杂交水稻孕穗期和开花期耐冷性鉴定指标研究

Identification Index for Cold Tolerance of Hybrid Rice at the Booting and Flowering Stage

以人工气候箱和大田试验相结合的方法对18个杂交水稻组合的孕穗期和开花期进行耐冷性鉴定。结果表明,低温处理后的相对结实率能够反映不同品种的耐冷性差异,可作为耐冷鉴定的主要评价指标;相对结实率与相对株高和相对着粒密度呈极显著的正相关,相关系数在开花期分别为0.4653和0.4182,孕穗期分别为0.4951和0.7010,可作为耐冷性鉴定评价辅助指标;相对结实率与相对包颈长差呈显著负相关(开花期r1=-0.2609,孕穗期r2=-0.2265),相对包颈长差也可作为一个参考指标。经逐步多元回归分析表明,相对株高、相对着粒密度和相对包颈长差对相对结实率影响较大。

18 hybrid rice combinations were identified in the air-condition room and field at the booting and flowering stages to evaluate their cold tolerance. The results indicate that the relative setting rate after cold treatment can reflect difference of different combinations in cold tolerance, which can be used as the main identification index for cold tolerance. There are the very significant positive relation between the relative setting rate and relative plant height, relative grain density, and the relative coefficients between setting rate and relative plant height are 0. 4653 at the flowering stage and 0. 4951 at the booting stage and the relative coefficients between the relative setting rate and relative grain density are 0. 4182 at the flowering stage and 0. 7010 at the booting stage respectively, which can be used as the secondary identification index for cold tolerance. There is a very significant negative relation between the relative setting rate and gap of relative panicle enclosed length （r1 = 0. 2609^＊ at the flowering stage and r2 =0. 2265^＊ at the booting stage）, which can be used as the reference index for identifying cold tolerance also. The results from regression analysis show that the relative plant height, relative grain density and gap of relative panicle enclosed length affect the relative setting rate greatly.