【作者】 贾小丽；

【导师】 林文雄； 何海斌；

【作者基本信息】 福建农林大学 ， 生物化学与分子生物学， 2006， 硕士

【摘要】 长期以来，作物生产受到杂草的严重危害，人们通常运用化学除草剂来解决这一问题，但给环境和人类健康带来了负面影响。化感作用的应用将降低人们对化学除草剂的依赖程度，达到安全生态的目的。据此，研究水稻化感作用十分必要，并已取得较大的进展，但有关化感作用基因定位方面的研究还比较薄弱。本研究以水稻Lemont(弱化感)和Dular(强化感)杂交产生的重组自交系(recombinent inbred lines，RILs)及其亲本为供体植物，并以稻田主要杂草稗草为受体植物，采用迟播共培法测定供体植物对受体植物根长及其地上部植株的抑制率及其群体的频率分布，在此基础上，运用SSR分子标记技术，对控制水稻化感作用的基因进行了定位。结果如下： 通过琼脂迟播共培法考察了水稻RIL各家系及亲本的化感作用，结果表明，各家系对稗草的根长和茎长抑制率呈连续变异，证明了化感作用是数量遗传性状。对稗草根长的抑制率基本呈正态分布，而茎长抑制率分布正态性不典型，所以本文在QTL定位分析中采用了根长抑制率作为QTL定位的性状指标。群体对受体稗草的根长抑制率方差分析结果表明：供体家系间差异显著，即可进行遗传分析；该家系内差异不显著，说明不用剔除家系内效应即可进行以下的遗传分析，这时的误差方差源于家系内。 记录电泳检测到供体各家系在每个分子标记区段上的带型，构建水稻12对染色体的分子标记连锁图。共有12个连锁群，包含了98个分子标记，平均每对染色体覆盖长度283.26cM，相邻标记间的平均遗传距离为36.47cM，平均每对染色体上的标记位点数为8.17个。本研究所检测到的QTLs分别位于1、1、5、9、9号连锁群，解释了23.97％、15.21％、13.89％、18.63％、6.64％的遗传变异。根据受体根长抑制率的方差分析得出对表型变异的贡献率分别为11.83％、7.51％、6.86％、9.20％、3.28％。 最后，作者还就水稻化感作用的数量遗传与QTL定位研究存在的问题作了进一步讨论与建议。更多还原

【Abstract】 The crop production has been significantly affected by paddy weeds,it is always considered to control weed effectively by using herbicide.Hower, it takes great threaten to environment and human’s health in this measure.It therefore has been suggested that the application of allelopathy is an alternative weed control method.Progress has been made in rice allelopathy,but it must be paid attention to the researth on locating genes.In this study,the recombinent inbred line (RIL) drived from the crosses by the rice cultivar Lemont(weak allelopathy) with Dular(strong allelopathy) was applied to locate the genes associated with allelopathy against barnyardgrass.The results were summarized as follows:Allelopathic effect of the RIL population and their parents on the receiver plant, barnyardgrass, were detected by relay-seeding co-culture in agar(RCA) .And inhibitory effects of all entries on barnyardgrass root-length and shoot-height showed continuously variant,implying that allelopathy is a quantitative character.The frequency distribution of the inhibitory effect on the root-length of barnyardgrass was close to normal pattern,but that of inhibitory effect on the shoot-height of barnyardgrass showed slightly deviated normal pattern. Accordingly, the inhibitory effect on the root-length of barnyardgrass could be used as a quantitative trait for gene mapping.Variance analysis for the inhibitory effect on the root-length of barnyardgrass indicated that variance between the lines was significant and the reverse was true in the case between the blocks, suggesting that it could be subjected to genetic analysis under variance between the blocks.Banding patterns of every molecular marker fragment were detected by electrophoresis,and molecular marker linkage map in tweleve pairs of chromosomes in rice.The map was comprised of tweleve linkage groups and ninety-eight molecular markers covering per chromosome with 283.26cM span,36.47cM span per two molecular markers and 8.17 molecular markers per chromosome.Five QTLs associated with allelopathy against the target weed were respectively located in 1 1, 5, 9, 9 linkage group,and explained 23.97%, 15.21%, 13.89%, 18.63%, 6.64%更多还原