冬小麦品种抗霜力鉴定与霜冻害防御新对策

冬小麦发育进入拔节期和出现霜冻低温是形成其霜冻害的两个要素。霜冻低温的出现主要与气候因素有关。而拔节期的早晚则受初春气温、播种期和选用品种等多种因素的影响。影响品种抗霜力的重要因素是幼穗分化时期。品种抗霜力的鉴定必须在相同的幼穗分化期,建议在药隔期进行。品种的抗霜力还与第1茎节的长度有关,而与抗冻力和叶片可溶性糖含量的相关性不显著。通过研究,提出了下列抗霜对策:在把握地区霜冻温度出现规律的基础上,合理规划抗霜品种与避霜品种的布局;通过常规育种和基因工程手段,改良品种的抗霜力;通过遗传操作磷脂酶D基因,改良冬小麦的抗霜性。

Evaluation of frost resistance of winter wheat varieties and some new countermeasures against frost damage

Developing into jointing stage and occurrence of frost temperature are two main factors for frost damage of winter wheat.The occurrence of frost temperature is mainly impacted by local climate condition,while the time of jointing stage is determined by many factors as mean air temperature in early spring,sowing time,and the varieties selected etc.Differentiation stage of young ears is an important factor that affects frost resistance of winter wheat. Therefore,evaluation of frost resistance of different varieties is suggested to be performed at a same stage in order to get reliable result.Among those stages,anther connective stage is recommended as an appropriate evaluation stage. Frost resistance of winter wheat varieties correlates with the length of the first internode,and no significant correla- tion are found between freezing resistance and content of soluble sugar of leaves.Following strategies for preventing frost damage to winter wheat are proposed:planning the planting pattern for frost resistant and frost avoiding varie- ties feasibly according to the occurrence of frost temperature in local area,improving frost resistance of the varieties through breeding and genetic engineering and enhancing frost resistance of winter wheat through genetic manipula- tion of phospholipase D.