【作者】 王洋；

【导师】 洪德林；

【作者基本信息】 南京农业大学 ， 种子科学与技术， 2009， 博士

【摘要】 水稻直播是一种轻型、高效、节水的栽培方式,为欧美等国和许多发达地区广泛采用。随着我国经济的快速发展,大量劳动力从农村转向城市,水稻直播栽培面积开始呈逐年上升的趋势。直播种子成苗好坏是直播栽培成功与否的第一关。影响直播种子成苗的主要因素是缺氧胁迫和低温胁迫。培育具有耐缺氧能力和高活力的直播水稻品种是将会提高直播稻田间成苗率的途径之一。太湖流域是水稻主栽区,品种资源具有广泛的遗传多样性。为发掘种子活力和幼苗耐缺氧能力优异等位变异及其载体材料,本论文进行了以下3项研究。一是选取297个太湖流域水稻品种资源对种子活力和幼苗耐缺氧能力进行遗传变异研究,并对种子活力和幼苗耐缺氧能力与直播成苗能力进行相关分析。二是利用一个籼粳交BIL群体和一个粳粳交RIL群体对种子活力和幼苗耐缺氧能力进行QTL分析。BIL群体由Nipponbare/Kasalath//Nipponbare组合98个家系构成；RIL群体由秀水79/C堡组合247个家系构成。三是利用由94个太湖流域水稻核心种质构成的自然群体对种子活力和幼苗耐缺氧能力进行关联作图分析。获得的主要结果如下：1.5个生态类型297个水稻地方品种间种子活力和幼苗耐缺氧能力的遗传变异系数分别为19.5%和15.2%。这两个性状的遗传变异主要存在于早熟晚粳生态型中。种子活力指数、缺氧条件下芽鞘长度均与水直播14天的幼苗高及成苗指数呈极显著正相关。从早熟晚粳中筛选到薄稻3、硬头茎、三百粒头、大稻头、乌金香糯、荒三石4和晚八哥头这7个高活力和耐缺氧能力的品种资源,可供适于直播的水稻新品种选育利用。2.对于种子活力性状,在籼粳交BIL群体的双亲中,Kasalath有利等位变异数目(6个)多于Nipponbare(1个)；在粳粳交RIL群体的双亲中,C堡有利等位变异数目(8个)多于秀水79(1个)；在太湖流域水稻自然群体中共检测到42个控制种子活力性状的优异等位变异。BIL群体中,亲本Kasalath有2个控制根长的有利等位变异,分别位于第1和第7染色体上,与之紧密连锁的RFLP标记是C813和R3089；有2个控制苗高的有利等位变异,分别位于第7和第8染色体上,与之紧密连锁的RFLP标记为C847和C166；有2个控制幼苗干重的有利等位变异,位于第7和第8染色体上,与之紧密连锁的RFLP标记是R3089和C166。Nipponbare只有1个控制干重的有利等位变异位,位于第1染色体上,与之紧密连锁的RFLP标记是C122。RIL群体中,亲本C堡有2个控制根长的有利等位变异,位于第1和第2染色体上,有利等位变异为RM486-112bp和RM48-240bp;4个控制苗高的有利等位变异,位于第2、3、8和11染色体上,有利等位变异为RM48-240bp、RM545-220bp. RM6948-116bp和RM206-165bp;2个控制幼苗干重的有利等位变异,位于第2和第6染色体上,有利等位变异是RM2127-175bp和RM454-170bp。秀水79只有1个控制干重的有利等位变异位,位于第1染色体上,有利等位变异是RM525-143bp。太湖流域水稻自然群体中,检测到42个控制种子活力性状的优异等位变异,其中控制根长的优异等位变异17个,控制苗高的优异等位变异13个,控制幼苗干重的优异等位变异12个。第1染色体上控制根长的优异等位变异RM486-112bp,第8染色体上控制苗高的优异等位变异RM6948-116bp,在RIL群体中也被检测到。3.对于幼苗耐缺氧能力,在籼粳交BIL群体的双亲中各有3个有利等位变异；在粳粳交RIL群体的双亲中,2个有利等位变异均来源于C堡。在太湖流域粳稻自然群体中共检测到6个优异等位变异。BIL群体中,亲本Nipponbare有3个控制幼苗耐缺氧能力的有利等位变异,分别位于第2、第3和第9染色体上,与之紧密连锁的RFLP标记为C747、C1488和R2272；亲本Kasalath有3个控制幼苗耐缺氧能力的有利等位变异,分别位于第5、第8和第12染色体上,与之紧密连锁的RFLP标记为R830、C1121和R642。RIL群体中,2个控制幼苗耐缺氧能力的有利等位变异均来自亲本C堡,分别位于第2和第7染色体上,有利等位变异为RM525-140 bp和RM418-250 bp。大湖流域水稻自然群体中检测到的6个控制幼苗耐缺氧能力的优异等位变异分别是RM112-127bp、RM317-164bp、RM317-157bp、RM311-176bp、RM311-170bp和RM20-205bp。4.获得了42个携带种子活力优异等位变异的载体材料和6个携带幼苗耐缺氧能力优异等位变异的载体材料。在关联群体中发掘出的42个携带种子活力优异等位变异的载体材料中,携带根长效应值较大的优异等位变异载体材料为滇屯502选早、扬稻6号和南农粳62401；携带苗高效应值较大的为开青和籼恢429；携带幼苗干重效应值较大的为滇屯502选早和C堡。有的载体材料同时携带2个性状优异等位变异,如扬稻6号同时携带根长和苗高有利等位变异,孔雀青同时携带根长和干重有利等位变异,籼恢429同时携带苗高和幼苗干重有利等位变异。另一方面,一些载体材料同时携带同一活力性状的2个以上的有利等位变异,如阳光200携带根长的两个有利等位变异,恶不死糯稻、苏粳4号和水晶白稻携带干重的两个有利等位变异。也有一些品种既携带有2个性状优异等位变异,同时又携带其中的一个性状2个以上优异等位变异,如滇屯502选早携带2个根长和1个幼苗干重优异等位变异,开青携带2个苗长和1个根长优异等位变异。在关联群体中发掘出的6个携带幼苗耐缺氧能力优异等位变异的载体材料,分别为开青、白芒糯、镇稻88、有芒早稻、粗杆黄稻和C堡,其中以镇稻88中优异等位变异的效应值最大。开青、镇稻88和C堡等品种既携带水稻种子活力又携带幼苗耐缺氧能力优异等位变异,可考虑优先用作培育适于水稻直播品种的亲本资源。更多还原

【Abstract】 Direct seeding in rice (Oryza sativa L.) is a cultivation pattern of light-labor, high effect and water-saving. It is widely adopted in America, Europe and other developed countries. With the rapid development of national economy in our country, and more and more labor force moving from countryside to city, the areas of direct sowing in rice is increasing year after year. Whether the cultivation of direct seeding in rice is successful is first determined by the situation of seedling establishment in the field. Anoxic stress and lower temperature stress are the main factors affecting seedling establishment in direct seeding rice field. Breeding rice cultivars with