The Effect On Physiology And Fruit Quality And Relative Expression Of Gene That Control The Biosynthetic To Cucurbitacin C Under Different Water Treatments

Cucumber is an important agricultural cash crop.The fruit of cucumber contains very rich nutrients and has a very high value to human body.However,in the agricultural production,the growth of cucumber and the fruit of cucumber are always affected by different cultivation environment.And it will result in bio-synthetic to Cucurbitacin C that the main ingredient of bitter substance in cucumber。It will have a further impact on the loss of economic.The elements of those environment mainly include temperature,illumination,nutrient,water etc.In this experiment,two kinds of cucumber varieties Zhongnong 16 and Huangshan old cucumber were selected.The seed sowing in the plug.The seeding be planted in the flower pot,when the seed grow to having four leaves.These pots be managed consolidatedly to provide the basis for further pot experiments.And it uses the potting test.Cucumber will be planted in the flower pot and be managed by same way before flowering period.When these cucumbers grow to flowering period and have a root melon,we set different treatments to these cucumber that contain 1.8L/2d,1.5L/2d,1.2L/2d,0.9L/2d,0.6L/2d and 0.3L/2d.1.8L/2d expresses watering 1.8L in two days and the rest can be done in the same manner.In the process of processing we test the antioxidant enzyme activities and MDA about cucumber leaves under different treatments in fifth and fifteenth days.When fruit get ripe,we test the the yield of cucumber fruit,water content,soluble sugar,vitamin C,soluble protein,organic acid and Cucurbitacin C.We also identified genetic of cucumber plant about bitter taste type by PCR.We test the relative expression of Csa680 by RT-PCR.To research the relationship with the antioxidant enzyme activities,yield of fruit,quality of fruit and the relative expression of gene that control the bio-synthetic to Cucurbitacin C under different water treatments.The preliminary results of this article indicate: the results of antioxidant enzyme activities of cucumber leaves will be increased with the decrease of water content in early processing.Treatments of 0.6L/2d and 0.3L/2d will appear that the activity of antioxidant enzymes be decreased.The MDA will be increased with the order from to 1.8L/2d to 0.3L/2d.With the reduction of water,cucumber production is affected to some extent.Water content of fruit will be decreased with order from to 1.8L/2d to 0.3L/2d.Soluble sugar、vitamin C、soluble protein organic acid will be increased with order from to 1.8L/2d to 0.3L/2d.We cannot detect the Cucurbitacin C in variety of Zhongnong 16 under all water treatments.We can detect the Cucurbitacin C in variety of Huangshan old cucumber and the content of it is increased with the decrease of water treatments.The result of PCR indicates that the variety of Zhongnong 16 is the type of no bitterness and the variety of Huangshan old cucumber is the type of bitterness.The relative expression of Csa680 is Significantly higher than the contrast and it is increased with the decrease of water treatments to some extent.We get the preliminary conclusion: the initial water shortages will increase the antioxidant enzyme activity of cucumber leaves in the flowering period and will decrease with the time of water shortages be longer.The yield of cucumber fruit will be decreased with the loss of water and the quality of it will be increased to some extent.With the fruit whether have the cucurbitacin C,we can classify the cucumber to two types.The non-bitterness type will not detect cucurbitacin C under all water treatments.And the bitterness type will be detected the cucurbitacin C when the plant loss of the water and the content of it will be increased with the deep level of loss water.The relative expression of gene that control the bio-synthetic route to cucurbitacin C will be increased with the loss water of cucumber plants.