水稻芽期耐寒性综合评价及耐寒指标筛选

为筛选水稻芽期耐寒指标并建立可靠的水稻芽期耐寒性数学评价模型,采用49个水稻种质资源,测定发芽率(GR)、相对发芽率(RGR)、发芽势(GP)、相对发芽势(RGP)、发芽指数(GI)、种子萌发指数(PI)、平均发芽时间(MGT)、成苗率(SR)和萌发系数(GC)9个指标并进行主成分及隶属函数等分析,对水稻芽期耐寒性进行...

Comprehensive evaluation of cold tolerance and selection of cold tolerant evaluation indicators of rice at the germination stage

In order to screen cold-tolerant indexes at the germination stage of rice and establish a reliable mathematical evaluation model for the cold tolerance at the germination stage, 49 rice germplasm resources were selected in this study, and 9 indicators including germination rate(GR), germination potential(GP), relative germination rate(RGR), relative germination potential(RGP), germination index(GI), promptness index(PI), mean germination time(MGT), germination coefficient(GC)and seedling rate(SR)were measured. The principal components and membership functions were analyzed to comprehensively evaluate the cold tolerance of rice at the germination stage. The 49 rice varieties were divided into 5 grades according to their comprehensive evaluation values(D)of cold tolerance at the germination stage. Among them, the varieties with particularly strong cold tolerance(IRIS 313-11965, IRIS 313-8956 and IRIS 313-11038, D is ranged from 0. 790 to 0. 830), strong cold tolerance(IRIS 313-11944 and other 17 varieties, D is range from 0. 609 to 0. 745), moderate cold-tolerant varieties(IRIS 313-11049 and other 7 varieties, D is ranged from 0. 503 to 0. 576), weak cold-tolerant varieties(IRIS 313-11986 and other 13 varieties, D is ranged from 0. 364 to 0. 482), varieties with particularly weak cold tolerance(IRIS 313-10891 and other 9 varieties, D is ranged from 0. 187 to 0. 282). Stepwise regression analysis was used to obtain the optimal regression equation for cold tolerance during the germination stage of rice: D=0. 326+0. 020GI+0. 021SR-0. 028MGT+0. 025PI+0. 012GR+0. 137RGP. A total of 6 indicators were selected as follows: germination rate, relative germination potential, germination index, promptness index, mean germination time and seedling rate. These 6 indicators displayed significant impact on the cold tolerance of rice at the germination stage. In conclusion, under low temperature stress conditions, these 6 indicators can be used to quickly and accurately identify and evaluate the cold tolerance of rice varieties at the germination stage.