Effects Of Drought Stress On Seed Germination And Physiological Characteristics Of Seedlings

Drought is one of the most serious disasters in nature.The frequency of occurrence in China has been increasing year by year,which has seriously restricted the growth and development of plants.Therefore,it is of great significance to study the physiological,biochemical and morphological aspects of plants under drought stress..Physalis alkekengi L.is a perennial herb in the Solanaceae family that has long rich nutrition and certain medicinal value.In this paper,PEG-6000(0,5%,10%,15%,20%,30%)was used to simulate drought stress and artificial water control(20-25%,40-45%,60-65%,80-85%)Then the germination characteristics and physiological and biochemical characteristics of seedling were studied under drought condition.The research indicates that:(1)At the concentration of 5% PEG-6000,the germination rate,germination potential,germination index,vigor index and bud length of the seed pulp were significantly increased or decreased compared with the control experiment.When the treatment concentration was more than 10 %,The above indexes and root length decreased sharply with the increase of PEG-6000 concentration.When the concentration of PEG-6000 reached 30%,the indexes of Physalis alkekengi L.seed were all to a very low level.(2)The content of SOD,POD,CAT,Pro and soluble sugar increased first and then decreased with the increase of PEG-6000 concentration.The POD,CAT activity and soluble sugar content of the LiLiTian(LX)reached the highest value at 15% concentration of PEG-6000,while the POD,CAT activity and soluble sugar content of TieBa(TB)were 20%,15% and reached the highest value at 10% of the concentration.When the concentration of PEG-6000 reached 20%,the SOD activity and Pro content of the two varieties of acid seedling reached the maximum.(3)The activity of SOD,POD,CAT and Pro and soluble sugar were significantly higher than those in the control experiment.The leaf length,leaf width,plant height,total biomass,chlorophyll content and drought degree were significantly higher The increase of drought degree increased first and then decreased,and reached the maximum under light drought treatment.The content of MDA reached the maximum under moderate drought conditions.