anoxic tolerance and high vigor is one of the ways to improve seedling establishment in direct sowing field. Rice has been widely cultivated in the Taihu lake region, Jiangsu Province, and maintained broad genetic diversity during the long history of rice cultivation. In order to discovery favorable alleles for seed vigor and seedling tolerance to anoxia, we conducted following studies. Firstly, genetic variation of seed vigor and seedling tolerance to anoxia, and the correlations between the traits mentioned above with seedling establishment index were studied by using 297 accessions of rice in Tai lake region. Secondly, QTL mapping was carried out for the traits of seed vigor and seedling tolerance to anoxia by using a BIL population (98 lines) made from a backcross of Nipponbare (japonica)/Kasalath (indica)//Nipponbare and a RIL population (247 lines) made from a cross between Xiushui 79 (japonica cultivar) and C Bao(japonica restorer). Thirdly, association mapping was conducted for the traits of seed vigor and seedling tolerance to anoxia by using a natural population composed of 94 accessions from Taihu lake region. The main results were obtained as follows:1. Genetic coefficient of variation was 19.5% for seed vigor and 15.2% for tolerance to anoxia among the 297 accessions(belong to five ecotypes). The genetic variations of the two traits were mainly existed in early maturity late japonica rice ecotype. Highly significant positive correlations were found between the two traits respectively with 14-day-seedling height and seedling establishment index. Seven accessions with high seed vigor and high tolerance to anoxia were screened out from early maturity late japonica rice ecotype. They were Bodao3, Yingtoujing, Sanbailitou, Dadaotou, Wujinxiangnuo, Huangsanshi4, Wanbagetou. They could be utilized as parents in breeding programs which aim to develop varieties suitable for direct seeding technology.2. For trait of seed vigor, six favorable alleles in Kasalath and one favorable allele in Nipponbare were detected in BIL population, and eight favorable alleles in C-Bao and one favorable allele in Xiushui79 were detected in RIL population. Forty-two favorable alleles for seed vigor trait were explored in the natural population.In BIL population, Kasalath carried two favorable alleles for root length which located on 1 and 7 chromosomes tightly linked to RFLP marker C813 and R3089, two favorable alleles for shoot height which located on 7 and 8 chromosomes tightly linked to RFLP marker C847 and C166, and two favorable alleles for seedling dry weight which located on 7 and 8 chromosomes tightly linked to RFLP marker R3089 and C166. Nipponbare only carried one favorable allele for seedling dry weight which located on 1 chromosomes tightly linked to RFLP marker C122.In RIL population, C-Bao carried two favorable alleles, RM486-112bp and RM48-240bp, controlling root length which located on 1 and 7 chromosomes. Four favorable alleles, RM48-240bp, RM545-220bp, RM6948-116bp and RM206-165bp, controlling shoot height which located on 2,3,8 and 11 chromosomes, and two favorable alleles, RM2127-175bp and RM454-170bp, controlling seedling dry weight which located on 2 