Effects Of Cerium On Cold Resistance Of Cucumber Seedling

Cucumber, originated from subtropical zone, is sensitive to low temperature. The coldsusceptivity of cucumnber is the main limiting factor of growth, therefore, how to improve thechilling tolerance is the research emphasis of recently cucumber cultivation. The rare-earthelements, especially cerium, lanthanum and neodymium, have the promoter action on growthand the nutritive element's absorption and using, in addition, can effectively improve theenzyme activities which have definitely physiological effects, as well as adversity stress.This experiment used different winter hardiness varieties of cucumber, "jinchun4" andluosika15", as materials, and set up different concentrations sprouting of cerium to research theeffects of cerium on the cold resistance of cucumber by analyzing germination situation ofcucumber seeds under different low temperatures, the cold indexes of cucumber seedling, andthe changes of physiological-biochemical indexes, the result showed,1 The pregermination experiment showed that, 600mg/L CeCl₃ could obviously limitgermination of cucumber seeds, in contrast, 25mg/L, 75mg/L, 150mg/L and 300mg/L couldeffectively improve germination, and the effect of 150mg/L and 300mg/L were better than0.0075%. The promote action of cerium on germination had some range by the experimentwhich seeds couldn't germinate under 55℃2 The low temperature stress degree could effectively decrease after 150mg/L and300mg/L CeCl₃ sprouting, so the suitable concentrations of CeCl₃ to seedling were 150mg/Land 300mg/L.3 The synthesis of chlorophyll was limited and the contents were decreased under lowtemperature stress, and the chlorophyll contents could increase after suitable concentrations ofCeCl₃ treating compared to rinsing contrast, as well as the Pro contents. In addition, theincrease extent of the relative EC and MDA contents could effectively lower after suitableconcentrations of CeCl₃ treating under low temperature stress compared to rinsing contrast.However, the decrease extent of POD and CAT could effectively lower after suitableconcentrations of CeCl₃ treating under low temperature stress.