甘蓝型冬油菜在西北不同生态区适应性及生理生化反应

选用50个国内外甘蓝型冬油菜品种,在兰州和天水两个生态区进行大田种植,苗期进行田间植物学形态特征统计,越冬前降温期对叶片过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)、可溶性蛋白(SP)含量以及相应光合参数进行测定,研究它们在不同生态区的抗寒适应性和生理生化反应。结果显示:由天水北移至兰州后,各参试品种越冬率大幅下降,证明天水是我国冬油菜分布北界;部分品种形态特征发生变化,78%的叶色加深,52%的叶柄变短,大多数品种的侧裂叶对数由1~2对增至3~4对;胞间CO2浓度(Ci)和气孔导度(Gs)下降,平均降幅为1.54%和60.53%,蒸腾速率(Tr)显著升高,平均升幅为44.27%,不同品种的光合速率(Pn)变化存在较大差异;同时,CAT、POD、SOD酶活性、MDA和可溶性蛋白含量都有所升高,其中POD酶活性和MDA含量升高幅度较大,分别为82.59%和48.82%。相关性分析表明,两地的越冬率与POD酶活性和可溶性蛋白含量呈极显著正相关,而与MDA含量呈极显著负相关。

Adaptation and physiological and biochemical characteristics of winter rapeseed (Brassica napus L.) in different eco-regions of northwest China

In this research, filed experiments in Tianshui (original planting area) and Lanzhou (extending northern area), Gansu province, with 50 winter varieties of B.napus rapes from domestic and international resources, were conducted to study the adaptation and the physiological and biochemical characteristics of the winter Brassica napus. The following indexes were included in this analysis including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) activities, malondialdehyde (MDA), soluble protein (SP) contents, and photosynthetic parameters during the pre-winter cold acclimation stage. The results showed that the wintering rate of varieties (lines) tested in Lanzhou was decreased largely compared to that in Tianshui, which suggested that Tianshui was the north boundary of winter rape planting. Some growth morphologies of winter rapeseed seedlings were changed. 78% of leaf color of varieties (lines) were deepened, 52% of the petiole length of varieties (lines) became shorter, and the number of cleft leaf pairs of most varieties (lines) went increased from 1-2 to 3-4. Gs and Ci of leaves were decreased by 1.54% and 60.53% on average, respectively, while Tr was increased by 44.27% with low temperature treatment. Pns of different varieties (lines) varied significantly. The protective enzyme activities, soluble protein and MDA contents of the varieties tested in Lanzhou were increased compared to those in Tianshui, and the average increases were 29.37% and 48.82%, respectively. Through correlation analyses, it was found that there were significant positive pairwise correlations among the POD activity, soluble protein content and the wintering rate, and a negative correlation between MDA content and the wintering rate.