and 6 chromosomes. Xiushui79 only carried one favorable allele RM525-143bp controlling seedling dry weight which located on 2 chromosomes.In the natural population, totally 42 favorable alleles were detected for the traits of seed vigor. Among them, seventeen favorable alleles were for root length, thirteen were for shoot height, and twelve were for seedling dry weight. The favorable allele, RM486-112bp, detected on chromosome 1, for root length, and the favorable allele RM6948-116bp, detected on chromosome 8, for shoot height, were also detected in the RIL population.3. For seedling anoxic tolerance, Kasalath and Nipponbare both carried three favorable alleles in BIL population. All favorable alleles for the trait came from C-Bao in RIL population. Six favorable alleles for seedling anoxic tolerance were explored in the natural population.In BIL population, Nipponbare carried three favorable alleles controlling seedling anoxic tolerance which located on chromosomes 2,3 and 9, tightly linked to RFLP marker C747, C1488 and R2272. Kasalath carried three favorable alleles controlling seedling anoxic tolerance which located on chromosomes 5,8 and 12, tightly linked to RFLP marker R830, C1121 and R642.In RIL population, two favorable alleles, RM525-140bp and RM418-250bp, were detected on chromosome 2 and chromosome 7 in C-Bao for seedling anoxic tolerance.Six favorable alleles for seedling anoxia tolerance detected in natural population were RM112-127bp, RM317-164bp, RM317-157bp, RM311-176bp, RM311-170bp and RM20-205bp.4. Torty-two accessions carring favorable alleles for seed vigor and 6 accessions carring favorable alleles for seedling anoxic tolerance were discovered.Among the 42 accessions discovered in the natural population, Diantun 502 xuan zao, Yangdao 6 hao and Nannongjing62401 carried positive allele with larger effect for root length. Kaiqing and Huixian429 carried positive allele with larger effect for shoot height. Diantun 502 xuan zao and C-Bao carried positive allele with larger effect for seedling dry weight. Some materials carried favorable alleles for two seed vigor traits such as Yangdao6hao (root length and shoot height), Kongqueqing(root length and dry weight), Huixian429(shoot height and dry weight). On the other hand, some materials carried more than two favorable alleles for one seed vigor traits such as Yangguang2000 (root length), Ebushinuodao(dry weight), shujing4hao(dry weight) and shuijingbaidao(dry weight). Some materials carried two favorable alleles for two seed vigor traits as well as two favorable alleles for one seed vigor traits such as Diantun 502 xuan zao(two for root length and one for dry weight) and Kaiqing(two for shoot height and root length).Six varieties possessing favorable alleles for anoxic tolerance discovered in natural population were Kaiqing, Baimangdao, Zhendao88, Youmangzaodao, cuganhuangdao and C-Bao. Zhendao88 carried positive allele with the largest effect for anoxic tolerance.Kaiqing, Zhendao88 and C-Bao which carried favorable alleles not only for seed vigor but also for anoxic tolerance could be utilized as parents in breeding programs which aim to develop varieties suitable for direct seeding technology.更多还原