Effect Of Saline-alkali Stress On Growth And Physiological Ecology Of Rice In Different Concentrations

The pot culture experiment was conducted to study effect of saline-akali stresson growth and physiological eology of rice in different concentrations and Chang bai9as material. By studing the different concentrations （10concentration gradients）saline-akali stress on rice growth, photosynthetic characteristics, biological yield,yield components and changes of main iorns in soil, to discuss the influencingmechanism of saline-akali stress on rice in different concentrations. The mainlyresults are as follows:1. Effect of saline-akali stress on growth and dry matter accumulation of rice indifferent concentrations were significant. Plant height, tiller number, leaf area ofsaline treatment were lower than CK in the whole growth period of rice. It made thebiomass and yield falling. Saline-akali stress had inhibitory effects of biomassaccumulation in each growth period, at the same time, saline-akali stress also inhibitear number per unit area, grain numbers per spike and1000-grain weight,and it resultthe reducing of yield. The morphological index of processing A (soil salt content was2.20‰) were lower than CK (soil salt content was1.10‰), but the difference was notsignificant. It showed that there was no significant effect on growth and yield of ricewhen the soil salt content was2.20‰, with the strengthening of salinity stress, thedifference declined significantly.2. Effect of saline-akali stress on photosynthetic physiological and ecology ofrice in different concentrations showed that saline-akali stress made Pn reducing ineach time point in a day, with the concentration of salinity stress, the falling greater.Transpiration rate, stomatal conductance, intercellular CO2concentration of saltconcentrations were lower than CK. The chlorophyll content and POD of saline-akalitreatment were lower than CK in whole growth period of rice. The chlorophyllcontent of saline-akali treatment was characterized by CK>A>B>C>D>E>F in variousperiods, the soluble sugar content increased with the concentration of salt conten injointing stage. With the enhancement of salinity stress, the soluble protein content wasreduced after the first rise trend. MDA content increased along with the enhancementof salinity stress. The POD activity of saline treatment was lower than CK.Under theexperiment condition, each photosynthetic index and physiological index of processing A (soil salt content was2.20‰) was lower than CK (soil salt content was1.10‰), the difference was not significant. It showed that there was no significantinfluence on photosynthesis and physiological function of rice when soil salt contentwas2.20‰. With the strengthening of salinity stress, the difference declinedsignificantly.3. Effect of saline-akali stress on the soil eight iron before and after planting rice indifferent concentrations showed that the content of CO32-、HCO3-、SO42-、Cl-、Ca2+、Mg2+、K+、Na+was correspondingle reduced, and the reduction varied bysaline-akali stress. The content of CO32-、HCO3-、Na+reduced with the increaseof salinity,and the heavier stress,the more reduction.The content of SO42-、Ca2+、Mg2+in soil showed a trend of decline before planting rice, but the extent of itsdecline had no rule with the strengthening of salinity stress.A comprehensive analysis found that each shape index, photosynthetic index andphysiological index of processing A was lower than CK under the experimentalcondition, and the difference was not significant;When the soil salt content was morethan2.20‰, each index declined significantly compared to CK. It showed that whenthe soil salt content was less than or equal to2.20‰, it was suitable for planting rice.Thus, the index can be used as planting rice in the soda soil and saline-akali soilimprovement and the comprehensive utilization.