铬胁迫下不同品种小麦萌发和内源激素的变化

Variations in Germination and Endogenous Hormone Contents of Wheat Cultivars under Cr Stress

采用K2(CrO4)3溶液,设5个浓度,对3种不同抗性的小麦品种(新麦19、矮抗58和豫麦18)进行萌发期胁迫处理,研究了幼苗的发芽势、发芽率、根长、芽长及内源激素含量的变化.结果表明:(1)随着铬浓度的增加,发芽势、发芽率和芽长均基本呈"先升后降"趋势;(2)同一浓度铬处理下,发芽率、发芽势和芽长从大到小的顺序依次为:新麦19、矮抗58、豫麦18,根长从大到小的顺序为:豫麦18、新麦19、矮抗58;(3)150mgL-1的铬胁迫下,IAA与ABA在小麦幼苗、幼根中含量降低,在籽粒中含量升高,其中新麦19籽粒和根芽中ABA含量均高于其他品种的;(4)不同浓度铬胁迫下,IAA/ABA值在新麦19中最低,变化幅度最小,新麦19表现出较强的抵抗铬胁迫能力.

Chromium（Cr） affects the growth of wheat plants（Triticum aestivum L.） badly.There are reports about the restrictive function of Cr to wheat growth and development.Understanding the mechanism of Cr resistance of wheat cultivars is of importance to wheat production and breeding.In this experiment,three wheat varieties Xinmai 19,Aikang 58 and Yumai 18 were used as experimental materia1.The seeds of each cultivar were water-cultivated at Cr concentrations of 0,25,50,100,150 mg L^-1 to investigate the effect of Cr on germination energy, germination percentage, root length, shoot length and the endogenous hormones contents in roots and shoots at germination stage. The results showed： （1） With the increase in Cr concentration, the germination energy, germination percentage, root length and shoot length increased first and declined then; （2） Under the same Cr concentration treatment, the characteristics of germination energy, germination percentage and shoot length were found in an order： Xinmai 19 〉 Aikang 58 〉 Yumai 18, and the root length： Yumai 18 〉 Xinmai 19 〉 Aikang 58; （3） The treatment with 150 mg L^-1 chromium caused the decrease in IAA and ABA contents in roots and shoots, and the increase in seeds. Compared with the other two wheat varieties, Xinmai 19 showed a higher ABA content in seeds, roots and shoots; （4） The ratios of IAA/ABA of Xinmai 19 were lower than those of the other two varieties under Cr stress. Xinmai 19 had a stronger ability to resist the Cr stress than the others. Fig 3, Tab 1, Ref20