhi 11,the length and width of the longitudinal cells were different at 3 days after sowing.At 6 days after sowing,the average length of the dwarf mutant Dw607 and Yuzhi 11 was significantly There were no significant differences in the mean width of longitudinal cells,and the length and width of the longitudinal sections were significantly smaller than those of Yuzhi 11 at 11 and 16 days after sowing.11 days after sowing,the radius of the cross-section cells of the dwarf mutant Dw607 and Yuzhi 11 were basically the same,and the thickness of the cortex and xylem was basically the same.After 16 days of sowing,there was no significant difference in the thickness of the epidermis 11,compared with the dwarf mutant Dw607 xylem increased more,the stems of xylem increased rapidly,dwarf mutant Dw607 seedling stout.3.In terms of photosynthetic characteristics,the contents of chlorophyll in Dw607 and Phyllostachys praecox were all increased first and then decreased,and the carotenoids of the three leaves were increased.The content of chlorophyll was low and the carotenoid content was higher in the dwarf mutant Dw607 than that in the wild type phytophthora stage at the bud stage and the early flowering stage.The chlorophyll content was higher in the flowering stage and the final flowering stage Carotenoid content is low.The photosynthetic capacity of dwarf mutant Dw607 was stronger than that of Yuzhi 11 at different growth stages.The photosynthetic products were mainly used to promote the thickening or reproductive growth of stem.4.In terms of endogenous hormone levels,the contents of five endogenous hormones(GA,Aminectin IAA,abscisic acid ABA,Brassinolide BR and zeatin ZR)in leaves,shoot tips and root tips of different growth stages were determined.The results showed that the two The content of endogenous hormones is quite different.The dwarfing traits of mutant Dw607 are the result of the interaction of various plant hormones.Among them,there was a certain correlation between endogenous hormone content and plant height growth.The results showed that 50 mg·L-1 and 100 mg·L-1 concentration of GA3could promote the treatment of Dw607,and the promotion rate of mutant Dw607 was 11.62%%And 4.65%respectively.The low concentration(12.5 mg·L-1,25 mg·L-1)of IAA could promote the growth of mutant Dw607,with the increase rates of 1.16%and 8.89%,high concentration(50 mg·L-1)Inhibited the growth of dwarf mutant Dw607 with a promotion rate of-3.09%.更多还原