| Under the background of global warming, annual average temperature of surface increased by 1.1℃, and the rate of warming was 0.22℃ 10a-1 in China last 50 years.It also changed markedly, and warming increased by 0.26-0.29℃ 10a-1 in Jiangsu province last 50 years.Winter wheat is one of the major food crops in China, and is sensitive to temperature. So the effect of climate warming on winter wheat production is inevitable. In order to comprehend the effect of climate warming on the yield and growth of winter wheat, Data of 50 years of winter wheat in south, middle and north of Jiangsu province were chosen to study. Correlation and regression analysis was make out to reveal the response of winter wheat growing development process and yield to climate warming, based on the records of wheat yield and Climate factors(temperature and precipitation) over the period 1961-2010 and datasets of the development process of wheat during 1961-2010 in the three areas. A field experiment was conducted to study the effects of all-day warming on the growth, development and yield of winter wheat cultivars bred in different years under free air temperature increase (FATI) in south (Danyang) and north (Xuzhou) of Jiangsu province. The main conclusions were as follows:1. It was found that over these fifth years, the diurnal mean, minimum and maximum temperatures during wheat growing season increased in south, middle and north of Jiangsu province. No significant change in the precipitation was found. The warming of minimum temperature was higher than that of maximum temperature. The most obvious warming was occurred in the north, followed by that in middle, then south. Climate factors of each decade have changed dramatically, from 1961 to 2010 in Jiangsu province. Tavg, Tmax and Tmin increase significantly after 1980s in south, middle and north of Jiangsu province.2. Growth duration of winter wheat was shorted, which mainly shortened vegetative period, but the reproductive stage extended, nearly 50 years in Jiangsu province. Sowing date of winter wheat was significantly delayed, Heading and maturity date had significant trends in advance, from 1960s to 2000s. The advanced days of heading date was more in north than in south of Jiangsu province, but the advanced days of maturity are more in south than in north of Jiangsu Province. Growth period of winter wheat shorten by 2.4,3.8, and 1.5 d each decade in south, middle and north of Jiangsu province, respectively. With the temperature of Tavg rising 1℃, growth period shorten by 5.4,9.6 and 3.5 d, in three areas, respectively. Trends of shortening were significantly in south and north, and were very significant in the middle of Jiangsu province.3. Growth periods of different cultivars under FATI were all shortened, averagely by 3.2 and 4.1 d in Xuzhou and Danyang, respectively, mainly due to shortened pre-heading stages (averagely by 7.5 and 8.5 d in Xuzhou and Danyang, respectively) and prolonged filling stage (by average 4.3 d).4. Statistical yield of winter wheat had increased from 1960s to 2000s in Jiangsu province, south and middle of Jiangsu province had a very significant trend. Except for 1960s cultivars in Xuzhou, grain yield increased under FATI, averagely by 21.0% and 14.1% in Xuzhou and Danyang, respectively. Grain number per spike of all varieties were increased, and 1000-grain weight, in addition to 1960s varieties fall in Xuzhou, others were improved. Statistical analysis of variance showed that warming altered the contribution of yield components to yield. And there are regional differences. Warming impacted the change of production by grain number per spike and effective spikes in Xuzhou, while 1000-grain weight in Danyang. Warming on yield is good or not, which also affected by varieties, regions and other climatic factors. Except for 1960s variety yield in Xuzhou, other varieties increased with warming, the more obvious the variety of the old yield increased more,1960s variety production increased the most in Danyang... |
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