不同土壤水分含量对黄花风铃木幼苗生长和生理的影响

Effects of Different Soil Water Content on Growth and Physiology of Tabebuia chrysantha Seedlings

【目的】研究不同土壤水分含量对黄花风铃木幼苗生长指标和生理指标的影响,为其日常养护管理和扩大在广西的引种范围提供参考依据。【方法】以1年生黄花风铃木幼苗为研究对象,测定其在培养基质相对含水量100%、80%、60%和40%处理下的生长和生理指标,分析其对不同土壤水分含量的适应能力。【结果】随着培养基质水分含量的减少,黄花风铃木幼苗的株高增量、地上部生物量和叶绿素a、叶绿素b、类胡萝卜素、叶绿素a+b、可溶性糖、可溶性蛋白含量及过氧化物酶(POD)活性均呈先上升后下降的变化趋势,地径增量、总根长、根尖数、地下部生物量和单株生物量均呈上升趋势,丙二醛(MDA)含量呈先降低后升高的变化趋势。其中,土壤相对含水量60%处理下幼苗的株高增量、地径增量、根尖数、地上部生物量、地下部生物量、单株生物量及叶绿素a、叶绿素b、类胡萝卜素、叶绿素a+b、可溶性糖、可溶性蛋白、MDA含量和POD活性均显著高于土壤相对含水量100%处理(P<0.05,下同)。相关性分析结果表明,黄花风铃木幼苗的株高增量、单株生物量和可溶性蛋白含量间及地径增量、总根长、根尖数和地下部生物量间呈显著或极显著相关(P<0.01,下同);地上部生物量及叶绿素b、类胡萝卜素、可溶性糖和可溶性蛋白含量间呈显著或极显著相关;叶绿素a、叶绿素b、类胡萝卜素、叶绿素a+b、可溶性糖、可溶性蛋白和MDA含量间呈显著或极显著相关。【结论】培养基质不同水分含量对黄花风铃木幼苗生长和生理指标的影响存在差异,其中在土壤相对含水量为60%时株高增量、地上部生物量及叶绿素a、叶绿素b、类胡萝卜素、叶绿素a+b、可溶性糖、可溶性蛋白含量和POD活性最佳,MDA含量最低,最适宜黄花风铃木幼苗生长发育。

【Objective】The effects of different soil water contents on the growth and physiological indexes of Tabebuia chrysantha seedlings were studied in order to provide a reference basis for its daily maintenance and management and expanding the scope of introduction in Guangxi.【Method】Taking the one-year-old T.chrysantha seedlings as the research objects,its growth and physiological indexes were measured under the culture matrix with soil water holding capacity of 100%,80%,60%and 40%field capacity of culture medium,and its adaptability to different soil water contents was analyzed.【Result】With the decrease of water content in culture matrix,plant height increased,aboveground biomass,Chl a content,Chl b content,carotenoids content,Chlorophyll content,soluble sugar content,soluble protein content and POD activity of T.chrysantha seedlings increased first and then decreased,ground diameter increased,total root length,root tip,underground biomass and biomass all increased,MDA content decreased first and then increased.The results showed that the plant height increased,ground diameter increased,root tips,aboveground biomass,underground biomass,biomass,Chl a content,Chl b content,carotenoids content,chlorophyll content,soluble sugar content,soluble protein content,MDA content,and POD activity in seedlings growing on the soil with 60%water holding capacity were significantly higher than those on the soil with 100%water holding capacity(P<0.05,the same below).Correlation analysis results showed that there was a significant or extremely significant correlation(P<0.01,the same as below).Among the plant height increased,biomass,soluble protein content,ground diameter increased,total root length,root tips,and underground biomass of T.chrysantha seedlings.There was a significant or extremely significant correlation among the aboveground biomass,Chl b content,carotenoids content,soluble sugar content,and soluble protein content;There was a significan or extremely significant correlation among the Chl a content,Chl b content,carotenoids content,chlorophyll content,soluble sugar content,soluble protein content,and MDA content.【Conclusion】There were differences in the effects of different water content of culture matrix on the growth and physiological indexes of T.chrysantha seedlings,in which the plant height increased,aboveground biomass,Chl a content,Chl b content,carotenoids content,chlorophyll content,soluble sugar content,soluble protein content and POD activity were the best and MDA content was the lowest when the water content in the field was 60%.Therefore,when the soil relative water content is 60%in culture matrix,soil water content is the most suitable for the growth and development of T.chrysantha seedlings.