5个油橄榄品种抗寒能力综合评价

A comprehensive evaluation of the cold resistance ability of 5 olive cultivars

为了解油橄榄幼苗对低温胁迫的生理响应机制,探究油橄榄不同品种苗期的抗寒性,以甘肃陇南油橄榄适生区表现优良的油橄榄5个栽培品种(豆果、鄂植8号、佛奥、莱星、柯基)2年生扦插苗为试材,人工模拟低温胁迫,测定其光合指标、抗氧化酶、渗透调节物质、相对电导率和丙二醛含量.结果表明,低温胁迫显著影响5个供试油橄榄品种幼苗的光合作用,其净光合速率、气孔导度、胞间CO_(2)浓度和蒸腾速率均下降;低温胁迫下,5个供试油橄榄品种幼苗叶片超氧化物歧化酶、过氧化物酶、过氧化氢酶活性较对照组呈上升趋势;可溶性糖和脯氨酸含量较对照组呈增加趋势;随胁迫温度降低,各品种叶片相对电导率呈上升趋势,丙二醛含量呈先降后升的趋势;结合主成分分析和隶属函数法综合得出5个供试油橄榄品种幼苗的抗寒性排序为莱星>佛奥>豆果>柯基>鄂植8号.低温胁迫影响油橄榄幼苗的光合特性,使其光合速率下降.胞间CO_(2)浓度、超氧化物歧化酶、过氧化氢酶、可溶性糖、相对电导率和丙二醛在油橄榄幼苗耐寒过程中发挥主要作用.莱星和佛奥的抗寒性较强,可作为冷凉地区示范推广的耐寒参考品种.

The purpose of this study was to understand the physiological and ecological response mechanism of olive seedlings to low temperature stress,explore the cold resistance of different varieties of olive and provide a theoretical reference for the selection of low temperature-resistant varieties,so as to expand the area of olive suitable area in higher elevations of a dry-heat river valley.Taking two-year-old cuttings of olive(Arbequina,EZ-8,Frantoio,Leccino,Koroneiki)with excellent performance in Longnan,Gansu Province,we simulated low temperature stress and measured the photosynthetic characteristics,antioxidant enzymes,permeation substances and cell membrane permeability.It was found that low temperature stress significantly affected the photosynthesis of five seedlings of tested olive cultivars,reducing the net photosynthetic rate,stomatal conductivity,intercellular CO_(2)concentration and transpiration rate;under low temperature stress,the activity of leaf superoxide dismutase,peroxidase,catalase of 5 olive seedlings increased compared with CK;the content of soluble sugar and proline increased compared with CK;with the decrease of the stress temperature,the relative conductivity of the blade of each variety showed an increasing trend,and the content of maldialaldehyde decreased first and then rose;a principal component analysis combined with the membership function method confirmed the order of the cold resistance of five seedlings of tested olive cultivars as Leccino>Frantoio>Arbequina>Koroneiki>EZ-8.Low-temperature stress affected the photosynthetic properties of olive seedlings and decreased their photosynthetic rate.Intercellular CO_(2)concentration,superoxide dismutase,catalase,soluble sugar,relative conductivity and malondialdehyde played major roles in cold tolerance in olive seedlings.Leccino and Frantoio had a strong cold resistance,which can be used as reference cultivars for demonstration and promotion in cold regions.