Genetic Analysis of Heading Date of Japonica Rice Cultivars in Southwest China

Heading date of 26 native japonica rice cultivars in southwest China was investigated,and their basic vegetative growth(BVG),photoperiod-sensitivity(PS) and temperature-sensitivity(TS) were analyzed under artificial short-day and natural long-day conditions in Nanjing,as well as artificial high-temperature and natural low-temperature conditions in winter in Hainan.The results showed that the PS and TS varied among different cultivars.The BVG of all the japonica cultivars was well situated,but differed within cultivars.Regression analysis showed a significant correlation between heading date and PS,indicating that PS was the main factor affecting heading date of japonica cultivars in southwest China.Genetic analysis was conducted on these 26 cultivars using a set of heading date near isogenic lines as test lines.All the japonica cultivars carried the dominant early-heading gene Ef-1 or Ef-1t,and most of these cultivars carried the dominant photoperiod sensitivity allele E1 or E1t,the PS of which was slightly weaker than E1.For the Se-1 locus,these cultivars mainly carried recessive photoperiod insensitivity gene Se-1e.In addition,the PS of 22 japonica cultivars could be repressed or weakened by the recessive allele hd2,inhibiting the expression of E1 and Se-1.These results indicated that the genotypes of heading date determined different PS and well situated BVG in japonica rice cultivars in southwest China.

The Distribution of Japonica Rice Cultivars in the Lower Region of the Yangtze River Valley is Determined by Its Photoperiod-sensitivity and Heading Date Genotypes

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 E1t. Most of the MMM, LMM and MML types carry the insensitive allele e3, while EML types have either E3 or E3t. At Se-1, MMM and LMM types have Se-1e, some EML types have Se-1e and others Se-1n, while the MML types are mostly Se-1n. 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.

Genotypes of Heading Date of Middle Indica Rice in the Mid-lower Region of the Yangtze River

中间的 indica 栽培变种在中间被种降低长江的区域。有这些栽培变种的混合联合有一个高产潜力但是 late-transgressive-segregants 的存在限制杂种优势的进一步的利用。为了理解标题的基因基础，在这些中间的成熟栽培变种标明日期，我们在长、短的天条件下面用很多出发日期 isogenic 执行了 10 典型中间季节的栽培变种的基因分析。结果显示出那 Teqing， 752， CDR22， Bo B， 9311 并且 II-32B 带二个光周期敏感基因 E1 或 Se-1 和 E3，和 Teqing， 752 并且 CDR22 当时，带主导的早标题的基因 Ef-1 Bo B， 9311 并且 II-32B 带后退的迟了标题的基因 ef-1。在 Guichao 2 上基于礼品和以前的工作的调查结果， Minghui 63 ，南京 11 并且 Pei'ai64S ，所有这些中间的 indica 栽培变种带了后退的等位基因 hd2 ，这被结束，它能禁止 E 或 Se-1 的表示，并且他们为在进化的一个长时期期间领导日期形成了遗传型的合理联合。为在米饭耕作和扩展上领导日期的遗传型的不同联合的效果被讨论，并且混合中间的 indica 栽培变种的宽广适应性的基因基础被分析。

Genotyping the Heading Date of Male-Sterile Rice Line II-32A

II-32A，精英米饭(Oryza sativa L.) 的男性无菌的线，广泛地在中国为杂交稻种子的生产被使用了。在到后者父母的大多数联合 usingII-32A 表演 transgressive 继承或类似的标题日期，而是到为领导时间的主要基因的第 11-32Awi 尊重的遗传型是未知的。这在繁殖和混合采种限制这根无菌的线的进一步的利用。用很多个主要基因标题， dateisogenic 排队，标题日期 QTL near-isogenic 排队，我们遗传上在 bothlong 天和短天的条件下面分析了 II-32B。我们证明 II-32B 带二光周期敏感的基因， E1 andE3，后退的迟了标题的基因， ef-1，和光周期敏感的等位基因， Se-1u。另外，我们为 E1 或 Se-fand 在 II-32B 识别了一个后退的禁止者另外的修改 photoperiod-sensitivegenes。II-32A 的标题日期体质决心是 E_1e_2E_3Se-1uef-1i-Se-1。