【作者】 武军；

【导师】 王辉； 李立会；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2006， 博士

【摘要】 小麦近缘植物存在着极为丰富的遗传多样性和可供改良小麦的优异基因,加强小麦与其近缘植物的杂交、鉴定和利用研究,必将为小麦生产和育种带来更大的进展。本研究通过细胞学、原位杂交、种子储藏蛋白电泳、分子标记及形态学统计,对小麦-冰草衍生后代中大穗多花和成穗受抑制两类材料进行了系统的鉴定与分析。主要结果如下:1.小麦-冰草特异种质的外源物质检测通过基因组原位杂交(GISH)分析,在大穗多花4844后代的15个株系中检测出一个稳定的附加系(4844-12)和两个稳定的代换系(4844-2、4844-8);GISH结果还表明,成穗受抑制株系发生了两对小麦染色体与冰草间的插入易位,插入到小麦染色体短臂近末端的两个冰草染色体片段分别占整条易位染色体总长的13%、10%,占短臂的29.6%、23%左右,并利用微卫星分析从成穗受抑制株系中筛选出6个SSR易位标记。2.大穗多花小麦-冰草附加系、代换系的遗传分析通过附加系、代换系及4844后代单株的每穗小穗数、小花数和穗粒数的统计分析与GISH分析,结果表明,4844后代株系的多花、多粒特性是由外源冰草染色体引起的,此冰草染色体在小麦背景下,能够大幅度增加小麦的穗粒数;利用来自山羊草的重复序列pAs1对代换系4844-2、4844-8进行荧光原位杂交FISH和SSR分析,小麦的6D染色体被1对冰草染色体代换,由于这两个代换系是自发发生的,其植株生长正常,说明这对冰草染色体对小麦6D染色体具有良好的补偿作用,由同源补偿代换推断此冰草染色体与小麦第六同源群有部分同源关系,并定名此冰草染色体为6P;EST-SSR与醇溶蛋白(Gliadin)分析进一步验证6P与小麦第六同源群的部分同源关系的划分是正确的;同时筛选出5个冰草6P染色体的SSR标记。3.大穗多花小麦-冰草基因渐渗系3228-2穗部性状的遗传分析对3228-2×京4839的F2群体穗粒数和穗小花数用IECM算法估算结果表明,穗粒数由一对主基因+多基因控制,主基因表现为加性和显性或超显性,其遗传模型是A-4,F2群体控制穗粒数的主基因遗传率h2mg为56.3%;而穗小花数由二对主基因+多基因控制,主基因表现为加性-显性-上位性模型,其遗传模型是B-1,F2群体控制穗小花数的主基因遗传率h2mg为96.7%。4.普通小麦-冰草衍生后代中抑制成穗基因SiFc的分子标记及染色体定位利用小麦SSR与EST-SSR分子标记技术和F2分离群体分组分析法研究表明,该抑制成穗的性状受一对隐性基因控制,位于小麦1A染色体短臂的近端部,与Ksum104、Ksum117、Xcfa2153和WMC24四对引物所扩增的成穗受抑制的标记具有连锁关系,且Ksum104引物所扩增的标记紧密连锁,它们之间的遗传距离为4.5 cM。5个位点在分子图谱上的顺序为1AS-Xcfa2153-Ksum117-Ksum104-SiFc-WMC24。更多还原

【Abstract】 Cytological, in situ hybridization, gliadin, molecular markers and morphological Stat. were employed to detect and analyze two kinds of peculiar wheat germplasm derived from wheat (Triticum aestivum L.) - Agropyron cristatum (2n=28, genomes PPPP). Major result is as follows:1. To detect exogenous hereditary property of the derive descendants from wheat- A. cristatum A large-spike with more floret wheat germplasm (4844) and earing inhibition plant lines were obtained by screening the descendants from hybridizing between common wheat (T. aestivum L.) and Agropyron cristatum (accession Z559). The results of genomic in situ hybridization (GISH) detect, a disomic alien chromosome addition line 4844-12 and two chromosome substitution lines 4844-2 and 4844-8, in 15 progeny lines of 4844. GISH result still shows, these earing inhibition plant lines belonged to the translation lines between two couple wheat chromosomes and A. cristatum chromosomes. Total six translational markers were detected by using SSR analysis in them.2. The hereditary analysis of the supper spike wheat- A. cristatum addition line and substitution lines In order to determine the genetic control of multiple florets and kernels per spike in this line, chromosome addition and substitution lines that were derived from line 4844 were characterized by means of in situ hybridization, microsatellite (SSR), and gliadin analyses. Genomic in situ hybridization analysis with biotinylated P genomic DNA of A. cristatum as a probe demonstrated that the increased number of florets and grains in a spike was associated with the A. cristatum chromosome introgressed. Fluorescence in situ hybridization, using a repetitive sequence, pAs1 derived from Aegilops squarrosa L., indicated the replacement of chromosome 6D of wheat in the wheat-A. cristatum chromosome substitution lines. This was confirmed by microsatellite analyses with wheat SSR markers specific for chromosome 6D, suggesting that the A. cristatum chromosome was homoeologous to group 6 and was therefore designated 6P. This verdict was further confirmed by amplification using EST-SSR markers and gliadin analysis. The increased number of florets and kernels within a spike of the wheat-A. cristatum hybrids was thus controlled by gene(s) located on A. cristatum chromosome 6P. At the更多还原