Effects Of Rare Earth Gd On Tomatos Seedling Growth Under Calcium Nitrate Stress

The vegetable industry has developed rapidly since Chinese implementation of the "vegetable basket" project, especially the protected cultivation. As one of the most important part of Vegetable industry, the development of protected cultivation has become an important symbol of contemporary vegetables industry modernization. Yet, in a protected vegetable cultivation, crops often encounter improper temperature and light conditions, and due to the unreasonable of continuous cropping and fertilizer application, salt in the greenhouse soil accumulated at the same time, which result in the increasing seriousness of secondary salinization. This article focus on the practical problems existing in the tomato planting on the fruit of "903 Shanghai" tomato, try to explore the rare earths gadolinium influence on tomato seedling growth under calcium nitrate stress, aims to provide theoretical foundation and basis for tomato planting technology. The main results were as follows:1. Rare earth gadolinium on tomato seedlings under calcium nitrate stress vegetativegrowth: the influence of calcium nitrate under duress tomato seedling growth was significantly inhibited, the plant height, fresh weight and dry weight were significantly lower, the growth, spraying on the leaf of rare earth and calcium nitrate stress after gadolinium, tomato seedling fresh weight, dry weight were improved than control, rare earth gadolinium helps relieve the stress of the calcium nitrate on tomato seedling growth inhibition, promoted the seedling growth, reduce the damage calcium nitrate stress on plant.2. Rare earth gadolinium tomato seedlings under stress of calcium nitrate oxidation system: the influence of calcium nitrate stress to 9 days, tomato seedlings of leaf SOD, POD, CAT activity were significantly decreased, and the leaves malondialdehyde (MDA) content and membrane permeability increased significantly, the leaf membrane lipid peroxide level significantly increased, stability of cell membrane damage. Tomato seedlings under calcium nitrate stress after spraying on the leaf of rare earth gadolinium, which can effectively improve the activity of SOD, POD, CAT, inhibit calcium nitrate seedling leaves under stress of membrane lipid peroxidation damage, electrolyte leakage and MDA accumulation is reduced, membranous peroxide level is reduced, maintain the normal physiological metabolism, promote the improvement of the overall antioxidant capacity in cucumber seedlings, effectively relieve calcium nitrate stress damage.3. Rare earth gadolinium on tomato seedlings under calcium nitrate stress the influence of soluble protein, soluble sugar and proline:calcium nitrate under duress in the tomato seedlings of leaf proline, soluble protein, soluble sugar content increases, spraying on the leaf of rare earth and calcium nitrate stress after gadolinium tomato seedlings, into a increased the tomato leaf soluble protein, soluble sugar and proline content, thus for tomato seedlings in the growth and development to provide additional calcium nitrate stress down osmotic regulation ability, improve the resistance of tomato.4. Rare earth gadolinium effect on photosynthetic characteristics of tomato seedlings under calcium nitrate stress:compared with normal controls, Ca (NO3) 2 stress under the 9 d chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) are dropped significantly, a significant rise in intercellular CO2 concentration (Ci), seriously affected the tomato seedling photosynthetic performance. Spraying Gd2 (CO3) 3 treatment reduced the Ca (NO3) 2, under duress, improve the utilization efficiency of light energy, alleviate the photoinhibition of cucumber plants, maintain high photosynthetic performance, so as to reduce the Ca (NO3)2 damage to tomato seedling.