小麦野生近缘物种是小麦品种改良的重要基因库,可为小麦抗寒力的提高提供丰富的基因资源。以抗寒性较好的三芒山羊草、冰草和强冬性小麦品种M808为试材,以春小麦材料中国春为对照.研究了低温处理对小麦族物种抗寒生理指标的影响。结果表明:低温胁迫下,所有材料相对电导率均呈现上升趋势,中国春上升最快,96h后达到90%,M808次之,而三芒山羊草和冰草相对较慢;可溶性蛋白含量在24h内变化不显著,随着低温胁迫时间的延长,三芒山羊草和冰草上升趋势较为明显,72h时达到峰值并开始下降;脯氨酸含量较未胁迫时有很大幅度的提高,96h后达到25~30μgFW·g^-1的范围,三芒山羊草和冰草提高程度明显高于小麦材料;在相同的处理时间下,三芒山羊草和冰草的SOD活性也高于小麦材料;低温胁迫初期所有材料MDA含量迅速增加,24h后平缓上升,72h达到峰值,约90nmol·g^-1,随后呈现下降趋势;可溶性糖含量低温胁迫初期有下降趋势,24h以后有所提高。综合分析发现三芒山羊草、冰草和冬小麦米808相应指标变化明显比春小麦更倾向于提高抗寒水平的方向发展,而三芒山羊草和冰草的抗寒生理基础要强于冬小麦品种M808。这些将为小麦族抗寒材料的发掘和抗寒生理机制的明确提供重要参考.
The wild relatives of wheat are an important genetic resource for breed improvement of wheat, providing abundant gene resources to improve the cold hardiness of wheat. In this study, Aegilops neglecta, Agropyron, winterness wheat (Triticum aestivum L., M808) that have good cold hardiness were placed at different hours of low temperature treatment, and then determined the physiological indices of the Triticeae species, spring wheat (Chinese Spring) was used as control. The results of physiological indices suggested that the relative electronic conductivity showed a rising trend as low temperature hours increased, and that of wheat increased faster than that of Aegilops neglecta and Agropyron. The protein content in wheat seedlings declined slightly within the initial 24 hours. The protein content of Aegilops neglecta and Agropyron were significantly higher. After 72 chilling hours, the protein content dropped. The contents of free proline increased quickly as the stress hours increased, the proline content of Aegilops neglecta and Agropyron increased faster than that of wheat. The temperature on the same te~ns, the activity of superoxide dismutase (SOD) of Aegilops neglecta and Agropyron changed greater than that of wheat. The content of MDA significantly increased in initial time, and then tended to be stable. After 72 chilling hours, the MDA contents dropped. Soluble sugar contents showed a steep drop firstly under low temperature stress, and then increased subsequently. The results of comprehensive analysis according to the variety of physiological indices showed that Aegilops neglecta and Agropyron were not far from cold resistance, but they were higher than winter wheat M808 and spring wheat CS. These could offer precious information for abundance of the novel material and better understanding for physiological mechanism of cold hardiness in Triticeae.