The Response To Natural Low Temperature Of Different Wheat Varieties Under Fertilizer Application

With12wheat varieties bred in different years in the Huang-Huai Hai area as experimental materials,this experiment was set in wheat field in Henan Normal University in2012-2013. The experiment wastaken two-foctor split plot design. Fertilization amount was main treatment and set no fertilizer (CK), lowfertilizer (N150kg hm-2，P2O560kg hm-2，K22O60kg hm-) and high fertilizer (N300kg hm-2，P2O5120kg hm-2，K-22O120kg hm); the different generations wheat varieties was secondary treatment and set12levels. The changes of wheat morphological indexes, physiological and biochemical indexes, yieldcharacters of different treatments under natural low temperature were studied. Eventually the change rulesof those indexes were found. Cold resistance identification of12wheat varieties in winter period andturning green period was compared by average membership function values of physiological andbiochemical indexes. Dynamic investigation of physiological and biochemical indexes in heading stage wasalso conducted. The main conclusions of the study were as follows:1. The daily mean temperature of air、soil surface and soil decreased at first, then raised. In March thetemperature rised to20℃continuously; in the middle of April temperatures dropped to5℃continuously.From April17th to25th, the temperature changes were larger. In different spatial levels, effectiveaccumulated temperature of soil surface was higher than that of the air and soil. Negative accumulatedtemperature was gradually decreased with the increasing level of space. For three fertilizer treatments at thesame space level, the difference between effective accumulated temperature and negative temperature wassmall.2. In winter stage, physiological indexes changes of different varieties bred in different years weredifferent. In winter stage, the content of osmotic regulation substances (soluble sugar, free proline andsoluble protein) and SOD enzyme activity of1950-1969’s cultivated wheat varieties were higher. So1950-1969’s cultivated wheat varieties had the stronger cold resistance. But physiological changes of all thevarieties were not consistent. Fertilizer effects on the physiological indexes were not the same. The plantwould resist natural low temperature stress by adjusting the change of physiological and biochemicalindexes. 3. In winter stage, Bima1(1950-1969’s) had stronger cold resistance under different fertilizertreatments. In turning green stage, the cold resistance of Zhengyin1(1970-1979’s), Yumai13(1980-1989’s),Yumai10(1980-1989’s), Yumai54(1990-1999’s) and Zhoumai18(2000-’s) were strong or medium underdifferent treatments.4. In the heading stage, the content of osmotic regulation substances (soluble sugar content, freeproline content and soluble protein content) increased under the chilling injury. With the extension ofrecovery time, their content reduced. The reactions of SOD activity, POD activity and MDA content slowed.SOD activity, POD activity and MDA content were highest after12d restored. At chilling injury of headingstage, osmotic adjustment substances played a major role, and could induce a series of physiological andbiochemical reaction. Enzyme activity played an important role in the recovery process. In chilling injurythe increase of MDA content showed the exacerbation of membrane lipid peroxidation degree, and theplant body had a certain degree injury.5. The yield of Zhoumai18(2000-’s) under the low fertilizer treatment was the highest, and its kernelsof per spike and1000-kernel weight were higher. No fertilizer and low fertilizer could improve the coldresistance of wheat in heading stage and reduce the damage of kernels of per spike and1000-kernel weight.The experimental results showed that Zhoumai18under the low fertilizer treatment（N300kg hm-2，P2O5120kg hm-2，K2O120kg hm-2）were the most effective measures in reducing the low temperature effects inHuang-Huai Hai area.