旱地春小麦籽粒碳同位素分辨率及冠层温度与产量的关系

Relationships among Grain Carbon Isotope Discrimination,Canopy Temperature and Yield in Spring Wheat under Drought Conditions

[目的]探讨小麦冠层温度和叶绿素含量替代碳同位素分辨率(CID)进行抗旱育种的可靠性。[方法]以抗旱性不同的5个春小麦品种为材料,测定正常灌溉和干旱处理的籽粒CID、开花期与灌浆中期的冠层温度以及旗叶叶绿素含量指数,并分析这些指标与籽粒产量的关系。[结果]在干旱、灌水条件下,籽粒CID均与产量显著正相关(P≤0.01);灌浆中期的冠层温度在干旱条件下与籽粒CID显著负相关(P≤0.05),但在灌水条件下与后者相关不明显,开花期的冠层温度在2种条件下与籽粒产量及CID均无明显相关;在2种处理下,旗叶叶绿素含量与CID均无明显相关。[结论]灌浆中期的冠层温度仅在干旱条件下可以替代籽粒CID进行抗旱品种选育,而在干旱和灌水条件下开花期冠层温度和旗叶叶绿素含量均不能用作籽粒CID的替代指标。

[Objective] The aim was to study the reliability of using canopy temperature and chlorophyll content to replace carbon isotope discrimination （CID） in wheat breeding for drought tolerance.[Method] Five spring wheat （Triticum aestivum L.） cultivars,differing in drought tolerance,were planted in drought and irrigated conditions to measure grain CID,canopy temperature during anthesis and mid-filling stage and chlorophyll content of flag leaves.The correlation among those items and grain yield were evaluated.[Result] Grain yield and CID were related to a significant positive correlation in drought and irrigated conditions.Canopy temperature during mid-filling stage was related to a significant negative correlation to CID in drought,while no significant correlation in irrigated conditions.Canopy temperature during anthesis had no significant correlation with CID in both conditions,so was chlorophyll content of flag leaves.[Conclusion] In wheat breeding for drought tolerance,canopy temperature during mid-filling stage can be used to replace grain CID in drought conditions,while canopy temperature during anthesis and chlorophyll content of flag leaves can＇ t be used to replace CID neither in drought nor in irrigated conditions.