This study was aimed to explore the physiological response mechanism of alfalfa(Medicago sativa)seedlings under low temperature stress by screening cold-resistant alfalfa germplasm materials suitable for planting in western Heilongjiang,so as to provide theoretical basis for identification of cold-resistant alfalfa germplasm resources.Four alfalfa varieties were treated at low temperature.Physiological indexes proline(Pro),soluble sugar(SS),malondialdehyde(MDA),superoxide dismutase(SOD),peroxidase(POD),relative electrical conductivity and the expresion level of genes(NAC3、CAS18)were measured.The cold-resistant alfalfa varieties were screened by membership function evaluation.Results showed that with the aggravation of low temperature stress,the Pro,SS,MDA and relative electrical conductivity of tested alfalfa varieties increased,while SOD and POD activity increased first and then decreased.Under severe stress,the Pro,SS,SOD and POD of Zhaodong alfalfa were the highest,while the electrical conductivity was the lowest;Meanwhile,the gene expressions of NA C3 and CA S1 8 of Zhaodong alfalfa were significantly higher than those of other varieties(P＜0.05).Membership function was used to evaluate the cold resistance of alfalfa varieties.The cold resistance of alfalfa varieties from high to low was as follows:Zhaodong＞Queen＞420＞Sardi.
关键词
紫花苜蓿/幼苗期/低温/生理特性/抗寒基因/评价
Key words
Medic ago sativa/seedling stage/low temperature/physiological characters/cold resistance genes/evaluation
维普
万方数据