北方旱寒区冬油菜根系抗寒指标分析

为了研究北方旱寒区冬油菜根部生理特性与其抗寒性的相关性，对6个不同抗寒性冬油菜品种整个生育期根部的干物质积累、含水量、可溶性蛋白含量及相关保护性酶活性的变化进行了分析，并将各指标与越冬率进行了相关性分析，用与越冬率相关性显著、极显著的6个指标对冬油菜进行聚类分析。结果表明，降温前，各指标与越冬率的相关性均不显著；降温后，越冬率与可溶性蛋白含量、SOD活性极显著正相关，与POD、APX活性显著正相关，与根直径、根冠比、CAT活性正相关，与根含水量负相关；根据聚类分析结果，可将试验材料分为3类，第1类：07－G01，天油2号，天油4号，此类抗寒性弱，为耐寒性品种；第2类：上党，74－1，此类抗寒性一般，为中抗寒性品种；第3类：陇油6号，此类抗寒性强，为强抗寒性品种。由此推断，在北方旱寒区，冬油菜越冬前根直径大、根冠比高、根含水量低有利于冬油菜安全越冬；降温后，冬油菜可溶性蛋白、SOD、POD 、CAT和APX酶活性值越高，其抗寒性越强。

Analysis of cold-tolerant characters of winter rape roots in northern arid-cold area

To study the relationship between the cold tolerance and the physiological characters of winter rape root, an experiment was conducted to analyze the changes of the dry matter, the water content, the soluble protein and the enzymatic activity of the roots of six different cold-tolerant cultivars. It also analyzed the correlation between the winter survival rate and other indexes, and used six significant indexes to get the cluster analysis of the materials. The results showed that, before cooling, the correlation was not significant between winter survival rate and other indexes; but after cooling, the survival rate was most significantly positively correlated with soluble protein and SOD, significantly positively correlated with POD and APX, positively correlated with diameter of roots, root-shoot ratio and CAT activity, while negatively correlated with water content. According to the cluster analysis results, the test materials can be divided into three categories, 1: 07-G01, Tianyou 2 and Tianyou 4, weak cold-tolerant varieties; 2: Shangdang and 74-1, general cold-tolerant varieties; 3: Longyou 6, strong cold-tolerant varieties. So it can be deduced that the bigger the diameter and root-shoot ratio, the higher the winter survival rate; and the higher the SOD, POD, CAT and APX enzymatic activity, the stronger the cold tolerance of the winter rape.