【作者】 蒋方山；

【导师】 李斯深；

【作者基本信息】 山东农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 小麦基部和顶部小穗常常不育是影响穗粒数的重要因素。推广的小麦品种中,顶部小穗不育的问题在很大程度上得到了解决。但大多数品种总有1～2个基部小穗不育,极少见到基部小穗完全可育的品种。因此,增加基部小穗的育性,进而增加穗粒数,是提高小麦产量的关键问题之一。我们利用EMS诱变基部小穗完全可育的小麦品系山农1186,获得了稳定遗传的基部小穗不育的突变体,命名为BSS（basal spikelet sterility）突变体。本研究对该突变体进行了农艺性状鉴定、小穗发育过程观察、遗传变异分析、相关基因片段克隆。主要结果如下:（1）10个突变体的基部有2～4个不育小穗,而山农1186基部小穗正常结实;与受体山农1186相比,10个突变株系的穗长、小穗数无显著变化,但穗粒数显著降低;突变株系的株高,穗下、倒二、倒四、倒五节间长度显著增加,表明株高的增加是由多个节间伸长造成的;大多数株系的旗叶、倒二叶、倒三叶宽度显著变窄。BSS突变体的农艺性状间存在相关关系。株高、穗下节间长和倒二节间长度与不育小穗数呈显著正相关;旗叶宽、倒二叶宽、倒三叶宽及穗粒数与不育小穗数呈极显著负相关。（2）对小穗发育的形态学观察发现,BSS突变体基部小穗在四分体时期开始退化,雌蕊、雄蕊、子房萎焉失水,变成模糊的一团组织,进而导致基部小穗不育。（3）从305对EST-SSR引物中筛选出28对在山农1186和BSS突变体之间具有稳定多态性的引物。28对EST-SSR引物在BSS突变体中检测到133个等位位点,每对多态性引物检测出2～6个等位位点,其中多态性等位位点为43个,占32.33%。（4）应用mRNA差异显示技术研究了受体山农1186和BSS突变体孕穗期幼穗的基因表达差异。获得了7个可能和基部小穗育性相关的cDNA片段:BSS₁～BSS₇。BSS₃与水稻、拟南芥等植物的琥珀酸脱氢酶具有很高的同源性（99%）,推测BSS₃参与植物三羧酸循环,调节物质和能量的代谢,可能属于广谱性的调节基因;BSS₄与小麦含有保守F-box区域的EST序列ta94166的451～820区段同源性达到95%,与水稻F-Box蛋白质EAZ17658.1、EAY80184.1具有很高的同源性。推测BSS₄可能是F-Box基因,在小麦幼穗发育过程中调节B类基因的功能。更多还原

【Abstract】 Basal and apical spikelets sterility was important factors influencing grain number per ear. Apical spikelets sterility had been solved to a large extent for wheat cultivars. While most wheat varieties still have 1～2 sterile distal spikelets, and it’s rare that all basal spikelets are fertile. So improving basal spikelets fertility, and finally increasing grain number per ear has become one of the key problems to increase wheat yield. We gained basal spikelets sterility mutant （BSS） via EMS inducing Shannong1186 which basal spikelets were completely fertile. In this study, we studied on it’s agronomic traits, development of the spikelets and the genetic variation. DDRT-PCR （mRNA differential display PCR） technology was applied in order to clone the genes related to basal spikelets. The results were as follows:（1） The investigation on agronomic traits showed that 2-4 distal spikelets of all the 10 mutant lines were sterility. However, the distal spikelets of Shannong1186 were fertile. Compared with Shannong1186, grains per spike of all the 10 mutant lines decreased significantly; plant height, length of the first, second, fourth and fifth node from top of all the mutant lines increased significantly. It indicated that the increased length of multi nodes led to the increase of plant height; the width of flag leaf, penultimate leaf and the third leaf from top for the most mutant lines decreased significantly. There were some correlation among agronomic characters. There were significant positive correlation between plant height and distal sterility spikelets per spike, between length of the first node from top and distal sterility spikelets per spike, between length of the second node from top and distal sterility spikelets per spike. The correlation coefficients between flag leaf width and distal sterility spikelets per spike, between penultimate leaf width and distal sterility spikelets per spike, between Width of the third node from topdistal sterility spikelets per spike, between grains per spikedistal sterility spikelets per spike were significant negative at the 0.01 level.（3） Observation on spikelet morphological development showed that distal spikelets of the mutant began to degrade in tetrad stage. Pistils, stamens and ovaries of mutants became wilt and turn to illegibility organism. Degeneration was the reason why distal spikelets of mutants were sterility. Distal spikelets of Shannong1186 could develop normally in tetrad stage.（4） 305 EST-SSR were screened and 28 ones amplified different fragments between Shannong1186 and BSS mutant. The 28 polymorphic primer sets produced 133 amplified fragments, 2～6 fragments per primer pair, of which 43 （32.33%） were polymorphic.（5）mRNA differential display was used to analyze the differential expression of genes between Shannong1186 young panicles and BSS mutant young panicles. Seven differential fragments related to basal spikelets had been obtained: BSS₁～BSS₇. BSS₃ had highly homology （99%） with succinate dehydrogenase （SDH） in rice and Arabidopsis Thaliana. The results suggested that BSS₃ maybe accommodate metabolism of substance and energy by tricarboxylic acid cycle （TCA cycle）, and finally regulated basal spikelets development in wheat. BSS₃ may belong to a broad regulated gene. BSS₄ was of highly homology with F-Box gene （ta94166） and protien （EAZ17658.1, EAY80184.1）. F-Box was very important to function of B-type gene that controled petal and stamen development.更多还原