药隔期低温胁迫对小麦生理及产量的影响

为揭示小麦春季耐寒性的生理生化机制,以不同春季耐寒性的8个小麦品种为材料,采用田间盆栽和药隔期低温胁迫的方法,探讨了药隔期低温胁迫后小麦的生理及产量变化.结果表明,药隔期低温胁迫后,小麦单株产量明显下降,平均降幅为68.4％,其中淮麦20、皖麦38、西农979和矮丰3号表现出较好的春季耐寒性,单株产量降幅均小于65％,而陕麦139、郑366、小偃22和郑麦9023单株产量降幅较大(＞70％),耐寒性相对较差；小麦叶片丙二醛含量、SOD活性、POD活性、脯氨酸含量和可溶性蛋白含量均不同程度升高,其中淮麦20、皖麦38、西农979和矮丰3号丙二醛含量的增幅明显小于平均增幅,SOD活性、POD活性、脯氨酸含量和可溶性蛋白含量的增幅显著大于平均增幅,表现出较低的细胞膜受损程度和较强的耐寒性.在生理指标中,SOD活性、POD活性、脯氨酸含量和可溶性蛋白含量与产量的关联度高,因此可作为春季低温下小麦耐寒性鉴定的重要指标.

Effects of Low Temperature Stress at Anther Connective Formation Phase on Physiological Characteristics and Yield of Wheat

Spring frost impacts young ear's growing and results in a diminished yield in wheat (Triticum aestivum L.). Many studies indicate that anther connective formation phase is the low temperature sensitive phase in spring. Although a few investigations have studies the physiological mechanism of low temperature stress in wheat,the physiological characteristics,the relationships between these physiological indices and grain yield were not completely clear. To dissect the change of physiological indices,correlation and their grey relational grade with yield in wheat after low temperature stress at anther connective phase,this study choose 8 wheat varieties with different resistance to spring frost for experiment,all of them were cultivated with pots in field and low temperature treatment at anther connective phase. The results showed that after low temperature stress at anther connective phase,yield per plant decreased significantly with an average of 68.4%. Huaimai20,Wanmai38,Xinong979 and Aifeng 3 had a small drop (<65%) ,Shanmai139,Zheng366,Xiaoyan22 and Zhengmai9023 had a larger drop (>70%). Huaimai20,Wanmai38,Xinong979 and Aifeng 3 showed resistance in a better performance. Meanwhile,the content of malondialdehyde (MDA),proline and soluble protein,the activities of superoxide dismutase (SOD) and peroxidase (POD) in leaf increased differently after low temperature stress at anther connective phase. Huaimai20,Wanmai38,Xinong979 and Aifeng 3 had a smaller increase of MDA content than the average,and a larger increase in activities of SOD,POD and contents of proline,soluble protein than the average. Their cytomembranes showed a low degree of damage and a strong cold resistance. Under the low temperature stress,significant and negative correlations were observed in MDA content with other physiological indices,and the correlation coefficients ranged from -0.749 (P<0.05) to -0.883 (P<0.01); SOD,the POD activity and the contents of proline,soluble protein showed a significant and positive correlations with each other,the correlation coefficients ranged from 0.798 (P<0.05) to 0.963 (P<0.01). The gray relational grade analysis indicated that the contents of soluble protein,proline and the activities of SOD,POD had a higher relational grade,and connected closely with the grain yield per plant. Therefore,they were considered as important indices in the selection of spring frost tolerance in wheat.