越冬前北方不同类型强冬性冬油菜形态及生理响应研究

Comparison of morphological and physiological responses of two different species of northern winter rapeseed before overwintering

为了研究比较越冬前北方两种不同类型冬油菜的生长特性,于2020年10—11月选用强冬性白菜型冬油菜和强冬性甘蓝型冬油菜品种,分析其越冬前降温过程中的形态特征、光合特性和渗透调节物质含量变化,并与越冬率进行了相关性分析。结果表明,越冬前随着温度的降低,白菜型冬油菜根冠比增加164.7%,甘蓝型冬油菜根冠比变化不大,两个品种间差异显著,但二者组织含水量变化为69%~89%,变化幅度较小。随着温度的降低,白菜型冬油菜和甘蓝型冬油菜的叶面积逐渐减小,下降幅度为5%~16%,叶绿素SPAD值整体呈现增加的趋势;光合速率、蒸腾速率、气孔导度均逐渐下降,降幅为54%~64%,胞间CO_(2)浓度逐渐上升19%~29%。叶片和根部的可溶性蛋白、脯氨酸含量均增大,增幅为26%~91%;叶片可溶性糖含量先增加后降低,根部可溶性糖含量先降低后增加。叶片的钠离子和钾离子含量逐渐降低了20%~47%,钙离子含量先增加后降低;根部钾离子和钙离子含量先下降后上升;白菜型冬油菜根部钠离子含量呈现出逐渐上升的趋势,甘蓝型冬油菜呈现出先上升后下降的趋势。由此推断白菜型冬油菜陇油6号的抗寒性强于甘蓝型冬油菜2019-QL-GAU-30。

Two strong winter rapeseed Brassica rapa L.and Brassica napus varieties were selected from October to November 2020 to study and compare the growth characteristics of two different types of winter rape in northern China before overwintering.Changes in morphological characteristics,photosynthetic characteristics and osmotic regulation characteristics,and correlation analysis with overwintering rate were observed.The results showed that with the decrease of temperature before overwintering,the root-shoot ratio of winter rapeseed Brassica rapa L.increased by 164.7%,while the root-shoot ratio of winter rapeseed Brassica napus did not change much,and there was a significant difference between the two varieties.The tissue water content of both varieties changed slightly,ranging between 69%and 89%.With the decrease of temperature,the leaf area of winter rapeseed Brassica rapa L.and winter rapeseed Brassica napus gradually decreased by 5%~16%,and the SPAD value of chlorophyll showed an overall increasing trend.The photosynthetic rate,transpiration rate,and stomatal conductance were all gradually decreased by 54%~64%,and the intercellular CO_(2)concentration gradually increased by 19%~29%.The contents of soluble protein and proline in leaves and roots increased by 26%~91%.The content of soluble sugar in leaves first increased and then decreased,and the content of soluble sugar in roots decreased first and then increased.The content of sodium ion and potassium ion in leaves gradually decreased by 20%~47%,and the content of calcium ion increased first and then decreased.The content of potassium ion and calcium ion in the root first decreased and then increased.Brassica napus showed a trend of rising first and then falling.Findings suggest that the cold resistance of winter rapeseed Brassica rapa L.Longyou 6 is stronger than that of winter rapeseed Brassica napus 2019-QL-GAU-30.