There are generally four recognized classes of japonica rice cultivars grown in the lower region of the Yangtze River valley. The geographical distribution of the four classes is latitude-dependent. Variation for head...There are generally four recognized classes of japonica rice cultivars grown in the lower region of the Yangtze River valley. The geographical distribution of the four classes is latitude-dependent. Variation for heading date （HD） among 29 japonica rice cultivars grown in the lower region of the Yangtze River valley and belonging to the four classes was characterized, and their sensitivity to variations in photoperiod and temperature was analyzed. All of the cultivars were sensitive to both photoperiod and temperature. A regression analysis showed that HD is closely correlated with photoperiod sensitivity （PS）. The PS of the four classes increased gradually from the medium maturing middle （MMM） types, through the late maturing middle （LMM） and early maturing late （EML） types to the medium maturing late （MML） types. Crosses with tester lines established that almost all of the cultivars carry the dominant early-heading allele at Ef-1, the photoperiod insensitive allele e2 and the PS alleles E1 or E1^t. Most of the MMM, LMM and MML types carry the insensitive allele e3, while EML types have either E3 or E3^t. At Se-1, MMM and LMM types have Se-1^e, some EML types have Se-1^e and others Se-1^n, while the MML types are mostly Se-fn. The PS of some MMM, LMM and EML types is reduced by the presence of hd2. These results show that the distribution of the four rice cultivar classes from high latitude to low latitude regions depended on a gradual increase in PS, which is mainly determined by its HD genotypes.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.30871497)the National High Technology Research and Development Program of China(Grant No.2009AA101101)the Program of Introducing Talents of Discipline to University(Grant No.B08025)
基金Supported by the National Hi-Tech Research and Development Programof China (2006AA100101,2006BAD01A01-5 and 2006BAD13B01)the National Natural Science Foundation of China (30871497)+2 种基金Jiangsu Scienceand Technology Development Program (BG2006301)Jiangsu Agricultural Germplasm Gene Pool Program (sx(2008)g08)the 111 Project (B08025)
文摘There are generally four recognized classes of japonica rice cultivars grown in the lower region of the Yangtze River valley. The geographical distribution of the four classes is latitude-dependent. Variation for heading date （HD） among 29 japonica rice cultivars grown in the lower region of the Yangtze River valley and belonging to the four classes was characterized, and their sensitivity to variations in photoperiod and temperature was analyzed. All of the cultivars were sensitive to both photoperiod and temperature. A regression analysis showed that HD is closely correlated with photoperiod sensitivity （PS）. The PS of the four classes increased gradually from the medium maturing middle （MMM） types, through the late maturing middle （LMM） and early maturing late （EML） types to the medium maturing late （MML） types. Crosses with tester lines established that almost all of the cultivars carry the dominant early-heading allele at Ef-1, the photoperiod insensitive allele e2 and the PS alleles E1 or E1^t. Most of the MMM, LMM and MML types carry the insensitive allele e3, while EML types have either E3 or E3^t. At Se-1, MMM and LMM types have Se-1^e, some EML types have Se-1^e and others Se-1^n, while the MML types are mostly Se-fn. The PS of some MMM, LMM and EML types is reduced by the presence of hd2. These results show that the distribution of the four rice cultivar classes from high latitude to low latitude regions depended on a gradual increase in PS, which is mainly determined by its HD genotypes.
