人工模拟水分胁迫条件下小麦幼苗抗旱性鉴评指标的分析

为了明确小麦幼苗抗旱性鉴定评价的最佳时期和有效指标,以小麦加倍单倍体(Doubled haploid,DH)群体的150个株系为材料,采用模拟干旱胁迫法,研究了水分胁迫及复水条件下,幼苗叶片相对含水量、叶片相对电导率、根冠比、根干重和最大根长等五个抗旱相关性状的动态变化和遗传力,分析了各性状及其与平均隶属函数值之间的关系.结果表明,在水分胁迫72 h(WS72)和复水24 h(RW24)时,基因型之间的性状变异范围较大,是进行幼苗抗旱性鉴定评价的较好时期;平均隶属函数值不仅受各性状的直接影响,还受到性状之间交互作用的影响.在选择适当的与抗旱性关系密切性状的基础上,估算平均隶属函数,作为评价抗旱性的综合指标,可能是进行作物抗旱性综合评价的有效途径.

Analysis on Criteria for Drought Tolerance Evaluation of Wheat Seedlings under Artificially Simulated Water-stress Conditions

The purpose of the present research is to select feasible time points and criteria for drought tolerance evaluation of wheat seedlings under artificially simulated water-stress conditions.A double haploid(DH) population with 150 lines,derived from two common wheat varieties Hanxuan 10 and Lumai 14,was used to study the dynamic changes and heritabilities of seedling traits related to drought tolerance,such as leaf relative water content(RWC),leaf relative conductance rate(RCR),root-shoot ratio(RSR),root dry weight(RDW) and maximum root length(MRL) under artificially simulative water-stress and rewater conditions.The mean membership function values of the traits were estimated in water-treated time course.Correlativity analysis and path analysis were conducted to study the relationship among the five traits and the mean membership function.The results showed that there were significant variations among different genotypes at 72 h after water-stress and 24 h after rewatering.Therefore,they were considered as good time points to evaluate the drought tolerance in wheat seedlings.The mean membership function was determined not only by the direct effects of the subjected traits,but was also by their interaction effects.Based on the reasonable traits related to drought tolerance,the mean membership function was accounted as an efficient and integrated criteria for evaluating the drought tolerance of the crops.