Correlation Between Bulk Density And Seed Germination Of Soybeans

Seed formation is the beginning of the next generation of reproductive cycle and the quality of the seed is related to the yield of the crop.Seed vigor is a manifestation of the seed physiological and biochemical basis and molecular properties.At present,it remained to be clarified that how soybean seed bulk density affects seed vigor and germination mechanism.This study was designed to explore the effect of bulk density on the germination mechanism of soybean seeds and provided a theoretical basis how to better store and conserve the germplasm resources of soybean seeds.For this we studied physical properties,chemical composition,germination index and anti-aging and adversity ability(high wet processing of high temperature 40?,100%RH,10%PEG-6000 simulated drought treatment,sand processing)at low temperature of 10?,size of the soybean seed density and the mechanism of seed vigor,germination,and the relationship between the physiological and biochemical indexes and the size of soybean seed density anti-aging ability were analyzed.The main results were as follows:1.By studying soybean seed density and chemical composition,the results showed that the grain structure was compact,hundred grain weight was reduced,seed density was increased however,the bulk density was small.The cultivar with larger seeds were susceptible to deterioration with less vigor and more vitality.2.After artificial treatments,such as high temperature,high humidity,low temperature and drought,the content of the soluble sugar and malondialdehyde(MDA)in soybean seed leaching solution was determined.The results showed that the soybean seed decreased with the increase of bulk density without artificial treatment.After artificial treatment,the contents of the seed leaching solution of the major varieties of seeds were reduced by a small reduction in the content of soluble sugar and malondialdehyde(MDA).The seed vigor of major varieties decreased less;The smaller seeds decreased greatly.3.The results from high temperature + high humidity,low temperature + drought,and three artificial treatments demonstrated that the activities of superoxide dismutase(SOD)and peroxidase(POD)in soybean seeds were increased by artificial treatment while catalase(CAT)was decreased.Under high temperature and high humidity and 10%PEG simulation drought osmotic stress treatment,the CAT activity was lowered.After 10? low temperature adversity treatment,the CAT activity was increased.4.Without artificial treatment,in varieties with large capacity,the germination index and seed vigor was increased,immersion conductivity was reduced.After artificial treatment,the germination index was reduced more in varieties with larger seed,the lower reduction of germination index was observed in varieties with smaller seeds.