Studies On The Seed Physiology In Stress Germination And Seed Standard Of Flemingia Philippinensis

Seed germination is a crucial stage in the plant's life cycle,and it is influenced by water and temperature mostly,among several environmental factors.The germination is also effected by quality of the seed.Guangxi is the main producing area of Flemingia philippinensis,however,the research on the Flemingia philippinensis seeds had not been reported till now,although some papers about cultivation techniques was published and a rapid increasing of the market needs of this plant.So it is very important to study the germination characteristic and adapting mechanism on stresses of water and temperature,and to establish seed quality standard for Flerningia philippinensis.The germinating characteristic and physiological-biochemical data of Flemingia philippinensis seed were measured on water stress,high temperature and low temperature stress and cold imbibition stress.It is showed that physiological activities in the seed take great change and with the stronger stress,the greater change takes place.Though the germination rate was not change obviously or the average germinating speed and germinating index was slightly promoted when the stress treat was put on the seeds,the average germinating speed and germinating index would be influence when beyond some stress range. With the increase of the water stress,the activity ofperoxydase(POD ) and superoxide dismutase(SOD),the content of praline and solvable protein rose accordingly,so does the content of solvable sugar within 2%-6%PEG consistence water stress condition.Though the content of accinaldehyde is higher than the contrast in general,it is not correlating positively with stress intensity.The activities of POD and SOD rose with high or low temperature stress during 48h.When the stress was over 48h,the change of POD and SOD activities would not be regular.With the increase of the stress,the solvable protein and solvable sugar could be accumulated.The stronger the stress,the more the content of praline accumulated,especially in low temperature.The accinaldehyde accumulates obviously no matter in low or high temperature in the earlier germinating stage.Under cold imbibition stress condition,the germinating characteristic and physiological-biochemical data was lower than contrast obviously.According to analysis,we think that Flemingia philippinensis is most sensitive to cold imbibition stress,and then was water stress.In temperature stress it was more sensitive to low temperature than high temperature stress.On the found of the collecting seed of Flemingia philippinensis in Guangxi,we research the methods for some items including:sampling,the purity analysis,weight determination,determination of moisture content,verification of species,the test germination,test for vitality and seed health test.Base on these methods the rules for Flemingia philippinensis seed was established.By K-means cluster the four items,the percentage of germination,the weight of 1000 seed,the moisture content of seed and the purity of seed,we made the standars of quality grading with these four items for Flemingia philippinensis seed...