水稻和陆稻分化相关性状的QTL分析及水旱不同栽培条件下连续选择的影响

QTL Mapping of Characters Related to Lowland and Upland Rice Differentiationand Continuous Selection Effect under Different Lowland-upland Cultivation Conditions

本研究以来自云南的地方品种Ch5-10和Ch6-11为亲本,后代用SSD方法而得到的RIL9群体为试验材料,对水、陆稻差异性状(始穗期、剑叶宽、株高等)进行了考察,并利用SSR分子标记构建遗传连锁图谱,进行了各性状的QTL定位;在自然和人工选择的过程中,栽培稻无论是形态上还是基因组上,都发生多种多样的变化。利用F 2群体(父、母本和前述的SSD群体相同)采用Bulk混合选择的方法,在F 4代开始进行水、旱田两种条件下种植,以模拟水陆稻的分化条件,经过5代的种植后繁殖成株系,分别得到CA、CB两个群体。对这两个群体的水陆稻差异性状(始穗期、最高分蘖数、有效分蘖数、剑叶宽、株高等)进行了考察。结果表明,利用SSD方法而得到的RIL9群体对始穗期、剑叶宽、株高等3个性状进行QTL分析,两年共检测到19个QTL,分别位于1,2,3,7,8,9,11号染色体上。其中株高qPH-1效应最大,贡献率为22%(2009年安徽),16%(2009年北京),16%(2010年北京),表现为来自亲本Ch5-10的等位基因增加株高;利用Bulk方法而得到的CA群体(经过水田筛选5代、289个株系)和CB群体(经过旱田筛选5代、332个株系),考察其最高分蘖数、有效分蘖数、始穗期、株高、剑叶宽等5个性状。2009年安徽和北京两地试验发现:两群体间除安徽始穗期和北京剑叶宽差异不显著外,其他性状差异均达到极显著水平。根据氯酸钾抗性和低温发芽力的QTL定位结果,选择qSLtr-2、qSLratio-2、qRL28-2-1和qRL28-4附近的标记RM166、RM5472、RI05751和RM5979,及未定位到QTL的标记RM259对CA群体和CB群体进行基因型分析,两群体间t测验结果表明,RM5472、RI05751和RM5979差异均达到极显著水平,RM259和RM166差异不显著。说明在人工模拟水、陆稻选择的条件下这2个群体有了明显的分化。

Using local varieties Ch5-10 and Ch6-11 from Yunnan as parents,and the offspring of RIL9 population obtained by SSD method as experimental materials,the differences of water and land rice traits(beginning ear time,sword leaf width,plant height)were investigated.SSR molecular markers were used to construct genetic linkage maps,and QTL mapping was performed for each trait.In the process of natural and artificial selection,cultivated rice had undergone various changes both in morphology and genome.F 2 population(parent and parent were the same as the aforementioned SSD population)was planted in the F 4 generation under two conditions of water and dry field to simulate the differentiation conditions of water and land rice.After 5 generations of planting,the lines were propagated into CA and CB populations,respectively.The different characters of the two populations,such as first ear stage,maximum tillering number,effective tillering number,blade width and plant height,were investigated.Results showed that using the method of SSD RIL9 group's ear of beginning period,sword leaf width,plant height 3 traits QTL analysis,two years,a total of 19 QTL was detected,located on chromosome 1,2,3,7,8,9,11 respectively.The effect of qPH-1 on plant height was the largest,with the contribution rate of 22%(Anhui in 2009),16%(Beijing in 2009)and 16%(Beijing in 2010),which showed that alleles from Ch5-10 from parents increased plant height.The CA population(289 lines after 5 generations of paddy field screening)and CB population(332 lines after 5 generations of dry field screening)obtained by Bulk method were investigated,including the highest tillering number,effective tillering number,first heading period,plant height and blade width.The results of Anhui and Beijing experiments in 2009 showed that there was no significant difference in leaf width between Anhui and Beijing,and the difference in other traits reached a very significant level.According to QTL mapping results of potassium chlorate resistance and low temperature germination ability,RM166,RM5472,RI05751 and RM5979 markers near qSLtr-2,qSLratio-2,qRL28-2-1 and qRL28-4 were selected,and RM259 pairs of markers without QTL were not located.The genotype analysis of CA population and CB population showed that RM5472,RI05751 and RM5979 were significantly different,while RM259 and RM166 were not significantly different.The results indicated that the two populations had distinct differentiation under the simulated water and land rice selection conditions.