模拟增温对半干旱雨养区春小麦物质生产与分配的影响

为了明确未来气候变化对半干旱区春小麦生产的影响，了解增温条件下春小麦不同生长阶段物质生产的响应特点以及光合产物在不同器官中的分配特征，利用开放式红外增温系统设置不同的温度梯度，即不增温（对照）、增温1和2℃，模拟田间增温对春小麦物质生产与分配的影响。结果表明：温度增加，春小麦发育加快，全生育期明显缩短，增温1和2℃，比对照分别缩短7和11 d；从各器官干物质生产来看，相对于对照，在增温1、2℃处理下，叶干物质质量在三叶期分别增加了11.23%和27.49%，在拔节期及其以后分别平均降低了20.12%和30.83%。茎干物质质量在拔节期及其以前分别平均增加了17.30%和30.30%，拔节期以后分别平均降低了13.19%和22.09%。根干物质质量在孕穗期及其以前分别平均增加了10.26%和23.30%，孕穗期以后分别平均降低了15.79%和26.05%。穗干物质质量分别平均降低16.43%和29.00%；增温处理下春小麦物质生产随时间的响应规律主要是由净同化率的变化所致；从各器官干物质分配来看，与对照相比，增温1、2℃处理下，春小麦叶和穗干物质质量占全株干物质质量的比例在整个生育期分别平均下降了8.32%、12.01%和0.56%、3.40%，且增温幅度越大，下降的越多。增温1、2℃处理下，茎和根干物质质量占全株干物质质量的比例在整个生育期分别平均增加了3.92%、6.25%和3.86%、8.71%，且增温幅度越大，增加的越多。结果为中国半干旱区春小麦对全球气候变化下的敏感性及适应性研究提供理论参考。

Effects of simulated warming on dry matter production and distribution of rainfed spring wheat in semi-arid area

In order to predict effects of future climate change on spring wheat production, and to understand the response characteristics of dry matter production in different growing period of spring wheat and the distribution characteristics of photosynthetic products in different organs, we conducted a field infrared temperature-increasing simulation experiment with the applications of free air temperature increased system (FATI) to investigate the effects of air temperature increases (non-warming, warming 1 ℃ and warming 2 ℃) on dry matter production and distribution of rainfed spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration (35°35′N, 104°37′E). The results showed that with the increase of temperature, growth and development of spring wheat accelerated, the growth duration was shortened significantly, Warming of 1.0 and 2.0 ℃shortened the growth duration by 7 days and 11 days, respectively. Appropriate temperature increases can promote the growth of crops. However when temperature increased more than the optimal temperature for wheat growth, the temperature could become a factor limiting the growth. Based on the dry matter accumulation in various organs of spring wheat, warming of 1.0 and 2.0 ℃ increased leaf dry matter weight by 11.23% and 27.49%, respectively at trefoil stage. In comparison, during and after jointing stage, warming of 1.0 and 2.0 ℃ decreased leaf dry matter weight by 20.12% and 30.83%, respectively. During and before jointing stage, warming of 1.0 and 2.0 ℃ increased stem dry matter weight by 17.30% and 30.30%, respectively. In contrast, after jointing stage, warming of 1.0 and 2.0 ℃ decreased stem dry matter weight by 13.19% and 22.09%, respectively. During and before booting stage, warming of 1.0 and 2.0 ℃ increased root dry weight by 10.26% and 23.30%, respectively. But, after booting stage, warming of 1.0 and 2.0℃ decreased root dry weight by 15.79% and 26.05%, respectively. Warming of 1.0 and 2.0 ℃ decreased panicle dry weight by 16.43% and 29.00%, respectively. During and before jointing stage, warming of 1.0 and 2.0 ℃ increased aboveground dry weight and total dry weight by 11.19%, 20.61% and 11.46%, 21.79%, respectively. However, after jointing stage, warming of 1.0 and 2.0 ℃ decreased aboveground dry weight and total dry weight by 16.43%, 27.15% and 15.96%, 26.26%, respectively. The time response curves of dry matter production to temperature at different growth stages of spring wheat were basically consistent with the time response curves of NAR and LAI, which all increased first then decreased. The response pattern of the matter production of spring wheat under different warming treatments was mainly caused by the change of NAR. From the dry matter distribution of various organs of spring wheat, at trefoil, jointing, booting, heading, flowering, grain filling and milk ripe stage, warming of 1.0 ℃ decreased the ratio of dry matter of leaf to total dry weight by 0.24%, 14.28%, 4.63%,11.23%, 12.66%, 6.83%, and 8.39%, respectively. However, with warming of 2.0℃ the decrease for each growth stage was 1.35%, 19.46%, 8.08%, 11.82%, 18.23%, 12.56%, and 12.58%, respectively, The warming of 1.0 ℃ increased the ratio of dry matter of stem to total dry weight by 0.94%, 9.55%, 0.20%, 5.37%, 4.62%, 2.67%, and 4.07% for different growth stages, respectively. In comparison, the warming of 2.0 ℃ for the ratio was 2.55%, 12.01%, 2.19%, 6.86%, 8.33%, 5.37%, and 6.46% for each growth stage, respectively. Warming of 1.0 ℃increased the ratio of dry matter of root to total dry weight by 0.43%, 3.11%, 10.45%, 1.59%, 5.25%, 2.96%, and 3.21% each for different growth stage. But warming of 2.0 ℃, the ratio for different growth stages was 3.73%, 8.96%, 23.54%, 2.75%, 10.49%, 5.33%, and 6.17%, respectively. At booting, heading, flowering, grain filling and milk ripe stage, warming of 1.0 ℃decreased the ratio of dry matter of panicle to total dry weight by 0.46%, 0.69%, 0.90%, 0.37%, and 0.39%, and 9.21%, 2.44%, 3.32%, 0.97%, and 1.07% for 2.0 ℃, respectively. For spring wheat, decrease of dry matter distribution in leaf and the increase of dry matter distribution in root may be due to improving water uptake ability. The research results can give the theoretical references for the sensitivity and adaptability of spring wheat in semi-arid area of China under global climate change.