【作者】 陈彩艳；

【导师】 刘选明； 易自力；

【作者基本信息】 湖南农业大学 ， 植物学， 2001， 硕士

【摘要】 水稻株1S是新近选育并推广的籼型两系不育系，其育性转换临界温度低，配合力强，但株型偏高，尤其是所配组合植株偏高，影响了产量的进一步提高。本文对建立株1S体细胞无性系作了较为系统的研究，并筛选获得了矮杆突变体，同时对其矮化机理作了初步研究，取得了如下结果：1 建立了株1S体细胞无性系 以幼穗和成熟胚为外植体，在MS基本培养基中附加不同浓度的激素进行愈伤组织的诱导、继代、分化及再生苗的生根。结果发现，幼穗是一种比成熟胚更理想的外植体，MS+2，4-D2mg/L为最佳诱导培养基；2，4-D浓度过高或过低都不利于愈伤组织的诱导和增殖，6-BA对愈伤组织的增殖有抑制作用，但能促进愈伤组织的分化；愈伤组织的继代增殖和分化分别以MS+2，4-D2mg/L+6-BA0.2mg/L和MS+6-BA2mg/L为宜；MS+NAA0.5mg/L+IAA0.5mg/L和MS+NAA0.25mg/L+IAA0.25mg/L都可用于再生苗的生根，但前者根生长速度更快。愈伤组织以继代60d后的分化率最高。2 筛选出了矮杆突变体 将试管苗移栽于大田，经R2和R3代的考种和筛选，筛选出了SV5、SV10和SV14等三个矮杆突变株系。株高矮化明显，比原株1S矮化了25cm左右。突变株系及其与恢复系杂交的F1代植株同相应对照比较，除株高矮化外，其它性状与对照基本一致，育性与对照完全同步，起点温度比对照略低，千粒重变化不显著，虽穗总粒数、穗实粒数、结实率等略有降低，但单株有效穗数增加，单株产量略有提高，故突变株系株高、育性及经济性状都优于对照。通过对R2和R3代遗传特性进行田间观察和分析，突变株系到R2代性状就已经稳定，没有发生遗传漂变的现象，选育时间大为缩短。3 矮化机理分析 用SDS聚丙烯酰胺凝胶电泳对变异株系进行总蛋白分析后表明，变异株系在蛋白质水平上与对照差异明显，各变异株系之间也有明显差异，但所有变异株系与对照比较，均有两条共同的差异带，缺失Rf0.533一条带，多了一条带，RF值为0.544。 变异株系与对照比较，内源激素IAA和GA₃的含量都较低。株系间变异趋势不一致，SV5的GA₃含量比SV10和SV14低，但IAA含量要高更多还原

【Abstract】 Zhu- iS is a indica malesterile line which was bred lately and widely cultivated because of its low critical temperature of fertility and high ability of resistance, as well as wide cross-compatibility. But it is higher than expected. In order to get a dwarfing variant, somaclonal system was established and 3 expected dwarfing variant lines were obtained from somaclonal variation. In addition, some research on its underlying reason for dwarfing was conducted. The main results were as follows:1 Establishment of somacolonal system Callus was induced, subcultured and regenerated in the MS basic media with different hormones in different concentration. The result showed that young inflorescence was the better explant compared to mature seed. MS+2,4-D2mg/L was the best induce media. Just the same as high concentration of 2,4-D , less 2,4-D would inhibit the induction and proliferation of callus. Though it inhibited the callus induction and proliferation, 6-BA could improve the ability of differentiation of callus. MS+2,4-D2mg/L+6-BAO.2mg/L was suitable for subculture while MS+6BA2mg/L for regeneration. Roots formed easily in both MS+NAAO.5mg(L+IAAO.5mg/L and M5+NAAO.25mg/L+IAAO.25mg/L in different rates. The frequency of regeneration was the highest when the callus was subcultured for 60 days.2.Obtainment of dwarfing variants. The plant in vitro were planted in field.Three somaclonal variant lines桽V5, SV1O and SV14 were selected out from the R2 and R3 generations. The plant height of the three variant lines of R2 was 43.5, 49.3, 46.3cm each. Except lowering in height, all other agronomic traits of variant lines and Fl generation of variant line and restorer lines were similar to the control. Critical temperature was just the same. Though full grains and total grains per panicle, fertility and 1000-grain weight decreased a little, the yield increased a little as a result of the increase of total panicles per hole. With the observation of the traitS inheritance of R2 and R3, no drift was found.3.analysis of the cause of dwarfing Many differential protein binds were discovered between SV5, SV2 and control from the result of SDS-PAGE experiment. two differential bind whose RI were 0.533 and 0.544 were found coexisting in both the variantsBy the means of HPLC, the inner hormone content was measured. The result showed that the dwarfing lines contained less IAA and GA3 in the stem, SV5 had more IAA than SV1O and SV14, while less GA3 on the contrary.更多还原