水稻品种耐旱性鉴定的形态学评价指标研究

水稻耐早性鉴定是选育耐早水稻品种的前提。以22个水稻、陆稻和早稻品种为材料,研究了在干旱胁迫条件下,不同品种(组合)幼苗反复干旱存活率、播抽历期(日数)、株高、单穗重、着粒数、实粒数、结实率和千粒重等方面的变化趋势。苗期耐旱性鉴定中,采用幼苗反复干旱存活率,对苗期耐旱性进行评价,全生育期耐旱鉴定中,通过多重相关分析和产量结构分析,筛选出播抽历期(日数)、株高和单穗重3个与产量形成关系最密切因素的干旱胁迫指数,构成综合耐早指数,采用综合耐旱指数作为评价水稻品种全生育期耐旱性的指标,最后提出了苗期耐旱性鉴定和全生育期耐旱性鉴定的分级标准。

On Phenotypic Evaluation Index of Drought Tolerance in Rice

Rice drought tolerant evaluation is the basis for the breeding of the drought tolerant rice. Researches focused on the changing trends of different varieties' ( compositions' ) seedling under drought stress in the following aspects: survivor percentage of seedling in repeated drought, days to heading, plant height, single panicle weight, spikelets per panicle, grains per panicle, setting percentage, 1000 - grain weight, etc. Research materials are 22 rice varieties (Oryza Saliva . L), including water - rice, upland rice and dry rice. The drought tolerant evaluation at seedling stage adopted the survivor percentage of seedling in repeated drought. The drought tolerant evaluation at full stage selected three drought stress indexes, ie. days to heading, plant weight, single panicle weight, which are most closely related to the rice yield component, through multiple correlation analysis and yield components analysis. The three indexes composed the Rice Comprehensive Tolerance Index (RCTT). RCTI constructed the rice Evaluation Index (EI) at full stage. At last, the score standard of drought tolerance in rice at seedling and full stage were developed.