Effect Of HIDS-K On Seed Germination And Seedling Growth Of Summer Squash Under Low Light

In this experiment,summer squash was used as the experimental material to study the effects of different concentrations of Polyaspartic acid derivative(HIDS-K)on the germination of summer squash seeds and the growth physiology of summer squash seedlings under low light.The main conclusions were as follows:1.In the germination test of s squash,with distilled water as the control,the seeds of summer squash were treated with three concentrations of HIDS-K solution(300 mg·L-1,600 mg·L-1 and 900 mg·L-1)to determine the germination rate,germination potential,germination index,vigor index,dry fresh weight and physiological index.The results showed that the germination power and vigor index of seeds treated with600 mg·L-1 HIDS-K increased by 133% and 100% respectively compared with CK.The content of soluble protein and suger in summer squash buds treated with 600 mg·L-1 HIDS-K was 33% and 56.47% higher than that of the control.The activity of SOD,CAT and POD in summer squash buds treated with HIDS-K was significantly higher than that of the control(P < 0.05).Therefore,in this experiment,600 mg·L-1HIDS-K was the most favorable for the germination of summer squash seeds.2.Under the low light stress of 200 μ mol·m-2·s-1,the Zucchini seedlings were irrigated with 1/3,1/4nutrient solutions mixed with 300 mg·L-1,600 mg·L-1 and 900 mg·L-1HIDS-K solutions respectively,the growth index,photosynthetic index and physiological index were measured.The results showed that the growth potential,seedling growth index,G value,SLA,LMR and LAR biomass of the seedlings treated with the mixture of HIDS-K and nutrient solution were higher than those of the control,and the root growth of the A2B2(1/4 nutrient solution + 600 mg · L-1 HIDS-K)treatment was significantly higher than that of the other treatments(P < 0.05).The contents of chlorophyll a,chlorophyll b and carotenoid in leaves of A2B2 treatment were 15%,6% and 21% higher than those in the control(1/4 nutrient solution),Tr and Pn in leaves of A2B2 treatment were 16-42%,56-64% higher than those in other treatments,and NPQ in leaves of A2B2 treatment was 26% lower than that in the control(1/4 nutrient solution).Compared with the control(1/4 nutrient solution),the activities of SOD,POD and CAT increased by 5%,25% and 46%respectively,and H2O2 decreased by 18%.In conclusion,the combination of HIDS-K and nutrient solution could improve the low light tolerance of summer squash Seedlings,and A2B2 was the best.This experiment will provide some basis for the application of HIDS-K in agriculture.It will be of great significance to promote the seed germination of summer squash and improve the seedling quality of summer squash.