Abstract:

【Objective】To clarify the cold resistance of 3 fresh jujube varieties with great development potential and provide a basis for the regional cultivation layout of Xinjiang fresh jujube varieties. 【Methods】In January, 2020, the annual shoots of Fucuimi, Jingcang 1 and Dongzao were collected, and the shoots were processed in an ultra-low temperature refrigerator to artificially simulate a low temperature environment (-10—-35℃) to determine the germination rate, the relative conductivity, osmotic adjustment substance, and malondialdehyde content. The semi-lethal temperature (LT₅₀) of the three varieties were obtained from their respective relative conductivity and Logistic equation, and then combined with the principal component analysis and the membership function to comprehensively evaluate the cold resistance of the three fresh jujube varieties. 【Results】With the decrease of the treatment temperature, the germination rate of the branches of the three jujube varieties decreased to varying degrees, but all fell to 0 at -25℃; the relative conductivity value, soluble sugar content, and malondialdehyde content basically increased the soluble protein content and the free proline content showed a trend of "rising-falling-rising"; the semi-lethal temperature of Fucuimi, Jingcang 1 and Dongzao were -20.44, -19.91, -19.53℃, respectively. Principal component analysis showed that two principal components could represent 71.189% of the information of each index of the three varieties. Principal component 1 mainly contained information on soluble sugar, germination rate, malondialdehyde, soluble protein, and relative conductivity. Principal component 2 contained information on amino acids. The scores of principal component analysis and membership function of Fucuimi were the highest, followed by Dongzao, and the lowest in Jingcang 1.【Conclusion】The cold resistance of the branches of the three varieties were Fuqiuanmi, Dongzao and Jingcang 1. Therefore, in the areas where winter jujube is planted in southern Xinjiang, Fubrittle honey with strong cold resistance is suggested to be promoted, while Jingcang 1 is relatively weak in cold resistance, so timely anti-freezing protection measures should be taken in winter.

Key words: cold resistance; LT₅₀; principal component analysis; membership function

摘要：

【目的】研究3个鲜食枣品种的抗寒能力,为新疆鲜食枣品种的区域栽培布局提供依据。【方法】2020年1月,采集伏脆蜜、京沧1号、冬枣的一年生枝条,利用超低温冰箱人工模拟低温环境(-10℃~-35℃)处理枝条,测定萌芽率、相对电导率、渗透调节物质、丙二醛含量,3个品种半致死温度(LT₅₀)由各自的相对电导率配合Logistic方程得到,再结合主成分分析和隶属函数,综合评价3个鲜食枣品种的抗寒性。【结果】随着处理温度的下降,3个枣品种枝条的萌芽率呈现不同程度的下降,但均在-25℃降至0;相对电导率值、可溶性糖含量、丙二醛含量基本呈现上升趋势,但上升幅度不同;可溶性蛋白含量、游离脯氨酸含量则呈现“上升—下降—上升”的趋势;伏脆蜜、京沧1号、冬枣的半致死温度从高到低分别为-20.44、-19.91和-19.53℃。2个主成分能表示三个品种各个指标71.189%的信息,主成分1主要包含可溶性糖、萌芽率、丙二醛、可溶性蛋白、相对电导率的信息,主成分2包含脯氨酸的信息。而主成分分析与隶属函数的得分均为伏脆蜜最高,其次是冬枣,京沧1号最低。【结论】3个品种枝条的抗寒能力强弱依次为伏脆蜜、冬枣、京沧1号。在新疆南疆种植冬枣的区域,可选择抗寒能力强的伏脆蜜,而京沧1号抗寒性相对较弱,需在冬季及时做好防冻保护措施。

关键词: 抗寒性, LT₅₀, 主成分分析, 隶属函数