耐热水稻基因型的鉴定及相关生理学特征分析(英文)

Identification and physiological characterization of thermo-tolerant rice genotypes

对来自不同国家和地区的72个水稻品种在抽穗扬花期进行高温处理(40℃/35℃,14h/10h,12d),记录结实率,分析和耐热相关的生理学特征,并鉴定耐热水稻的基因型.2年的试验结果表明:高温对结实率有严重的伤害,且基因型间存在明显的差异;苗期高温处理显著降低了叶绿素含量(SPAD值)、株高、根长和生物量,且对敏感基因型的影响较耐热基因型大;同时,高温胁迫导致膜脂过氧化,表现为丙二醛含量增加和超氧化物歧化酶活性增强;与敏感基因型相比,耐热基因型的丙二醛含量增加较少,而超氧化物歧化酶活性增加较多;根据试验结果,春江06、密阳46和京系17为高耐热基因型,明恢63、Kasalath和IRAT4217为高热敏感基因型.

The experiments were conducted to identify thermo-tolerant rice genotypes and characterize physiological traits relevant to heat stress tolerance.Seventy-two rice genotypes were exposed to high temperature（40 ℃/35 ℃,14 h/10 h） for 12 d at heading stage,and floret fertility was examined.The similar results were obtained in the two years＇ experiments that there was a distinctly genotypic difference in floret fertility as affected by heat stress.When rice seedlings were exposed to heat stress,chlorophyll content（SPAD value）,plant height,root length,shoot and root biomass were dramatically reduced,with thermo-tolerant genotypes being relatively less affected than sensitive ones.Meanwhile,high temperature enhanced membrane lipid peroxidation,as expressed by malondialdehyde content and increased superoxide dismutase（SOD） activity.Thermo-tolerant genotypes had less and more increase in MDA content and SOD activity than sensitive ones under heat stress relative to the control,respectively.Accordingly the thermo-tolerant genotypes were identified,with genotypes CJ6,MY46 and JX17 being highly thermo-tolerant,MH63,Kasalath and IRAT4217 being very sensitive.