超级稻Y两优2号在两生态区的抗倒性分析

摘要

2011-2012年在水稻特高产生态区(云南涛源)和太湖稻区(江苏丹阳),以超级稻品种Y两优2号为材料,通过比较倒伏指标、形态、生理特征指标,分析不同生态区抗倒性差异及氮素对水稻抗倒性影响.结果表明,特高产生态区水稻倒伏指数显著低于太湖稻区.主要原因是其株高及重心高度较低,植株的弯曲力矩较小,基部茎秆弯曲应力、叶鞘单位长度干重弥补了其粗度及壁厚在抗折能力上的劣势.两生态区倒伏指数与弯曲应力、抗折力呈显著负相关.特高产生态区受氮素影响显著,随氮素用量增加,株高、穗颈高、重心高度、上三叶长度及干重显著增加,基部茎秆强度、充实度显著降低,抗折能力下降；太湖稻区增加氮素用量时,株高、上三叶干重显著增加,抗折力显著降低.氮素后移使茎秆机械强度降低,但有利于增加茎秆粗度及壁厚.%Experiments were conducted with super-hybrid rice Y Liangyou 2 at Taoyuan,Yunnan Province and Danyang,Jiangsu Province in 2011 and 2012.The main objective of this study was to reveal the difference of lodging resistance and effects of nitrogen on rice lodging resistance between two ecological regions.Rice lodging indexes were 15％ lower at Taoyuan than at Danyang.Bending moment of whole plant was 74.2％ at Taoyuan lower than that at Danyang.Bending stress and dry matter weight of leaf sheath at basal stem made up the deficiency in stem diameter and wall thickness.There exited significantly negative correlations between lodging indexes and bending stress,snapping resistance at Taoyuan and Danyang.Plant height,height of ear-neck,height of gravity center increased significantly and bending stress,stem weight per centimeter decreased significantly with increasing nitrogen application rate in special high yield eco-region.For Tai Lake rice region,plant height,dry weight of three leaves from top increased significantly,and snapping resistance decreased significantly with increasing the rate of nitrogen.Thus increasing nitrogen application reduced lodging tolerance.Physical strength of stem decreased significantly with delaying nitrogen application,but it was beneficial to promoting the development of basal stem diameter and wall thickness.