不同成熟度茶树叶片抗逆性生理指标差异

茶树以收获芽叶为主,叶片的生理特性和抗逆能力直接决定着茶树生长势和品质成分的形成。为研究茶树不同成熟度叶片生理变化规律,以2个茶树品种为研究对象,测定茶树新梢不同成熟度叶片丙二醛(MDA)、脱落酸(ABA)、水杨酸(SA)、脯氨酸(Pro)、可溶性糖(SS)含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,综合评价各成熟度叶片的生理特性和抗逆能力,并通过相关性分析、主成分分析简化茶树抗逆性评价指标。结果表明,不同成熟度叶片的MDA、SA、SOD和Pro由1芽2叶至老叶基本呈现增加的趋势,老叶的含量均显著高于其他成熟度叶片;仅ABA含量随着叶片成熟度的增加而降低;SS含量则呈现先增加后降低趋势,新梢3、4叶达到峰值,老叶最低。相关性分析表明,MDA与SA、Pro之间存在极显著或显著正相关。ABA与MDA、SOD、Pro、SA、CAT存在中度到高度负相关。7个茶树叶片抗逆性评价指标可简化为5个,即MDA、ABA、SA、SS和CAT,可应用于茶树抗逆性的鉴定,提高种质材料的筛选效率。

Camellia sinensis Leaves with Different Maturity: Physiological Indices of Stress Resistance

Camellia sinensis is mainly cultivated for its leaves, and the physiological properties and stress tolerance of leaves directly determine the growth vigor and quality composition of C. sinensis. The object of this study is to explore the physiological changes of different maturity leaves of C. sinensis. Taking 2 tea cultivars as test materials, the malonaldehyde (MDA), proline (Pro), soluble sugars (SS), abscisic acid (ABA), salicylic acid (SA), superoxide dismutase (SOD), catalase (CAT) of different maturity leaves were monitored, and correlation analysis, principal component analysis were applied to simplify the evaluation index of stress resistance of tea plant. The results were as follows: MDA, SA, SOD and Pro from one bud and two leaves to old leaves showed an increasing trend, their contents in old leaves were significantly higher than those in the other maturity leaves. Only ABA content decreased with the increase of maturity. The SS content first increased and then decreased with the maturity, whose maximum value emerged at the middle leaves (from 3rd to 4th). The correlation analysis indicated that MDA had significantly positive or remarkably and significantly positive correlation with Pro and SA. The ABA had middle and high negative correlation with MDA, SOD, Pro, SA, and CAT. The seven physiological indices of stress resistance of tea plant could be reduced to five, i.e., MDA, ABA, SA, SS and CAT, which could be applied to the evaluation of stress resistance of tea plant, thus to improve the screening efficiency of germplasm materials.