Research On The Rootstock Selection For Cucumber 'Nan Shui2' And Humidity Control Device During Healing Period

'Nan Shui 2' is a special mini-cucumber bred by lab of cucurbit genetics and germplasm enhancement for protected cultivation.It is very suitable for market promotion due to its excellent commodity value and appropriate for facility cultivation.However,susceptibility of 'Nan Shui 2' to Fusarium Wilt is insufficient.As a result,it is extremely urgent to select suitable rootstock to enhance cold resistance and disease resistance of 'Nan Shui 2'.The humidity during healing period of grafted seedlings was found very important to improve grafting success rate of tube grafting.In this experiment,Cucumis metuliferus,Bur gherkin,IL10-1,Cucurbita moschata and Cucurbita ficifolia were used as rootstocks for 'Nan Shui 2' when non-grafted cucumber 'Nan Shui 2' was used as a control.We investigated in the field after planting.At the same time,related growth and development indexes including the characteristics of flowering and fruiting were measured and compared between different grafted combinations are listed.The results showed that grafting could prolong the vegetative and fruiting period,and reduce the rate of fruit abortion and morbidity.Besides,stem diameter,number of stem nodes and leaf area were measured in different grafted cucumbers.'Nan Shui 2' showed the biggest increase of these indexes with the lowest increasing rate.Cucumber using Bur gherkin as stock exhibited the highest increasing rate compared to others.In addition,using Bur gherkin as stock could promote the early flowering and early fruiting as the grafting combination showed enhanced blooming date of the first female flower and collection time of fruits.The content of soluble sugar and Vc in cucumber leaves and fruits were significantly decreased in grafted cucumber using Cucurbita ficifolia,Cucumis metuliferus and IL10-1,Cucurbita moschata,Cucurbita ficifolia as stocks.On the contrary,using Bur gherkin as stock could significantly increase the content of soluble sugar and Vc.In summary,Bur gherkin was suitable for 'Nan Shui 2,cucumber as a rootstoke because of its good compatibility and trait improvement.To explore the appropriate relative humidity of the atmosphere during healing period of grafted seedlings,organic glass box cover with different hole diameters and numbers were used in the experiment.The result turned out that the appropriate relative humidity for grafted seedlings is not always the same during different healing periods.In our experiments,all three holes(16 holes,18 holes,24 holes)of box covers could be used 4 to 7 days after grafting.8 to 12 days after grafting,16 holes are available as bore diameter of the holes was 5.1 mm which on the the box covers.12 to 20 days after grafting,20 holes are available as bore diameter of the holes was 7.5 mm which on the the box covers.