Effects Of Calcium On Growth And Quality Of Ipomoea Aquatica Forsk

Water spinach(Ipomoea aquatica Forsk ) is a member of the morning-glory family,Convolvulaceae,annual or perennial,herbaceous plant.It is a loved vegetable because of its function in the area of dietary and pharmaceuticals.Ca plays an important role on the growth and development of plants,so it has theoretical and practical meanings to investigate the effect of Ca on the growth,development and quality of Ipomoea aquatica.1.'White-seed water spinach','Hunan water spinach','Black-seed water spinach' were used as the test materials,solution culture was applied in the overall experiment.The effect of Ca on the growth,mineral element contents and quality of the three Ipomoea aquatica were investigated at different Ca concentration and different stages.Using the solution with same Ca concentration to culture the three kind of Ipomoea aquatica.The result showed that at the same growth stage,the fresh weight of 'Black-seed water spinach' is significantly higher than 'White-seed water spinach',the fresh weight of 'Hunan water spinach' is the lowest,the optimal Ca concentration on 'Black-seed water spinach' and 'White-seed water spinach' is 60mg·L^-1 and 40mg·L^-1,respectively,the effect of different Ca concentration on the fresh weight of 'Hunan water spinach' is nonsignificant.Under the same Ca²⁺ concentration level,the variance of photosynthesis characteristics were significant among three Ipomoea aquatica,the net photosynthesis efficiency of 'White-seed water spinach' is higher than 'Hunan water spinach' and 'Black-seed water spinach',at certain Ca concentration extents,each kind of photosynthesis characteristics presented the trend of first increased and then decreased as the increasing of Ca concentration.At certain Ca concentration extents,Ca can facilitate enzymatic active,but inactivate enzyme when the concentration is higher than 80 mg·L^-1.Enzymatic active reached to the highest in 60～80mg·L^-1 Ca concentration,the enzymatic active of 'Black-seed water spinach' was higher than 'White-seed water spinach' and 'Hunan water spinach'.2.With the Ca concentration at the ranges of 40～200mg·L^-1,Ca content raised and NO₃^- content decreased gradually as the increasing of Ca.At the Ca concentration of 60 mg·L^-1,the contents of vitamin C and soluble protein is a little higher,the mineral elements were easily to uptake and accumulated.Under the same Ca concentration level,the contents of vitamin C,soluble protein,potassium,Zn,Cu were higher,NO₃^- content was a little lower in 'Hunan water spinach'..The contents of vitamin C and soluble protein are significant higher than the other two Ipomoea aquatica.Ipomoea aquatica have better nutritional quality when the Ca concentration was 60mg·L^-1,the best variety is 'Hunan water spinach'.