The Influence Of Tolerance Pumpkin At Low Temperature And Week Light

Pumpkin (Cucubita pepo L.) is one of the northern region winter greenhousevegetable species in China. In Pumpkin process, temperature and light is a necessarycondition for its growth and development. Especially in the production of greenhouse inwinter squash, it will be affected by different degree of low temperature and weak lightstress, seriously affecting the yield and quality of Pumpkin,reduced the income offarmers.The experiment with artificial climate box control temperature and illumination,weak light stress of different low temperature was studied in Pumpkin seedlingmorphology and physiological and biochemical characteristics, the influence of thesifting can identify Pumpkin the evaluation index of weak light resistance to lowtemperature, the results are as follows:The weak light and low temperature make Pumpkin seedlings hypocotyl lengthchange quantity is small, the second function of leaf area reduced the volume ofchanges and above ground dry fresh weight and underground part dry fresh weight bothdecreased, growth was significantly inhibition; At low temperature, low temperatureresistant weak light group Pumpkin and weak light resistance to low temperature ofPumpkin hypocotyl length, fresh weight and dry weight of aerial part of aerial partsignificant difference; Under the weak light, two groups of Pumpkin hypocotyl length,fresh weight of aerial part and a second function leaf area of significant difference;Under the weak light stress in low temperature stress, the form of two groups ofPumpkin index variation has a significant difference.As the degree of weak light stress increased at low temperature and duration,Pumpkin leaf free proline content in first increase then decrease, and the content ofsoluble protein continues to decline, root activity weakened gradually, photosyntheticpigment content varies with declining processing time; Among them, low temperatureresistant weak light group Pumpkin and not resistant to low temperature weak lightPumpkin proline content, soluble matter content of significant difference; Under theweak light, two groups of Pumpkin the chlorophyll content of the significant difference;Low temperature under the weak light, two groups of Pumpkin the root activity ofsignificant difference. Weak light in low temperature caused the Pumpkin seedlings SOD, CAT activitydecreased, a significant rise in POD activity, MDA content rose sharply, leading toPumpkin seedlings cell membrane injury; Among them, at low temperature, two groupsof Pumpkin significant differences in SOD activity and POD activity; Under the weaklight, two groups of Pumpkin the MDA content of the significant difference; In lowtemperature under the weak light, significant difference was found in two groups ofPumpkin CAT.In low temperature and weak light and low temperature weak light three kinds ofadverse circumstance, two groups of Pumpkin aerial parts of the hypocotyl length andfresh weight and dry weight of these three indicators were significant difference rate ofchange, so the three indexes can be used as a good low temperature resistance theappraisal index of weak light, in the low temperature under weak light stress under thenormal temperature to run with the change of the change of the difference is smaller, thetolerance is stronger at weak light and low temperature.