Effects Of LED Supplementary Lighting On Seedling Growth And Fruit Quality Of Oriental Melon(Cucumis Melo Var.Makuwa Makino)

The oriental melon(Cucumis melo var.makuwa Makino)belongs to the vegetables of enjoying light and it has a higher demand for light intensity and quality,however,in the greenhouse,the melon was in a weak light environment for a long time because of film aging,pollution and rainy weather,and it was extremely unfavorable to growth,development,yield and quality of melon.Therefore,We used oriental melon ’Yumeiren’ as the experimental materials to study effects of different light quality of LED and different light time on seedlings growth and fruit quality in oriental melon through LED supplementary lighting at seedling and fruiting stages.The main purpose is to provide the theoretical and practical guidance for cultivate strong seedlings and high-quality cultivation of oriental melon.The main results are as follows:1.The oriental melon ’Yumeiren’ was used as experimental material and the seedlings were light treated for two weeks at the three leaves stage.The growth indexes and photosynthetic indexes were measured under 5 kinds of light quality(red,blue,red and blue 3:1,6:1,8:1)treatments and compared to the treatment without supplementary lighting as control.The results showed that plant height of oriental melon seedling was maximum under the red light treatment,showed spindling,and followed by red and blue 6:1,8:1,3:1 and blue treatments.The stem diameter,leaf area and chlorophyll content were the largest under blue,red and blue 6:1,followed by the red and blue 8:1,3:1,and red treatments.The fresh,dry weight,seedling index and the net photosynthetic rate and concentration of intercellular CO2 of oriental melon seedlings were the highest under red and blue 6:1 treatment.Meanwhile,reached to maximum under blue light,red and blue 6:1 but there was no significant difference in chlorophyll a under different treatments.These results suggested that the LED light can promote the seedling growth of oriental melon and there are differences in different treatments,the oriental melon seedlings under the ratio of red and blue 6:1 light treatment had a better growth.2.The oriental melon was light treated at 10 days after anthesis,fruit appearance and quality index were tested under 3 kinds of light(red,blue,red and blue 6:1)treatments for 5,10,15 and 20 days,respectively,compared to the treatment without supplementary lighting as control.The results showed that oriental melon fruit size,fruit weight,soluble sugar,Vc and volatile component under the treatment of red and blue 6:1 were higher than red,blue light treatments and control at the same time in fruit,these results suggested that the LED light can promote the fruit quality of oriental melon,the ratio of red and blue 6:1 light treatment had a better effect in three treatments.3.The oriental melon was light treated at 10 days after anthesis,the melon fruit yield,soluble solids,soluble sugar,SS,SPS,LOX,ADH,AAT activity and gene expression were determined during fruit harvest under red and blue 6:1 LED light treatment for 1,2,3,and 4 weeks.The results showed that all of indexs were enhanced with increasing light time and tended to be stable in fill light 3 weeks.In addition to the activity of ADH had no significant difference at different time,other indexs were the highest in fill light 3 weeks.These results suggested that there are differences between the yield and quality of oriental melon fruit in different light time,fill light 3 weeks is the best.4.Through the analyses of relative gene expression of CmSS01,CmSPS01,CmLOXs,CmADHs,CmAATs in melon fruit under different lighting time by real time fluorescent quantitative PCR technique.The results showed that fruit CmSS01,CMSPS01,CmLOX07,CmLOX08,CmLOX09,CmLOX16,CmLOX18,CmAAT01,CmAAT02,CmAAT04 relative gene expression the highest under 3 weeks LED light treatment,there was no significant difference between CmLOX17 and CmAAT03 at different treatment time.The above results showed that LED light can enhancement to seeding growth,and improve the seedling index,fruit yield and quality of oriental melon.In a word,the red and blue 6:1 LED light is the best choice of oriental melon,and 3 weeks LED light treatment is appropriate in practicalproduction.