Effects Of Saline - Alkali Conditions On Growth And Development And Carbohydrate Metabolism

Melon variety named‘Jinfei’ was taken for tested materials,South China AgriculturalUniversity fruit and vegetable nutrition formula was for criteria, matrix soilless cultivationmethods was base of the test in2014. The research was seted four salt and alkali levels: T1(25mmol L-1), T2(50mmol L-1), T3(75mmol L-1), T4(100mmol L-1), water as CK. Indifferent periods of growth and development of melon, by measureing melon morphology index,material accumulation index, physiology indicators and related indicators of sugar metabolism,studied muskmelo plant growth and development, changes in physiological characteristics,melon growth and quality under salt and alkali stress. We have studied in the effects of melonsugar mechanism under salt and alkali conditions.The test was designed to provide a theoreticalbasis for the development of melon characteristic industry under salt and alkali soil, to provide atheoretical reference for using a large area of Daqing soda saline land. The results showed that:1. In the seedling stage, the low salt and alkali stress concentration decreased plant height,stem diameter, root and shoot dry matter accumulation, and relative water content, sugar contentin leaves, leaf sucrose content of melon but high-salt and alkali stress concentration promote.Melon chlorophyll content, root vigor and vitality nitrate reductase was promoted in lowconcentration but high concentration inhibited in the early post-processing, each concentrationgradient of salt and alkali stress showed inhibition at the press time of twenty days andtwenty-five days. Inhibitati of salt and alkali stress on root volume and increased leaf areadepended on concentration and stress duration while salt and alkali stress increased the drymatter distribution ratio. Melon soluble sugar content at each salt concentration gradient stressshowed for the promotion in the treated five days to twenty-five days.2. In the runner develpment period, chlorophyll content, nitrate reductase activity, starchcontent of melon in the each salt and alkali stress concentrations exhibited suppressed. Melon inth salt and alkali stress was promoted protective enzymes SOD, POD, CAT activity while saltand alkali stress increased the soluble sugar content and enzymes activity in the latter part of thehigh concentration of100mmol﹒L-1treatment. Low concentrations promoted reduce of sugarcontent and sucrose content of melon vine leaf but high salt and alkali concentrations inhibitedthe content of reducing sugars and sucrose in the late time. 3. In the fruiting period, melon at different concentrations of salt and alkali stress tested thatlow concentration saline stress promoted chlorophyll content, leaf reducing sugar and sucrosecontent in early period time while high concentrations and in post time various concentrationsinhibited the three index content in leaves. Each concentration of salt and alkali stress decreasedthe leaf nitrate reductase activity, fruit length, fruit diameter, single melon weight, leaf and fruitsucrose invertase (SI)、 sucrose synthase (SS) activity and improved leaf SOD activity, PODactivity, CAT activity, soluble sugar content, sucrose phosphoate synthase (SPS) activity blades,soluble solids content, fruit glucose, fructose and reducing sugar content of fruit, fruit sucrosecontent, the soluble sugar content, starch content of fruit, fruit SS and SPS activity.In earlyperiod time, different concentrations of salt and alkali stress promoted melon leaf starch content,leaf SI activity, titratable acid content. In addition to fruit sucrose, soluble sugar and starch, eachindex under100mmol﹒L-1salt and alkali stress showed significant inhibition in the thirty-fivedays after pollination.