Effects Of Low Temperture On Root Exudates Of Wheat Seedling And Chemical Properties In Rhizosphere Soil

This paper made use of pot experiment, with four varieties of Henan large-scale cultivation asexperimental materials, studied the influences of wheat seedling root secretion and rhizosphere soilphysical properties under low temperature treatments.Based on the above test results, choose one lowtemperature sensitivity is the larger of the two varieties from the test, studied effects of wheat seedlingroot secretion and rhizosphere soil physical properties under low temperature treatments, so as toreveal the secretion of wheat root in the rhizosphere environment in the role of low temperaturedamage relief and mechanism. The main conclusions of this study were as follows:1. Low temperture stress reduces the dry matter accumulation, the root-shoot ratio and relativegrowth rate of the root and the ground part of wheat seedling, and T₃（-10±3℃） deal with for3days,the dry matter accumulation and root and the ground part of relative growth of various varieties reacha minimum. The reduces of the root-shoot ratio and root of the relative growth rate of semi-wintervarieties were more obvious than the weak spring varieties under low temperature stress, The reducesof dry matter accumulation in the weak spring varieties were more obvious than the semi-wintervarieties. The root relative conductivity of the varieties increases, and the root relative conductivity ofthe semi-winter varieties were lower than weak sping after the low temperature treatments.2. Under low temperature stress, the contents of soluble sugar, soluble protein, available aminoacid, total hydroxybenzene in root exudates of wheat seedling increased. With temperture decliningthe contents of exudates show the trend of first increase then reduce, T₂（4℃） deal with for3days ismore advantageous to the induction of wheat root secretion of soluble protein, total phenol, free aminoacid; T₃（-10±3℃） deal with2days is more advantageous to the induction of wheat root secretionsoluble sugar. Overall, various components that the semi-winter varieties root exudated wassignificantly higher than the weak spring varieties. At that, wheat seedlings resisted low temperaturestress by the root secreting soluble protein, total phenol, free amino acids, thus improving the patientof low temperture stress. 3. Under Low temperature stress, wheat seedling root exudates had a certain activation on soilphosphorus, and the activation will be inhibited when the temperture declined and the processing timewas prolonged, and T₃（-10±3℃） deal with them for2days, the activation function on soilphosphorus was obvious （P<0.05）. Rhizospheric soil available phosphorus content of semi-wintervarieties is higher than weak spring cultivars, increasing of soil nutrient availability ensured the wheatnormal growth, and improved resistance of wheat seedlings under low temperature stress.4. Wheat seedling root secretion significantly eased the activation of soil invertase, soil catalaseand soil amylase under low temperature stress, with temperature reducing, varieties showed differenttrends, and semi-winter yumai49-198rhizosphere soil enzyme activity is higher than other threevarieties. But when temperature decreased, the rhizosphere soil enzyme activity of varieties dropped,all reached a minimum at the condition of T₃treatment.5. Coronatine treatment can increase root dry weight and dry matter accumulation of wheatseedling, and the increase of semi-winter wheat root dry weight is more obvious. With contrast,function that coronatine treatment promoted the growing of root was more abvious.under lowtemperature stress. With sprayed coronatine, root dry weight of two varieties increased to10%-175%higher than control, dry matter accumulation increased to5%-263%higher than control. To acertain extent, coronatine improve the content which wheat seedling root secreted soluble protein,soluble sugar, free amino acid, total phenol. Had increased the rhizosphere available nitrogen andavailable phosphorus, and enhanced the rhizosphere soil enzymes activity and reduced the relativeconductivity of root, which reduced the damage of the low temperature on root membranepermeability, thus maintaining the stability of cell plasma membrane and integrity and enhance theability which wheat seedlings resisted low temperture stress.