11个北高丛越橘品种对干旱胁迫的响应

【目的】揭示北高丛越橘对干旱胁迫的响应机制并筛选出耐旱性较强的越橘品种。【方法】以11个北高丛越橘品种1年生扦插苗为试材,分别为‘蓝丰’‘瑞卡’‘双迪’‘斯巴坦’‘卡拉’‘伊丽莎白’‘钱德勒’‘布里吉塔’‘公爵’‘甜心’‘埃利奥特’,研究干旱胁迫对光合生理特性的影响,并评价不同品种的抗旱性。【结果】干旱胁迫20 d后,北高丛越橘品种脯氨酸含量、丙二醛含量、过氧化氢酶活性、胞间CO_2浓度均显著升高,而净光合速率、蒸腾速率、气孔导度、光系统Ⅱ实际光量子产量和电子传递速率均显著降低。通过主成分分析,将16项生理生化指标转化为3个互相独立的综合指标,累计贡献率达85.74%。主成分1主要反映叶片生理特性、抗氧化酶活性及主要的叶片荧光参数等信息,主成分2主要反映叶片气孔功能信息,主成分3主要反映叶片光合作用相关信息。通过聚类分析,将11个北高丛越橘品种划分为3个类型:‘甜心’‘公爵’和‘蓝丰’为抗旱型,‘布里吉塔’‘伊丽莎白’‘瑞卡’和‘埃利奥特’为中间型,‘钱德勒’‘双迪’‘斯巴坦’和‘卡拉’为不抗旱型。根据抗旱性综合评价值,11个北高丛越橘品种按照抗旱性由高到低排序依次为‘甜心’‘公爵’‘蓝丰’‘布里吉塔’‘伊丽莎白’‘瑞卡’‘埃利奥特’‘卡拉’‘斯巴坦’‘双迪’‘钱德勒’。【结论】采用主成分分析、隶属函数法、聚类分析等相结合的方法对北高丛越橘苗期耐干旱胁迫能力进行评估,可以较好地揭示性状指标与耐干旱胁迫能力的关系。11个北高丛蓝莓品种中‘甜心’‘公爵’和‘蓝丰’耐干旱胁迫能力较强。

Response of eleven northern highbush blueberry cultivars to drought stress

【Objective】In order to reveal response mechanism of northern highbush blueberry to drought stress,and to screen varieties with strong drought resistance.【Method】One-year-old cuttage seedlings of eleven northern highbush blueberry cultivars were used as test materials,including‘Bluecrop’‘Reka’‘D-ⅡMSU54’‘Spartan’‘Cara’s Choice’‘Elizabeth’‘Chandler’‘Brigitta’‘Duke’‘Sweetheart’and‘Elliott’,effects of drought stress on photosynthetic and physiological characteristics were studied,and drought resistances of different cultivars were evaluated.【Result】Proline content,malonaldehyde content,catalase activity and intercellular CO2 concentration are significantly increased under drought stress for twenty days.In contrast,net photosynthetic rate,transpiration rate,stomatal conductance,actual light quantum yield of PSⅡand electron transport rate are significantly decreased.Sixteen physiological and biochemical indexes are converted into three independent comprehensive indexes with 85.74%of accumulative contribution by using principal component analysis.The first principal component mainly reflects some information of leaf physiological characteristics,antioxidant enzyme activity and main leaf fluorescence parameters.The second principal component mainly reflect some information of stomatal function.The third principal component mainly reflect some information of leaf photosynthesis.Eleven northern highbush blueberry cultivars are divided into three types by using clustering analysis.Drought-resistance type includes‘Sweetheart’‘Duke’and‘Bluecrop’,intermediate type includes‘Brigitta’‘Elizabeth’‘Reka’and‘Elliott’,and drought-intolerant type includes‘Chandler’‘D-ⅡMSU54’‘Spartan’and‘Cara’s Choice’.The results of comprehensive evaluation of drought resistance show that,based on drought resistance ability from strong to weak,order of the eleven highbush blueberry cultivars is‘Sweetheart’‘Duke’‘Bluecrop’‘Brigitta’‘Elizabeth’‘Reka’‘Elliott’‘Cara’s Choice’‘Spartan’‘D-ⅡMSU54’‘Chandler’.【Conclusion】Drought resistance abilities of northern highbush blueberry seedlings can be evalued by using combination method of principal component analysis,membership function method and cluster analysis,and it can reflect relationship between characteristic indexes and drought resistance ability.Among the eleven tested cultivars,drought resistance abilities of‘Sweetheart’‘Duke’and‘Bluecrop’are stronger.