Physiological Effects Of Antitranspirant And Super Absorbent Polymer On Heat And Drought Resistance Of Phyllostachys Violascens Forest

Heat and drought is an important limiting factor for high and stable yield of agroforestry. In order to prevent or alleviate the influence of heat and drought on the production of Lei bamboo forest, we took Lei bamboo forest in the same environment as the experimental area and selected four pieces of 10 m * 10 m samples, used the natural high temperature and drought during August and September, by setting blank control(CK), spraying on the leaf antitranspiran(A), furrow application super absorbent polymer(B), spraying on the leaf antitranspiran plus furrow application super absorbent polymer(C) 4 treatments, to study on physiological influence of antitranspiran and super absorbent polymer on heat and drought resistance of Lei bamboo forest and analyze their effects on preventing and relieving the injury of high temperature and drought of Lei bamboo forest, hoping to provide practical reference for bamboo forest production. Main results and conclusions are as follows:(1)Under heat and drought, Lei bamboo forest soil relative humidity and leaf relative water content vary with high temperature and drought continued falling, but the RH and RWC of the treatments which applied antitranspiran and super absorbent polymer were obviously higher than the same period(22d)of comparison,A,B,C three treatments were respectively 19.0%,21.5%,24.5% and 19.6%,27.3%,30.3% higher than CK,and the falling rate of these two indicators was less than CK.(2)Under heat and drought, the REC and MDA content of Lei bamboo forest leaves were positively correlated related to the changing trend with high temperature and drought degree within a certain range, compared with the initial CK respectively increased by 49.3% and 23.3%. But the REC(22d) of the treatments which applied antitranspiran and super absorbent polymer decreased by 5.73%, 8.61% and 10.22% compared with the comparison, and MDA content(8d) decreased by 5.4%, 6.7% and 8.7%,which showed that REC and MDA content were relieved to increase by the application of antitranspiran and super absorbent polymer.(3)As the heat and drought continued,the soluble protein content from the original 18.9 mg/g up to 24.53 mg/g, then dropped to 22.7 mg/g, Pro content was generally in a rising state, increased 52.4%. The soluble protein content and Pro content of A,B,C three treatments were generally lower than comparison in the same period, especially the Pro content in 8d, 22 d, 15 d and CK were significantly different(P < 0.05).(4)Under heat and drought,the SOD, POD, APX activities of Lei bamboo forest leaves of every treatment were reduced after the first rise trend, but CAT activity was stable after in reducing. 1d-15 d,the protective enzyme activity of A,B,C three treatments was mostly lower than the same period of CK; and when 22 d, the difference was not significant among A, B, C treatments(P>0.05). It indicated that the application of antitranspiran and super absorbent polymer, to a certain extent, can slow the damage of heat and drought. Different changes of the protective enzyme activity also confirmed that, as a whole, the protective enzyme system maintained certain dynamic balance under high temperature and drought.(5)Under heat and drought, chlorophyll content of CK decreased 19.1% compared to the early,but A, B, C three treatments decreased less than CK; carotenoid content of every treatment in early rise to suppress damage, but late gradually decline as the high temperature and drought continued. When 20 d,the Pn of A,B,C three treatments were 1.6 times, 1.3 times and 1.8 times of CK, the difference was significant(P<0.05); Tr,Gs of A, C treatments were lower than the same period of CK, B treatment was higher than comparison, but the differences between the groups were not significant(P > 0.05); the WUE of A,B,C treatments were respectively 79.6%、23.8% and 86.5% higher than the same period of CK, significantly different(P<0.05). Similarly, the Fv/Fm,ΦPSII,qP of A, B, C three treatments were significantly higher than that of CK, but the NPQ value was less.Under heat and drought, spraying on the leaf antitranspiran(1:800)and furrow application super absorbent polymer(1 kg/100m2)can reduce the soil relative humidity and RWC decreased, relatively increase WUE and maintain the protective enzyme activity of dynamic balance, reduce the REC and MDA content rising amplitude, improve the photochemical quantum efficiency and photosynthesis of Lei bamboo and other ways to enhance the ability of Lei bamboo forest resistance to heat and drought, and especially in the superposition of two kinds of reagents applied effect was relatively better.