孕穗期低温对小麦生理抗寒性的影响

为了解孕穗期小麦的生理抗寒性,以参加黄淮海麦区区试的24个小麦品种(系)为材料,采用盆栽试验,在人工气候室内模拟孕穗期低温胁迫,测定和分析了低温处理后小麦叶片相对电导率、丙二醛(MDA)含量、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的变化。结果表明,孕穗期低温胁迫后,小麦叶片相对电导率、MDA含量、可溶性糖含量、SOD活性显著高于对照,POD活性显著低于对照,可溶性蛋白和游离脯氨酸含量的变化在品种(系)间存在差异。从7个性状的相对值来看,相对电导率最高,POD活性最低。通过隶属函数法和极点排序法计算得到的参试小麦平均隶属度值和综合排序值分别为0.17~0.64和1.93~4.02,二者与叶片可溶性糖含量、可溶性蛋白含量、SOD活性呈显著正相关,与相对电导率和MDA含量呈负相关。根据平均隶属度值和综合排序值,将参试小麦品种(系)抗寒性聚为5类,其中冀麦585和石B05-7388的孕穗期抗寒性最强,山农055843和C-44抗寒性最弱。

Effects of Low Temperature at Booting Stage on Physiological Cold Resistance of Wheat

In this study, 24 wheat varieties (lines) grown in the Huanghuaihai region were chosen as experimental materials. The wheat plants were grown in pots outdoors, and they were moved into an artificial climate chamber to receive a cold treatment at booting stage. Seven physiological indicies in leaves were measured after cold treatment to understand the physiological cold resistance of different wheat varieties. The results showed that the relative electrical conductivity, soluble sugar content, MDA content and SOD activity showed higher values in the low-temperature treated plants than those in the control plants (P<0.01), and POD activiey was lower than that of CK, while soluble protein and free proline content showed fluctuations among different vatieties. Among the 7 indicies, the relative value of relative electrical conductance was the highest, and the relative value of POD activity was the lowest. For each wheat variety, the relative character values were used to calculate the average subordinative function value by the subordinative function method, and the comprehensive score by the polar ordination method. The average subordinative function values ranged from 0.17 to 0.64 and the comprehensive scores ranged from 1.93 to 4.02. Correlation analyses showed that the average subordinative function value and comprehensive score were significantly and positively correlated with soluble sugars content, soluble protein content and SOD activity (P<0.05), meanwhile they were significantly and negatively correlated with MDA content and relative electrical conductivity (P<0.05). Using K-means clustering analysis, the 24 winter wheat cultivars were divided into five groups named as strong, high, medium, low, and weak according to their cold resistance. The strong cold resistance group contained Jimai 585 and Shi B05-7388, and Shannong 055843 and C-44 were in the weak cold resistance group.