不同穗分化时期冬小麦形态抗冻性评价

通过对黄淮麦区冬小麦5个穗分化时期低温胁迫下的株高进行分析，发现随时期推后株高对低温胁迫的响应越来越强，除-1℃外，随胁迫温度的降低，响应越来越强。对株高关键组成部分穗长、穗下节长、倒二节长和基部节长利用隶属函数法结合主成分分析，来确定冬小麦株高是否对晚霜冻害响应、响应的程度及隶属函数法是否适用于形态抗冻性评价，分别将穗长、穗下节长、倒二节长和基部节长四个具有相关关系的指标降维成2个独立的综合指标，根据这两个综合指标的贡献率求出相应的隶属函数值，并根据各综合指标的权重和隶属函数值得出抗冻性的综合评价值（D值）。结果表明拔节期5个穗分化时期的株高抗冻性中护颖原基分化期的株高抗冻性最低，小花原基分化期、雌雄蕊原基分化期、药隔形成期和四分体时期比护颖原基分化期的抗冻性要高，且时期越往后，D值越高，说明时期越往后，株高的抗冻性越高。5个时期的D值都在0.3~0.6之间，说明本实验所用冬小麦5个穗分化时期都为中等抗冻。同时也说明隶属函数法同样可以运用于冬小麦形态抗冻性评价。

Frost Resistance Evaluation Based on Winter Wheat Form in Different Spike Differentiation Stage

By analyzing the plant height of 5 winter wheat varieties in spike differentiation period at Huanghuaihai areas, it was found that along with time postpone, plant height had stronger and stronger response to low temperature stress except -1℃. In this paper, membership function method and principal component analysis were used to evaluate the frost-resistance of winter wheat, and to determine whether the winter wheat plant height responding to frost damage, the degree of response and whether membership function method suitable for evaluating morphological frost resistance. Two independent and comprehensive indexes were integrated by 4 indicators, including spike length, spike section length, length of top 2nd sections, and length of base section. According to the contribution of these 2 comprehensive indexes, the corresponding membership function value was found. And according to the weight of each composite indicator and subordinative function value, comprehensive index for frost resistance (D value) was obtained. Results indicated that the frost resistance of plant height in sterile lemma primitive differentiation phase was lower than the other 4 stages. As time went on, the D value became higher and higher, indicating that frost resistance of plant height was higher at the later stage. The D values during the 5 periods were between 0.3 and 0.6, indicating that the 5 panicles of winter wheat used in this experiment were of medium frost resistance. It also proved that the membership function method could be applied to evaluate winter wheat morphological frost resistance.