Response Of Passion Fruit Seedlings To Nutritional Stress

Passiflora eduli sims,also known as egg fruit,the scientific name passion fruit,its edible and medicinal aspects of high social and economic value.With the increasing market demand for passion fruit,the industry is growing in a large area in Taiwan,Fujian,Guangxi,Yunnan,Hainan and Guizhou,among which the main production areas of Guizhou are in southeast Guizhou,South Guizhou and southwest Guizhou.In the growing areas of passion fruit,more managers use passion fruit fertilizer based on experience and overuse or underuse it.It has been found that the lack of a certain element in the growth process of passion fruit specifically shows that the growth of the tree is weak,the ability to resist the external environment is decreased,and the yield and quality are decreased.However,the response mechanism of passion fruit seedlings to nutritional stress is still unclear.In this paper,the graft seedlings of purple passion fruit and yellow passion fruit were taken as the research object.Through the single factor level control method,the stress tests of a large number of elements（nitrogen,phosphorus,potassium）,medium and trace elements（magnesium,calcium,boron,zinc）deficiency and different nutrient levels were carried out.The physiological and biochemical indexes of passion fruit under different nutrient deficiency stress and different fertilization levels were observed and compared,and the response mechanism of white fruit to nutrient stress was discussed,which provided scientific basis for the establishment of fertilizer management measures for passion fruit planting.The results show that:（1）The results showed that the absence of N,P,B and K significantly inhibited the growth of two kinds of passion fruit seedlings,while the absence of Ca,Zn and Mg promoted the growth of yellow fruit seedlings.Under nutritional stress,the absence of any element could inhibit the physiological regulation of passion fruit seedlings and reduce the ability of seedlings to resist adverse external influences.Nitrogen deficiency had the greatest effect on the inhibition of two kinds of passion fruit seedlings.（2）The calculation and analysis of index weights showed that the dry weights of above-ground and underground parts were important growth indexes of Tainong No.1 under nutritional stress.The increment of ground diameter,dry weight of underground part and seedling height were the important growth indexes of Qinmi 9 under nutritional stress.MDA,protein,CAT activity,net photosynthetic rate and POD activity were important physiological indexes of Tainong 1 under nutritional stress and stress.Proline,net photosynthetic rate,SOD activity,CAT activity and superoxide anion O^2-were important physiological indexes of nutrient stress and stress of Qinmi 9.（3）The effects of nutrient deficiency on growth and development of Tainong No.1 were ranked as N>K>B>P>Mg>Ca>Zn;The effects of different nutrient deficiency on the growth and development of Qinmi 9 were ranked as N>K>B>Zn>P>Mg>Ca.（4）The results of principal component analysis showed that 200 mg/L nitrogen had the best growth promotion effect on Tainong 1 and Qinmi 9.160mg/L phosphorus application had the best growth promotion effect on Tainong No.1 and Qinmi No.9.The growth promotion effect of 40 mg/L potassium on Tainong No.1 was the best,and that of 80 mg/L potassium on Qinmi No.9 was the best.The growth promotion effect of 20 mg/L calcium on Tainong 1 was the best,and that of 40 mg/L calcium on Qinmi 9 was the best.The growth promotion effect of 100 mg/L on Tainong No.1 was the best,and that of 50mg/L on Qinmi No.9 was the best.1.8mg/L boron application had the best growth promotion effect on Tainong 1,and 0.9mg/L boron application had the best growth promotion effect on Qinmi 9.The growth promotion effect of 0.15mg/L zinc on Tainong No.1 was the best,and that of 0.3 mg/L zinc on Qinmi No.9 was the best.