The Effects Of Low Temperature On The Growth And Macro And Middle-nutrient Elements Absorption Of Pepper (Capsicum Annuum L.) Seedlings

Nowadays the protected agriculture development is estimated based on the review of its product processing and the international trade in the country. Pepper is one of the most important vegetables in protected cultivation. Pepper (Capsicum annuum L.) grows in warm climate and can not tolerate low temperature. Chilling stress during winter and spring usually causes injuries of pepper and then has a significant negative effect on production of this crop. Low temperature is key limited factors in cold season production. Under low temperature, previous studies about pepper only limited on growth of seedlings, there is litter profound study about effects of mineral elements absorption. In cold season cultivation, low temperature often adversely affects growth of pepper. It is worthy to be immediately about these key issues.Longjiao NO.2 peeper seedlings,were employed under different temperature in this experiment. Combined with winter-spring modern green-house temperature condition, Pepper seedlings plant growth and development and mineral elements absorption were analyzed and measured, so to provide rationale for pepper mineral nutrients and temperature management in protected cultivation in cold season. We got following major conclusions:Temperature affects fresh weight and dry matter accumulation of peeper seedlings. Fresh weight and dry weight of peeper seedlings decreased under low temperature. Under the temperature (15℃/9℃) the weight decreased more obviously, under the temperature (10℃/5℃) the growth of peeper seedlings nearly stop, the peeper seedlings could be tolerated the injury of stress at this temperature. The root activities of peeper seedlings is also decreased significant under the conditions of different low temperature.Chlorophyll content decreased under low temperature. The content of chlorophyll in all pepper leaves treated by low temperature of 15℃/9℃decreased. The soluble sugar and soluble protein increased under low temperature. The changes of the content of soluble sugar and soluble protein before and after the low temperature treatment show that the indexes are closely related to pepper's cold-resistance ability.The nutrient contents of pepper seedlings are obviously different with different temperatures, and nutrient contents are obviously different of different organs. Taken as a whole, the root system of nitrogen, calcium and magnesium content in the lower temperature reduced at a certain temperature range(9℃-28℃), and the roots of P and K concentrations decreased with decreasing temperature trend; The stems nutrient content increased with lower temperature except P. leaf N, P, and K content decreased with lower temperature, and the Ca content in leaves is increasing.The elements of K,Ca and Mg are adversity osmolyte accumulation as a plant. In a certain temperature rang(e9℃-28℃), pepper seedlings K content in roots increased, stem K, Ca, Mg and leaf Ca content increased,they can improved cold resistance.