孕穗期水稻叶片生理性状与抗旱性相关分析

研究以不同类型的水稻与旱稻品种为试验材料,比较了干旱胁迫下孕穗期各稻作类型与典型水稻叶片水势(压力势)、中脉粗、叶肉厚和叶片相对含水量差异。对水旱处理条件下各观测性状指标与产量抗旱指数、孕穗期生物量抗旱指数和收获期生物量抗旱指数进行相关分析,结果表明:1)干旱胁迫条件下叶片水势(压力势)、中脉粗、叶肉厚和叶片相对含水量差异在耐旱稻作品种与典型水稻间存在显著差异,可以作为鉴定稻作品种抗旱性指标,但是少数抗旱材料易被遗漏;2)叶片水势、叶肉厚在干旱胁迫下与干物质合成与积累有关,且叶片水势与最终产量形成有一定关联;3)育种工作中叶片水势和叶肉厚可作为主要筛选指标,其他试验指标可用于辅助筛选鉴定,综合判断材料的抗旱性和生产应用价值。

Relationship of drought tolerance with rice leaf physiology under booting stage

Enhancing the drought tolerance of rice variety is an important technology and strategy to food safety of China.Improvement and innovation of rice drought tolerance index is the key to improve drought tolerance rice variety and breeding technology.In this research,different rice varieties were used to identify physiological traits associated with drought tolerance.The major traits were leaf water pressure potential,leaf midrib coarse,mesophyll thickness and relative water content,the difference between typical rice and the other rice type under drought environment.Difference between two treatments of drought and flooded was studied.Correlation between tested traits and yield drought resistant index,booting stage biomass drought resistant index,harvest stage biomass drought resistant index was analysed.The result showed that leaf water pressure potential,leaf midrib coarse,mesophyll thickness and relative water content could be used as index for drought tolerance identification in rice,though this method could miss some drought tolerant materials.The leaf water pressure potential,mesophyll thickness were correlated with dry matter production and accumulation,and consequently with the final yield.Therefore,the leaf water pressure potential,leaf midrib coarse was recommended as main index,complemented with other index in rice breeding for drought tolerance.