水稻粒型和粒重的QTL定位分析

利用以两个籼稻品种H359和Acc8558为亲本杂交建立的重组自交系群体及相应的分子标记连锁图，对水稻粒长、粒宽和粒重进行了QTL定位分析。检测到15个与粒长有关的QTL、17个与粒宽有关的QTL及16个与粒重有关的QTL，它们可分别解释75．91％、76．20％和81．40％的表型变异。其中在5号染色体上检测到1个控制粒宽的主效QTL，可解释26．65％的表型变异。粒长和粒宽之间虽然相关显著，但相关系数很小(r=0．180)。而QTL分析结果也显示，两者的QTL位置很少相同。这说明粒长和粒宽有不同的遗传基础。粒长和粒宽与粒重的相关系数分别为0．781和0．461，直接通径系数分别为0．7220和0．3299。QTL定位结果也显示，粒长与粒重的QTL位置相近或重叠的较多。因此，粒长对粒重的贡献较大。

Mapping of QTLs Underlying Grain Shape and Grain Weight in Rice

Using a recombinant inbred line (RIL) population derived from a cross between two indica rice varieties, H359 and Acc8558, and a corresponding molecular marker linkage map, QTLs controlling grain length (GL), grain breadth (GB) and grain weight (GW) were analyzed. Fifteen QTLs for GL, 17 for GB and 16 for GW were detected, which could explain 71.91%, 76.20% and 81.4% of the phenotypic variation, respectively. A major QTL for GB was detected on chromosome 5, which could explain 26.65% of the phenotypic variation. Although the correlation between GL and GB was statistically significant, the correlation coefficient was very small (r = 0.180).QTL mapping also showed that GL and GB seldom shared common QTLs. These results suggest that GL and GB have different genetic bases. The correlation coefficients of GL and GB with GW were 0.781 and 0.461, respectively; and their coefficients of direct path to GW were 0.722 and 0.330, respectively. QTL mapping also showed that GW shared more common QTLs with GL than with GB. These results suggest that GL contributes more to GW.