Effects Of Low Temperature Stress On Wheat After Rice At Jointing And Booting Stage And Its Regulation Measures

The experiment was carried out from October 2014 to June 2016 in the Agricultural Experimental Center of Anhui AgriculturalUniversity.The tested materials were Semi-winter varieties of agriculture 19 and Spring varieties Yangmai 18.The effects of low temperature stress at jointing stage and booting stage on the photosynthetic performance,endogenous protective enzymes and yield of two functional wheat cultivars were studied.6-Amino adenine(6-BA),Salicornia(SA)BRassinolide(BR),Abscisic acid(ABA),Potassium dihydrogen phosphate(KH2PO4)and Paclobutrazol(PP333)were used to study the effects of plant growth regulators on the physiological functions of wheat plants under low temperature stress and regulatory effects.The test results are as follows:1.The effects of low temperature on photosynthetic parameters and endoge nous protective enzyme system in wheat leaves at different growth stagesThe net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci),transpiration rate(Tr)and SPAD were significantly higher in the two functional wheat cultivars at jointing stage and booting stage(POD)and Superoxide dismutase(SOD)were increased.The contents of MDA in the leaves of the Semi-winter cultivars were decreased.The content of MDA in functional leaves was increased,and the difference was significant(P<0.05).The results showed that the influence of low temperature stress on the functional leaf of the spring wheat cultivar Yangmai 18 was greater than that of the Semi-winter cultivar.Compared with different fertility period,it was found that the damage degree of leaves at booting stage was higher than that of jointing stage。2.The effects of low temperature at different growth stages on grain filling dynamics,yield and quality of wheatAt the jointing stage and the booting stage,the grain filling characteristics of the two wheat genotypes were affected to varying degrees.The time of the rapid growth period of grain filling and the time of maximum filling rate were delayed.The maximum grain filling rate and average Grain filling rate,grain number per spike and grain weight per kg were decreased.And the difference between treatments was significant(P<0.05).The results showed that the effect of low temperature stress on the grain filling of Spring wheat cultivar Yangmai 18 was greater than that of Semi-winter wheat cultivar.Compared with the different growth periods,the effect of low temperature stress on grain filling was higher than that of jointing stage.After low temperature treatment,the protein content,wet gluten content and sedimentation value of the two wheat genotypes showed an increasing trend.And the difference between the treatments was significant(P<0.05).The results showed that the grain quality of Yangmai 18 was more affected by low temperature stress than that of tobacco farmers.The results showed that the effect of low temperature stress on grain quality was higher than that of jointing stage.3.The effects of plant growth regulators on photosynthetic characteristics and endogenous protective enzyme system of wheat functional leaves after low temperature stress.The activities of Pn,Gs,Ci,Tr,SPAD,SOD and POD of 6-BA,SA,BR,ABA,KH2PO4 and PP333 were studied in wheat leaves at jointing stage and booting stage after low temperature stress.The activity of MDA in the Semi-winter cultivar was decreased,and the content of MDA in the spring wheat cultivar was increasing.The difference between treatments was significant(P<0.05).The activity of Pn,Ci,Tr,SPAD and POD in wheat leaves was the highest.The content of MDA in Yanmai 19 was the highest,and the content of MDA in Yangmai 18 was the smallest.The activity of Gs and SOD was the highest.The overall performance of spraying 6-BA is better than other growth regulators.4.The effects of plant growth regulators on grain filling dynamics,yeld components and wheat grain quality index after low temperature stressThe results showed that 6-BA,SA,BR,KH2PO4,PP333 and ABA were sprayed on wheat leaves after low temperature stress.Compared with the control of sprayed distilled water,the rapid growth period of grain filling in two wheat genotypes began at the end and the maximum grain filling rate.The average grain filling rate increased by 8.94%,4.88%,5.69%,6.50%,7.32%and 5.69%respectively,and the average grain filling rate of Yanmai 18 was increased an increase of 22.41%,20.69%,21.55%,18.97%,21.55%,18.97%.(P<0.05).The panicle number,grain number per spike and grain weight per panicle showed an increasing trend,and the difference was significant(P<0.05).In general,the effect of 6-BA on low temperature injury is better than other plant growth regulators.The effects of spraying plant growth regulators on the grain quality of wheat genotypes were also affected by low temperature stress.The grain protein content,wet gluten content and sedimentation value decreased,and the difference was significant(P<0.05).Compared with the plant growth regulators,the protein content,wet gluten content and sedimentation value of wheat seeds were significantly decreased...