Study On The Changes Of Vigor And Optimum Moisture Content Of Wheat Seed Stored At Ultralow Temperature

Cryopreservation refers to the storage technology that germplasm resources were preserved below ultra-low temperature of-80℃. The cold source of ultra-low temperature commonly are ultra-low temperature freezer and liquid nitrogen (-196℃), was used to preserve the germplasm resources and the breeding materials. In this study,5wheat varieties (lines) seeds of Wanmai33, Wanmai48, Yangmai158, Zhengmai9023and W1032(waxy wheat) were selected as materials. Each water level seeds took out adequate samples and stored7days at room temperature or ultra-low temperature (-196℃),set the starting moisture seeds were preserved under room temperature as control(CK),carried out liquid nitrogen cryopreservation test. Seedling growth test, cold water test, accelerated aging test, electrical conductivity test, simulated field germination test, as well as ADH,POD,CAT, SOD,LOX activities test were used to determine the vitality indexes of wheat seeds. Study on the changes of vigor and optimum moisture content of wheat seed stored at ultralow temperature, the main rusults as follows:1. The results of commonly seed vigor indicator testing showed:Five wheat varieties5kinds of moisture grades of seeds, after stored in liquid nitrogen for7d, the main vigor indicator decreased compared with control, the treatment which moisture content exceed12%or below10%declines greatly, the main vigor indicator of treatment which moisture content is12%or10%had no significant difference compared with control.2. The results of enzyme activities testing showed:Five wheat varieties5kinds of moisture grades of seeds, after stored in liquid nitrogen for7d, the declines of seed’s activities of ADH, POD, CAT, SOD and LOX were small, and the most of them had no significant difference compared with control. Five enzyme activities of treatment which moisture content is12%or10%descended smaller and had no significant difference compared with control.3. In Five wheat varieties, the average decline of every vigor indicator of the treatment of10%and12%water content indicated:wheat varieties’ability of Ultra-low temperature resistance from big to small:Wanmai33> Zhengmai9023> Wanmai48> Yangmai158> W1032(waxy wheat). Preliminary view was that keratin and strong gluten wheat’s ability of Ultra-low temperature resistance is stronger than opaque and weak gluten wheat, waxy wheat’s ability of Ultra-low temperature resistance is poor.4. According to the main seed vigor indicators and the changes of five enzyme activities of wheat seed stored at ultralow temperature, five wheat varieties (lines) seeds can find one suitable optimum moisture content at ultra-low temperature storage, Wanmai33is11.90%, Wanmai48is 9.99%, Yangmai158is9.90%, Zhengmai9023is12.23%, W1032(waxy wheat) is11.88%. Preliminary view was that wheat seeds were suitable for ultra-low temperature storage. The optimum moisture content of wheat seed stored at Ultralow temperature is from10%to12%, The optimum moisture content of keratin and Strong gluten wheat is12%, opaque and weak gluten wheat is10%, opaque and medium gluten waxy wheat is12%.