低温冻害对大白菜形态变化的影响

Influence of Low Temperature Freezing Injury on Chinese Cabbage Morphological Changes

秋冬大白菜生产是解决贵州冬春叶菜淡季供应的关键,受冬季低温雨雪天气的影响,冻害制约着秋冬种反季节大白菜的品质和产量。研究贵州秋冬种大白菜低温冻害指标,可为大白菜低温冻害的灾害预警、种植区划和反季节栽培提供理论依据和实践指导。本试验研究以贵州省普遍种植的大白菜品种"鲁白六号"为试验材料,在莲座期将其置于人工气候室,设置5个不同的恒定低温,根据自然条件下低温天气过程气温日变化规律设定4个动态低温变化,分别进行低温胁迫处理,探讨冻害与低温强度及其持续时间的关系,从而确定大白菜低温冻害指标。试验研究结果表明:贵州秋冬种反季节大白菜莲座期长时间低温冻害临界温度是-4℃,持续时间为10 h。动态低温轻度冻害指标是日最低气温-2~0℃,持续时间2 d以上;动态低温中度冻害指标是日最低气温-4^-2℃,持续时间1-2 d;动态低温重度冻害指标是日最低气温-4^-2℃,持续时间2-3 d;动态低温极重冻害指标是日最低气温-6^-4℃,持续时间2 d以上。

The production of autumn and winter cabbage is the key to solve the supply of vegetables in slack season in Guizhou province, influenced by low temperature, snow and rain, freezing injury restricts the quality and production quantity of Chinese cabbage which planted in anti-season. Studying the index of low temperature cold injury of Chinese cabbage in Guizhou province, could provide theoretical basis and practical guidance for the disaster warning of low temperature and freezing injury of Chinese cabbage, planting regionalization and anti-season cultivation. The Chinese cabbage of ＂Lu Bai VI＂ was used as the experimental material which was universally planted in Guizhou province, in the study, we placed it in the artificial climate chamber at the rosette stage, set up five different constant low temperatures, and four dynamic changes in low temperature according to the diurnal change of temperature in low temperature process under the natural conditions, conducted the low temperature stress respectively, through investigated the relationship between the freezing injury and the strength and duration of low tem- perature, identified the low temperature cold injury index of Chinese cabbage. The results show that ： the low temperature freezing injury critical temperature is -4 ℃ during the rosette stage, duration of 10 h of Chinese cabbage in Guizhou province, the lowest day temperature is - 2--0 ℃ of the dynamic mild cold injury index in the low temperature, duration more than 2 d, the lowest day temperature is -4---2 ℃ of the dynamic medium cold injury index in the low temperature, duration 1--2 d, the lowest day temper- ature is - 4-- - 2 ℃ of the dynamic severe cold injury index in the low temperature, duration 2--3 d, the lowest day temperature is -6-- -4 ℃ of the dynamic extremely low temperature injury index in the low temperature, duration more than 2 d.