【摘要】 为验证春小麦叶片中灰分及其中主要矿质元素含量与Δ的关系,进行了3个处理的盆栽试验,即田间持水量(FC)为(45±5)%,(55±5)%和(75±5)%。测定了扬花期的蒸腾效率(地上部干物重/蒸腾水量)、旗叶Δ、灰分含量以及钾(K)、镁(Mg)、钙(Ca)含量。结果发现:不同基因型扬花期旗叶Δ13C有显著差异,在重度水分胁迫处理(T1,(45±5)%FC)条件下,旗叶中的灰分含量与(呈显著正相关。在中度水分胁迫处理(T2,(55±5)%FC),扬花期旗叶中的K的含量与(呈显著负相关;在T2和正常灌水处理(CK,(75±5)%FC)下,扬花期旗叶中Mg的含量与Δ13C呈显著正相关,蒸腾效率(TE)与Δ呈显著负相关。认为在充分供水及轻度水分亏缺条件下,Δ较好地反映了不同基因型的蒸腾效率;而在水分胁迫条件下旗叶中的灰分含量是Δ较好的替代指标;旗叶中K、Mg和Ca的含量在中度水分胁迫和正常供水条件下能够较好地预测Δ13C值。更多还原

【Abstract】 Carbon isotope discrimination(Δ) has been proposed as an indirect selection criterion for transpiration efficiency and grain yield in wheat.However,because of high cost for Δ analysis,attempts have been made to identify alternative screening criteria.Ash content(ma) has been proposed as an alternative criterion for Δ in wheat and barley.A pot experiment with three water treatments,i.e.(45±5)% FC,(55±5)% FC and(75±5)% FC was conducted and carbon isotope discrimination in flag leaves at anthesis(ΔLa),transpiration efficiency at anthesis stage,ash content and the concentrations of potassium(K),magnesium(Mg) and calcium(Ca) were measured in flag leaves of 10 genotypes of spring wheat(Triticum aestivum L.) to study the correlations of Δ,mineral composition in flag leaf and transpiration efficiency.The results showed that there was a significant difference in flag leaf Δ of wheat genotypes used in this study.Significant and positive correlations were found between Δ and ma in severe drought treatment(T1).Δ was negatively associated with K concentration in medium drought treatment(T2) and positively associated with Mg concentration in T2 and well watered treatment(T3).There were negative correlations between Δ and transpiration efficiency(TE) in T2 and T3.These results suggested that Δ is a useful trait as a selection criterion for genotypic improvement in transpiration efficiency under well watered or medium drought stress conditions,while ma is a possible alternative criterion of Δ in flag leaves especially in stressed environments.K,Mg and Ca contents in leaves under medium water stress or well watered conditions might be new predictive criteria of Δ.更多还原