气候变化背景下河南省冬小麦品种更新特征

利用河南省30个农业气象站1981-2010年共196个冬小麦品种的观测数据和同期气象数据，采用相关分析和回归分析方法，研究了气候变化背景下冬小麦生育期长度、积温需求和产量构成要素等品种更新特征。结果表明：30年来，河南省冬小麦生长季平均气温升高明显，营养生长期增温速率高于生殖生长期，降水量变化趋势不明显。不同区域品种更新的主要特征是出苗-抽穗天数减少（2.8~5.9 d/10a）、抽穗-成熟天数增加（1.3~2.5 d/10a）；完成各生育阶段所需积温（>0℃积温）总体呈增加趋势，其中抽穗-成熟期尤为明显（26~50℃?d/10a）。有效穗和穗粒数与营养生长期长度或同期积温无显著相关，千粒重随生殖生长期延长而显著增加。豫南地区生育期天数比（抽穗至成熟天数/出苗至成熟天数）和同期积温比（抽穗至成熟积温/出苗至成熟积温）随时间增加，积温比对产量变化的解释性高于天数比；豫中和豫北地区生育期天数比随时间增加，但积温比无明显的时间变化趋势，单产提高与生育期天数比增加有关。气候变化背景下河南省冬小麦品种更新特征是营养生长期缩短、生殖生长期延长、千粒重增加，从而提高了产量。

Characteristic of Winter Wheat Cultivar Shift in Henan Province Under Climate Change

Based on the data observed at 30 agro-meteorological stations in Henan Province that include the phenological development and grain yield components of winter wheat and meteorological elements over the period of 1981-2010, the changes in the length of growing season, the requirement of accumulated temperature, and the yield components of winter wheat were investigated. A total of 196 cultivars of winter wheat were planted during this period. Correlation analysis and regression were used to perform the investigation. The results show that mean temperature in wheat growing season increased significantly. The increase in vegetative period was more pronounced than in reproductive period. In contrast, precipitation did not show significant trends over the 30 years. Cultivar shift and climate warming shortened the length from emergence (E) to heading (H) significantly with the rate of 2.8-5.9 d/10a, but the days from heading to maturity (M) increased significantly with the rates of 1.3-2.5 d/10a. Nevertheless, the accumulated temperature (>0℃) to complete the developmental phases increased, particularly in the H-M phase. The increase rates were 26-50 ℃?d per decade. The weight of 1000 kernels increased markedly with the extended H-M phase. However, the spikes and kernels per spike were correlated neither with the length nor with the accumulated temperature (>0℃) in the phase of E-M. A further investigation indicated that both the ratios of H-M to E-M in days and in accumulated temperature in southern Henan, and the ratio of H-M to E-M in days in central and northern Henan increased with time. The variability of grain yield in southern Henan was better explained by the ratio in accumulated temperature than in days. In central and northern Henan, the grain yield was positively correlated with the ratio of H-M to E-M in days. The cultivar shift of winter wheat over 1981-2010 in Henan Province was characterized by shortening vegetative period, extending reproductive period and improving the weight of 1000 kernels under climate warming.