利用相关性分析鉴定与水稻根部性状表达相关的分子标记

84个水稻品种在营养液中生长,10天后测定每一品种的最大根长（Maximum Root Length,MRL)和根干重（Root Dry Weight,RDW)。选取其中有代表性的27个水稻品种,用扩增片段长度多态性（Amplified Fragment Length Polymor-phism,AFLP)技术进行基因组差异分析,通过计算差异带与性状表现间的相关系数,筛选与苗期水稻最大根长和根干重显著相关的分子标记,经过15对AFLP引物的筛选,有4对引物的7个片段的基因型表现与最大根长或（和）根干重显著相关,对其中的片段之一“T3P3f”进行克隆,测序后,设计特异PCR扩增引物“Z336”,进一步对84个水稻品种进行鉴定,统计分析后发现,Z2336与最大根长的相关系数为-0.193,相关性几近显著水平;与根干重的相关系数为-0.391,相关性达极显著水平,计算对根干重的差异解释率,可达15.3%,显示该标记与控制根干重性状表达的某个数量基因紧密连锁,它的存在对性状值的降低有显著的关系,进一步利用源于ZYQ8和JX17的加倍单倍体（double haploid,DH)分离群体进行基因定位,发现Z336位于水稻第11号染色体上,距离相邻的分子标记9.4cM。

Identification of Molecular Markers Associated With Rice Root Traits by Correlation Coefficient Analysis

After growing in nutrient solution for 10 days,84 rice varieties were harvested and measured in maximum root length (MRL) and root dry weight (RDW) separately. Twenty seven of them were selected as representative variety for correlated fragments screening with amplified fragment length polymorphism (AFLP) technique. After surveying with 15 pairs of AFLP primers,7 fragments from 4 pairs of primers were identified having significant correlation with MRL or/and RDW based on correlation coefficient analysis. One of them,"T3P3f", was cloned and sequenced, and its specific primers (Z336) were designed for the regular PCR amplification. Further analysis in 84 rice varieties revealed that correlation coefficient between Z336 and MRL was -0.193,much closer to the significant level of 5%;as between Z336 and RDW was -0.391,over the significant level of 1%. For the trait expression,Z336 could explain the root trait difference of 3.7% for MRL and 15.3% for RDW,respectively. The result shows the marker Z336 might tightly link with a QTL that has the negative relation with RDW expression. With a double haploid (DH) population from a cross of ZYQ8 and JX17,Z336 was finally anchored on rice chromosome 11 with a linked marker of 9.4 cM.