重组自交系稻米品质性状的相关性分析及QTL定位

Correlation analysis and QTL mapping of grain quality-related traits in rice recombinant inbred line

【目的】分析重组自交系稻米品质性状的相关性,并对其进行数量性状座位(QTL)定位,为水稻品质性状遗传改良提供理论依据。【方法】以珍汕97B、柳沙油占202及二者杂交构建的174个重组自交系群体为材料,对12个稻米品质性状进行相关性分析和QTL定位。【结果】3个稻米碾磨品质性状(出糙率、精米率和整精米率)间均呈极显著正相关(P<0.01,下同)。6个稻米外观品质性状中,除粒长与垩白率、垩白度和透明度间无显著相关性(P>0.05)外,其他性状间均呈极显著正或负相关。3个稻米蒸煮食味品质性状中,胶稠度与直链淀粉含量和碱消值呈极显著负相关。碾磨品质性状、外观品质性状和蒸煮食味品质性状间也存在不同程度相关性,如垩白粒率和垩白度与除粒长外的其他9个性状呈显著(P<0.05,下同)或极显著相关等。在第5和第6染色体上共检测出出糙率、精米率、粒宽、长宽比、垩白率、垩白度、直链淀粉含量、胶稠度和碱消值9个性状的11个QTL,其中9个QTL的表型变异贡献率大于10%,为主效QTL,且显著或极显著相关性状的QTL定位区域存在趋同现象。【结论】重组自交系群体12个稻米品质性状存在互作效应,与QTL定位结果相互印证。鉴定所得主效QTL可用于水稻稻米品质相关性状的遗传改良。

[Objective]In the present study,correlation analysis of rice recombinant inbred line was studied,and quantitative trait loci mapping was carried out to provide reference for rice quality traits genetic improvement.[Method]One hundred and seventy-four recombinant inbred line(RIL)populations derived from the cross between Zhenshan 97B and Liushayouzhan 202 were used to conduct correlation analysis and QTL mapping of rice quality traits.[Result]Theresults showed that three traits of milling,namely percentage of brown rice,milled rice rate and head rice rate had extremely sig-nificant correlation between each other(P<0.01,the same below).Among the six appearance traits,except that grain length had no significant correlation with chalky grain rate,chalkiness and transparency(P>0.05),the other traits had ex-tremely positive correlation or extremely negative correlation between one and another.In the three cooking and eating quality traits,gel consistency had extremely negative correlation with amylase content and gelatinization temperature.Milling quality traits,appearance quality traits,cooking and eating quality traits also had correlation at various degrees.For example,chalky grain rate and chalkiness was significantly(P<0.05,the same below)or extremely correlated with all the traits except grain length.For the nine traits(percentage of brown rice,milled rice rate,grain width,ratio of length to width,chalky grain rate,chalkiness,amylase content,gel consistency and gelatinization temperature),eleven QTLs were identified locating on chromosome 5 and chromosome 6.There were nine QTLs whose phenotypic variation contri-bution rates were over 10%,they were major effects QTLs.The QTLs location area of the traits which had significant or extremely significant correlation between each other were apt to be located in the same region.[Conclusion]There are in-teraction effects among the 12 grain quality-related traits tested on recombinant inbred line populations.Such effects can be testified in the further QTL mapping detecting.Major QTLs detected in the present study can be used in genetic im-provement of rice quality-related traits.