水稻品种耐热性与相关生化指标的关联分析

研究高温胁迫下水稻生化特性变化及其与品种耐热性的关系,可为水稻耐热性育种、耐热品种的鉴定和热害后补偿栽培技术研究提供依据。采用人工智能温室对水稻幼穗分化期到抽穗开花期进行高温处理,研究了高温胁迫对水稻叶片叶绿素、可溶性糖、脯氨酸、可溶性蛋白等6项生化指标含量变化的影响,对各品种生化指标变化与热敏感指数进行多元回归分析筛选水稻耐热性鉴定指标。结果表明,高温胁迫后,水稻叶片叶绿素、可溶性糖以及内源多胺含量在3个处理阶段均呈下降趋势,但耐热品种下降幅度明显小于热敏感品种;脯氨酸和丙二醛含量变化趋势与之相反,耐热品种脯氨酸含量上升幅度明显大于热敏感品种,而丙二醛含量上升幅度则明显小于热敏感品种;高温处理7 d后,叶片可溶性蛋白含量上升,处理14 d和21 d后呈逐渐下降趋势。高温胁迫后,叶绿素、可溶性糖、脯胺酸、可溶性蛋白、丙二醛以及内源多胺等含量变化与水稻耐热相关性存在较大差异。叶绿素、可溶性糖、脯氨酸、可溶性蛋白、丙二醛以及内源多胺含量可以作为水稻幼穗分化期到抽穗开花期耐热性鉴定的生化指标。

Correlation Analysis Between High Temperature Resistance and Pertinent Biochemical Indexes Among Different Rice Varieties

The aim of this study was to investigate the correlation between certain stress-related biochemical indexes and heat resistance in rice and provide guidlines for identifying heat resistance germplasms and for breeding heat resistance varieties as well as for cultivation prac-tice.Different rice varieties were treated with high temperature in a temperature controllable greenhouse and the contents of chlorophyll,solu-ble sugar,proline,soluble protein and other indexes in leaves were measured.The effect of high temperature stress on those biochemical in-dexes was analyzed using multiple regression analysis to screen for useful biochemical indexes identifying heat resistance from young panicle differentiation stage to heading flowering period of rice.After high temperature stress,the contents of chlorophyll,soluble sugar and endoge-nous polyamines were all decreased in leaves of all varieties tested in all three heat treatments.However,the heat resistant varieties showed a lower decrease than heat sensitive varieties.Meanwhile,the contents of proline and malondialdehyde were increased.Higher proline levels were observed in heat resistant varieties than that in heat sensitive varieties while the malondialdehyde levels were lower in heat resistant va-rieties.The content of soluble protein was increased with high temperature stress after seven days,and decreased with high temperature stress after 14 days and 21 days.The relationships between content changes of chlorophyll,soluble sugar,proline,soluble protein,malondialdehyde and endogenous polyamines and heat resistance were significantly different.The change of chlorophyll,soluble sugar,proline,soluble protein,malondialdehyde and endogenous polyamines can be used as biochemical indexes to identify heat resistance of rice from young panicle dif-ferentiation stage to heading flowering period.