摘要
【目的】山茶的花型和花色丰富、花期长,其耐热性日益受到关注,筛选合适的评价方法和指标可为山茶属植物耐热性鉴定、种质发掘和新品种选育提供理论依据。【方法】以耐热性较强的单体红山茶和‘串花瀑布’为对照,7个自育束花茶花新品种为试验对象,采用瓶插方法,在短期(5 h)和长期(7 d)高温(42℃/35℃)处理后,考察各品种形态及光合生理标指标的变化,并综合评价其耐热性。【结果】(1)‘垂枝粉玉’和‘串花瀑布’在高温胁迫下叶绿素含量、类胡萝卜素含量、叶绿素a/b、净光合速率(Pn)和气孔导度(Gs)均上升,PSⅡ最大光化学效率(F_(v)/F_(m))、PSⅡ潜在活性(F_(v)/F_(o))和电子传递速率(ETR)维持在较高水平,且长期高温胁迫后均未出现热害。‘金叶粉玉’、‘上植华章’和‘玫瑰春’在高温胁迫下Pn和Gs均显著降低,而Ci升高,‘金叶粉玉’和‘上植华章’的F_(v)/F_(m)、F_(v)/F_(o)和ETR均大幅降低,且长期高温胁迫后出现较严重热害或死亡。(2)通过主成分分析将15个单项指标换算成4个独立的综合指标,累计贡献率可达90%;短期高温时以叶绿素含量、类胡萝卜素含量、叶黄素含量的综合权重值较高,长期高温时以叶绿素a/b、F_(v)/F_(m)、光化学淬灭系数(qP)、非光化学淬灭系数(qN)的综合权重值较高。【结论】新品种‘垂枝粉玉’耐热较强,‘上植月光曲’、‘上植欢乐颂’和‘玫玉’中等耐热,‘玫瑰春’、‘上植华章’和‘金叶粉玉’耐热性较弱;叶绿素、类胡萝卜素、叶黄素含量可作为山茶短期耐热性考察指标,而叶绿素a/b、F_(v)/F_(m)、qP、qN可作为山茶长期耐热性的考察指标。
[Objective]The heat tolerance of Camellia attracts more attention due to its rich flower types and colors and long flowering period.Suitable evaluation methods and indexes can provide bases for the heat-tolerance identification,the discovery of heat-tolerance germplasm,and the breeding of new cultivars of Camellia.[Methods]C.uraku and‘Wirlinga Cascade’were used as reference materials,and 7 new cultivars of cluster-flowering camellia were selected as test materials.They were cut in vase.After short-term(5 h)or long-term(7 d)high-temperature(42℃/35℃)treatment,changes of morphological and photosynthetic indexes were investigated and heat tolerance was evaluated comprehensively.[Results](1)The contents of chlorophyll,carotenoid,and chlorophyll a/b,net photosynthetic rate(Pn),and stomatal conductance(Gs)of‘Chuizhi Fenyu’and‘Wirlinga Cascade’were increased.Their maximum photo-chemical efficiency of PSⅡ(F_(v)/F_(m)),potential activity of PSⅡ(F_(v)/F_(o)),and electron transport rate(ETR)were remained at a high level.Additionally,they did not show signs of heat damage after 7 days of high temperatures.Pn and Gs of‘Jinye Fenyu’,‘Shangzhi Huazhang’,and‘Meigui Chun’were de-creased significantly under high temperature stress,while intercellular CO2 concentration(Ci)was in-creased.Among them,the F_(v)/F_(m),F_(v)/F_(o),and ETR of‘Jinye Fenyu’and‘Shangzhi Huazhang’were significantly reduced.After 7 days of long-term high temperature stress,these 3 cultivars showed severe heat damage or became dead.(2)15 individual indicators were converted into 4 independent comprehensive indicators with cumulative contribution rate of 90%through principal component analysis.The compre-hensive weight values of chlorophyll content,carotenoid content,and xanthophyll content were higher at 5 h under high temperature stress,and the comprehensive weight values of chlorophyll a/b,F_(v)/F_(m),photo-chemical quenching coefficient(qP),and non-photochemical quenching coefficient(qN)were higher at 7 d under high temperature stress.[Conclusion]According to the comprehensive evaluation value D,‘Chuizhi Fenyu’is a heat-tolerance cultivar,‘Shangzhi Yueguangqu’,‘Shangzhi Huanlesong’,and‘Sweet Gem’are moderate tolerance,and‘Meigui Chun’,‘Shangzhi Huazhang’,and‘Jinye Fenyu’are the weakest among the new cultivars of cluster-flowering camellia.Chlorophyll,carotenoid,and xanthophyll contents can be used as the key indicators to analyze the short-term high temperature stress,while chlorophyll a/b,F_(v)/F_(m),qP,and qN can be used as the key indicators to analyze the long-term high temperature stress of Camellia.
作者
郭卫珍
宋垚
章丹峰
张春英
GUO Weizhen;SONG Yao;ZHANG Danfeng;ZHANG Chunying(Shanghai Research Center of Urban Plant Resources Development and Application&Engineering and Technology,Shanghai Botanical Garden,Shanghai 200231,China;Hangzhou Botanical Garden,Hangzhou 310000,China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2024年第4期539-550,共12页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金项目(31960327)
上海市绿化和市容管理局科技攻关项目(G210304)。
关键词
束花茶花
高温胁迫
光合色素
气体交换参数
叶绿素荧光参数
综合评价
cluster-flowering camellia
high temperature stress
photosynthetic pigments
gas exchange parameters
chlorophyll fluorescence parameters
comprehensive evaluation
作者简介
郭卫珍(1988—),女,硕士研究生,主要从事山茶新品种培育和适应性评价研究。E-mail:guowz@shbg.org;通信作者:张春英,教授,主要从事木本植物栽培及品种培育研究。E-mail:3392346181@qq.com。
