Effects Of Seaweed Extract On Drought Resistance And Nutrient Uptake Of Apple Seedlings Under Drought Stress

In 2018-2019,the annual apple dwarfing stock M9T337 seedlings were used as the test material to study the effects of seaweed extract on the drought resistance nutrient absorption of apple seedlings under different degrees of drought stress and the comparison of the drought resistance effect of seaweed extract with salicylic acid and abscisic acid under drought stress.The main research results are as follows:1.Different degree of seaweed extract of apple seedlings under drought stress drought resistance and nutrient absorption of potted plant control water simulation the influence of drought stress,set the normal water supply?CK?,moderate drought stress?MD?,moderate drought stress+water?MD+W?,moderate drought stress+seaweed extract?MD+SE?,severe drought stress?SD?,severe drought stress+water?SD+W?,and seaweed extract+seaweed extract?SD+SE?were set.The results showed that drought stress inhibited the vegetative growth of apple seedlings was the photosynthetic characteristics and nutrient uptake,and with the augmentation of the degree of drought stress and increase compared with drought stress treatment,using extract significantly increased the fertile of Marine alga was superior to spray photosynthetic rate antioxidant enzymes activity and osmotic regulation substances content,alleviated the drought stress performed inhibition;Under different degrees of drought stress,the alleviating effect of seaweed extract was different.Under moderate drought,the growth?dry weight?of seaweed extract recovered 25.2%,while under severe drought,it only recovered 18.5%.2.Effects of algal extracts salicylic acid and abscisic acid on growth resistance and nutrient absorption of apple seedlings under drought stress,potted water control method was used to simulate drought stress,and sixtreatments of normal water supply?CK?,severe drought?DS?,water spraying?W?,salicylic acid?SA?,abscisic acid?ABA?and algal extract?SE?were set.The results showed that spraying salicylic acid abscisic acid and seaweed extracts have promoted the seedling growth and nutrient uptake under drought stress,improved the photosynthetic pigment content and net photosynthetic rate,stomatal conductance and intercellular CO₂ concentration,transpiration rate,and raised the blade superoxide dismutase?SOD?,peroxidase?POD?catalase activity and ascorbic acid peroxidase?POD?activity and soluble protein and proline content of osmotic regulation substances,reduce the content of malondialdehyde,effectively relieve the damage of drought stress.Compared with salicylic acid and abscisic acid,algae extract alleviated the biomass?dry weight?by 20.3%,salicylic acid and abscisic acid by 13.5%and 16.9%respectively,and the seaweed extract had the best effect.