不同小麦品种茎秆形态特征和解剖结构对多效唑的响应差异

为明确多效唑提高小麦抗倒伏能力的最佳喷施时期及不同小麦品种对多效唑响应的差异，以8个小麦品种为试验材料，分析不同叶龄期喷施多效唑对小麦茎秆抗倒伏能力、形态特征和解剖结构的影响以及不同抗倒性能小麦对多效唑响应的差异。结果表明，喷施多效唑可显著降低小麦株高、重心高度和节间长度，增加节间充实度、小维管束个数和机械组织厚度，提高小麦的抗倒伏指数，并且倒五叶期喷施效果最佳，其次为倒四叶期。在倒五叶期，与对照相比，多效唑对株高、重心高度和基部节间长度的降幅分别为2.58%~6.45%、3.52%~10.18%和6.64%~24.16%，对节间充实度、小维管束个数和机械组织厚度的增幅分别为22.41%~109.49%、10.00%~16.98%和12.76%~49.85%。不同抗倒性能小麦品种对多效唑的响应与喷施时期有关，在倒五叶处理下，多效唑对中等抗倒型小麦品种的抗倒效果比抗倒伏型和易倒伏型小麦品种明显；而在倒四叶和倒三叶处理下，多效唑对易倒伏型小麦品种的抗倒伏效果大。综合来看，倒五叶期喷施多效唑对小麦抗倒伏能力提升效果最佳，其次为倒四叶期；中等抗倒和易倒伏小麦品种喷施多效唑后小麦抗倒伏能力提升效果优于抗倒伏小麦品种。

Morphological and Anatomical Characteristics of Wheat Varieties and Its Response to Paclobutrazol

In order to determine the best paclobutrazol spraying period to raise the capacity of wheat lodging resistance and find the response difference of varieties to paclobutrazol,eight wheat varieties have been studied to analyze the effects of paclobutrazol on stem lodging resistance,morphological and anatomical characters,and the response difference of different lodging resistant wheat types to paclobutrazol was studied. The result showed that plant height,center of gravity height and length of internodes were reduced,while filling degree of internodes,small vascular bundle number and mechanical tissue layer thickness were increased under paclobutrazol treatment,leading to the increased lodging resistant indices. The effect of paclobutrazol spraying was biggest under reciprocal fifth leaf treatment,followed by that of reciprocal fourth leaf treatment. Under reciprocal fifth leaf treatment,comparing with control,the reduce rate of plant heights,center of gravity height and length of internodes were 2.58%-6.45%,3.52%-10.18% and 6.64%-24.16%,respectively,and the increase rate of filling degree of internodes,small vascular bundle number and mechanical tissue layer thickness were 22.41%-109.49%,10.00%-16.98% and 12.76%-49.85%,respectively. The influence of paclobutrazol on different lodging resistant wheat types associated with paclobutrazol spraying periods,and the lodging resistance increase effect was larger for lodging medium types,compared with lodging resistance types and lodging susceptible types in reciprocal fifth leaf treatment,but the lodging resistance increase effect was larger for lodging susceptible types,compared with lodging resistance types and lodging medium types in reciprocal fourth leaf and third leaf treatments. In conclusion,the best paclobutrazol spraying period to raise the capacity of wheat lodging resistance is reciprocal fifth leaf period,followed by reciprocal fourth leaf treatment. The response of lodging medium types and lodging susceptible types to paclobutrazol were better,compared to that of lodging resistant wheat varieties.