Effect Of Water Under Sub-low Temperature On Nutrition Absorption And Physiological Of Tomato In Seedling

With potted tomato plants in greenhouse as the experiment material, and with the plantunder normal temperature(18－30℃) as control treatment, research the influence of youngtomato plants under sub-low temperature (4－20℃) and supplementary60%,80%,100%and120%of ET irrigation amount on the plant growp、physiological nutrition absorption andphysiological. reveal the moisture of the tomato seedling crops grown at low temperaturenitrogen and potassium nutrient absorption and distribution characteristics, provide the basisfor nutrient management and water-saving irrigation of greenhouse tomato cultivation, we arefollowing major conclusion:1.compared with normal condition, and under the four conditions respectively, assupplementary water drop, tomato seedling dry matter accumulation is leaf>stem>root.thestem dry matter accumulation is reduce by the supply irrigation amount is. root and leaf drymatter accumulation reach biggest at supply100%ET irrigation amount. the root, stem andleaf of dry matter accumulation decreased obviously; Dry matter to leaf in distributionproportion decreases, and to stem and root of the allocation proportion increases.2.Compared with normal condition, the sub-low temperature tomato seedling plants drymatter accumulation is、N and K element content was lower and leaf water potential reduce,under sub-low temperature (4－20℃) and supplementary100%of ET irrigation amount theyare the biggest. leaf water potential increase improve nutrition absorption and transport andincrease contained. Water under sub-low temperature reduce tomato seedling growth, in thisway,the total nitrogen element drope. N elements by the influence of the water amount islarger, the low temperature to K element of the total amount of great influence. At the end oftreatments, N:P:K is1：1：0.03（NW）、1：:0.90：0.03（NW2）、1：1.18：0.03（NW3）、1：1.18：.03（NW4）、1：1.40：0.02(LW1)、1：1.26：0.02(LW2)、1：1.02：0.02(LW3)、1：0.95：0.95(LW4)。On the sub-low temperature condition, supply100%ET water to thebenefit the tomato in seedling adapt to sub-low temperature environment.3at the begin of treatment, NKP transport to blade decrease, contrast the stem and root.As the moisture decreased, blade leaf NK increase, contrast the stem and root. by the time longer NPK transport to leaf increase. As the moisture increased, blade NK increase, As themoisture decreased,root NK increase.4.Compared with normal condition, and under the four conditions respectively, sub-lowtemperature reducing nitrate reductase activity, the content of soluble sugar rise, solubleprotein content decrease, photosynthetic rate (Pn) decreased，water use efficiency rise,Fv/Fm、ΦPSII and qP increased slightly. The influence of temperature on the young tomatoplants more than water.To sum up, the low temperature water stress inhibited the growth of tomato seedlings,which affected the NPK in the plant total, tomato seedlings by adjusting the content ofosmoregulation substance and increase water use efficiency to maintain normal growth.Optimal supply100%ET water under mild hypothermia is conducive to the growth of tomatoseedlings and the absorption of nutrients, supply100%ET water and low temperature canincrease the tomato seedlings to low temperature resistance.