人工模拟水分胁迫对短葶山麦冬若干生理指标的影响

摘要

以盆栽的短葶山麦冬为材料,通过设置80％、65％、50％和35％土壤田间持水量(FC),研究土壤水分胁迫对短葶山麦冬碳、氮代谢若干生理指标的影响,探讨短葶山麦冬的水分适应性.结果表明,不同生育期短葶山麦冬叶片色素含量对水分胁迫响应规律不同.块根发生期,中度胁迫(50％FC)显著提高叶绿素a+ b(Chla+b)、叶绿素a(Chla)、叶绿素b(Chlb)及类胡萝卜素(Car)含量,重度胁迫(35％FC)降低了Chla+b、Chla、Chlb含量.胁迫后期,水分胁迫显著降低Chla、Chla +b及Car含量.块根膨大期之前,80％FC下叶片可溶性蛋白含量最高,但各处理间差异不显著,块根膨大期中度胁迫(50％FC)显著提高叶片可溶性蛋白含量.水分胁迫对叶片游离氨基酸含量影响因生育期而不同,至胁迫末期表现为随土壤含水量降低而减少.胁迫初期脯氨酸和可溶性糖含量各处理间差异不显著,随胁迫时间延长,中、重度胁迫显著提高脯氨酸和可溶性糖含量,有利于其抗旱.%The effects of water stress on the leaf physiological indexes of carbon and nitrogen metabolization of Liriope muscari (Dec-ne. ) Bailey under pot cultural condition were studied by controlling soil water content. Seedlings were subjected to 4 watering regimes, which were watered to 80%, 65% , 50% and 35% field capacity ( FC), respectively. Toe results showed that the response of chlorophyll content to water stress was different in different development stage. In tuber-bearing stage, moderate stress (50% FC ) increased the content of Chla + b, Chla, Chlb and Car significantly. Severe water stress (35%FC) decreased the content of Chla + b, Chla, and Car significantly. Water stress decreased the content of Chla, Chlb and Car significantly in the later stage. The soluble protein content was biggest but had no significant difference among the different treatments before tuber root expanding. Moderate stress increased the soluble protein content significantly in the tuber-root expanding stage. The response of free amino content to water stress varied in different development stage, and declined with the decreasing of soil water in the final stress stage. The content of praline acid and soluble sugar had no significant difference in the initial stage, while moderate and severe water stress increased the content of proline acid and soluble sugar significantly with the stress time, which contributed to the improvement of drought-resistant ability.