重庆地区野生草本植物叶表皮蜡质的季节性变化  

Seasonal variations of leaf cuticular wax in herbs widely distributed in Chongqing

作　　者：高建花 和玉吉 郭娜[1] 郭彦军[1] 

机构地区：[1]西南大学农学与生物科技学院,重庆400716

出　　处：《草业学报》2016年第1期134-143,共10页Acta Prataculturae Sinica

基　　金：国家自然科学基金(31270450);中央高校基本科研业务费专项(XDJK2014B002)资助

摘　　要：本研究以重庆地区四季或三季均有分布的9种野生草本植物为对象,分析了叶表皮蜡质化学组分及含量、正构烷烃、正构脂肪酸和初级醇的分布特征及其平均碳链长度和碳优势指数,探讨了季节变化与叶表皮蜡质的关系。结果表明草本植物叶表皮蜡质组分及含量存在显著种间差异,如蜡质总量最高的苦苣菜,四季平均18.42μg/cm2,而最低的马兰平均只有0.83μg/cm2。苦苣菜、葎草和灰绿藜以脂肪酸和初级醇为主要蜡质组分,其余植物均以烷烃为主要组分。多数植物叶表皮蜡质含量从春季至秋季,整体出现先减小,到冬季增大的趋势,且在夏季蜡质总含量相对其他季节最低。除葎草在冬季、灰绿藜在春季以C27、C29和C31为优势峰外,其余植物在不同季节均以C29、C31和C33为优势峰,且不随季节改变而变化。多数植物正构烷烃总碳优势指数呈现从春季至秋季先下降,冬季再增大的趋势;而正构脂肪酸和初级醇平均碳链长度,多数植物夏季大于冬季。综合分析认为,草本植物通过调节叶表皮蜡质的沉积、改变主要蜡质组分的平均碳链长度及奇/偶碳的相对含量,提高对周边环境的适应性。Cuticular wax covers the outmost leaf surface and plays an important role in protecting plants from biotic and abiotic stress.The composition and amount of cuticular wax varies with environmental conditions.In this study,nine widely distributed herbs in Chongqing have been seasonally analyzed for the amounts of total cuticular wax and for variations in its composition.Analysis has been undertaken of the distributions of n-alkanes,n-alkanoic acids and primary alcohols,and their average chain length(ACL)and carbon preference index(CPI).Five plant species were observed in four seasons:Solanum nigrum,Conyza canadensis,Oplismenus undulatifolius,Calystegia hederacea and Sonchus oleraceus.Four species were observed in three seasons:Kalimeris indica,Plantago asiatica,Humulus scandens and Chenopodium glaucum.The results showed that the amount of total cuticular wax and its composition varied by plant species,with the highest total cuticular wax in Sonchus oleraceus(18.42μg/cm2)and the lowest in Kalimeris indica(0.83μg/cm2).The leaf cuticular wax in Sonchus oleraceus,Humulus scandens and Chenopodium glaucum was dominated by n-alkanoic acids and primary alcohols,whereas that in the other species was dominated by n-alkanes.In most plant species,total cuticular wax reduced from spring to autumn and then increased in winter,with the lowest levels in summer.The predominant carbons of n-alkanes in most plant species were C29,C31 and C33,except for Humulus scandens in winter and Chenopodium glaucumin spring,where C27,C29 and C31predominated.The CPI of n-alkanes in most plant species reduced from spring to autumn and then increased in winter,whereas the ACL of n-alkanoic acids and primary alcohols in most plant species was higher in summer than winter.Overall,seasonally distributed herbs might adapt to changing environments by adjusting wax deposition on leaves,altering the average chain length of the main cuticular wax compositions and the relative contents of even and odd numbered carbons.

关 键 词：草本植物 表皮蜡质 季节 重庆 适应性 

分 类 号：Q944.3[生物学—植物学]