长林4号油茶幼苗对低温胁迫的生理响应

胡倩 裴云霞 倪天虹 耿若楠 张娟娟 余金金 杜克兵 周忠诚

摘 要： 為探究油茶幼苗对低温胁迫的生理生化响应机制，本研究以湖北省主栽油茶品种长林4号的2 a生幼苗为试验材料，研究了其表型、叶片气体交换参数以及相关生理指标对低温胁迫（4 ℃和-4 ℃）的响应。结果表明：①低温胁迫显著影响了长林4号油茶幼苗的形态特征，使嫩茎和叶片出现不同程度的萎蔫和失水症状，并且-4 ℃处理比4 ℃处理植株受损程度更严重。②低温胁迫显著降低了油茶叶片的气体交换参数（Pn、Gs、Tr、RWUEi）值，恢复期间其值仍持续下降，且-4 ℃处理的抑制作用显著强于4 ℃处理。③低温胁迫虽然降低了油茶叶片的SPAD值，但未达到显著水平。④低温胁迫显著提高了油茶叶片中的MDA、Pro和可溶性糖含量。恢复期间，4 ℃处理的MDA和Pro含量略有下降，而可溶性糖含量仍继续增加;-4 ℃处理的MDA和可溶性糖含量略有下降，Pro含量仍继续增加。（5）低温胁迫显著影响了油茶叶片中的抗氧化酶活性。随着胁迫时间的延长，SOD和POD活性持续上升，而CAT活性则先上升后下降，并且-4 ℃处理的上升幅度明显高于4 ℃处理;恢复期间，抗氧化酶活性均有不同程度的降低。

关键词： 油茶;低温胁迫;表型;生理生态特征

中图分类号：S794.4   文献标识码：A   文章编号：1004-3020（2020）06-0005-08

Abstract： In order to explore the physiological and biochemical response mechanism of C.oleifera seedlings to low temperature stress，this experiment took the 2-year-old seedings of C.oleifera‘Changlin4 as the experimental material to study the response of its phenotype、leaf gas exchange parameters and related physiological indicators under cold stress （4 ℃and -4 ℃）.The results showed that： ① Cold stress significantly affected the morphological characteristics of C.oleifera ‘Changlin4，causing wilting and water loss symptoms of the young stems and leaves in different degrees，and the degree of plant damage was more serious under -4 ℃ treatment than under 4℃ treatment.② Cold stress significantly reduced the values of gas exchange parameters （Pn、Gs、Tr、RWUEi） in the leaves of C.oleifera，which continued to decline during the recovery period，and the inhibition effect of -4 ℃ treatment was significantly stronger than that of 4 ℃.③ Although cold stress reduced the SPAD value of C.oleifera，it did not reach a significant level.（4） Cold stress significantly increased the content of MDA，Pro and soluble sugar in the leaves of C.oleifera.During the recovery period，the MDA and Pro content of 4 ℃ treatment decreased slightly，while the soluble sugar content continued to increase;the MDA and soluble sugar content of -4 ℃ treatment decreased slightly，while the Pro content continued to increase.（5） Cold stress significantly affected the activity of antioxidant enzymes in the leaves of C.oleifera.With the extension of stress time，SOD and POD activities continued to increase，while CAT activities first increased and then decreased，and the increase of -4 ℃ treatment was significantly higher than that of 4 ℃;during the recovery period，the activity of antioxidant enzymes decreased in varying degrees.

Key words： Camellia oleifera;cold stress;phenotype;eco-physiological characteristics

油茶Camellia oleifera是山茶科Theaceae山茶属Camellia中油脂含量较高且具有经济价值的一类植物的总称，被誉为“东方橄榄油”[1]。油茶在中国已经有2000多年的栽培历史，其适应能力强，经济价值高，是一种常绿阔叶的经济树种[2]。截止2018年，中国现有油茶林已达到436.67万hm2，主要分布在江西、湖南、浙江、福建、广西等省区[3-4]。……