Study On The Screen Of Rootstocks And Graft Affinity Mechanism For Cucumber

Cucumber (Cucumis sativus L. ) is a important gourd vegetable, the technology of graft breeding of cucumber is widely used to practical production. The rootstocks of cucumber is not enough, study of the mechanisms of affinity on cucumber almost rest on the aspects of physiology and biochemistry. This experiment used JinChun-4 as scion and pumpkin, bottle gourd as rootstock, the grafted seedlings of JinChun-4/fig-leaf-gourd and self-rooted cucumber seedlings as CK, selected rootstock with good affinity. Microstructure measurement and mRNA differential expression of healing parts at different stages of the grafted seedlings of self-grafteded Chinese pumpkin 57, self-grafted JinChun-4 and JinChun-4/fig-leaf-gourd were used to study the mechanism of graft affinity from the levels of cells and molecular. This experiment used plant characters and tissue sections of JinChun-4/Chinese pumpkin 57, JinChun-4/bottle gourd Hua No.3 and JinChun-4/fig-leaf-gourd, studied the mechanisms of symbiotic affinity from individual and cell levels. The main results were as follows:1. Rootstock screening, the survival rate of grafting was statisticsed with JinChun-4 as scion and pumpkin(Chinese pumpkin strains 45,57,78 and 80), bottle gourd (bottle gourd Hua No.3) as rootstock, the grafted Seedlings of JinChun-4/fig-leaf-gourd and self-rooted cucumber seedlings as CK, the fifth day after planting characters of grafted cucumber seedlings were surveyed at the first time, then every five days surveyed once, yield were investigated and agronomic characters were recorded, quality of merchantable cucumber fruit were measured. The grafted seedlings of JinChun-4/fig-leaf-gourd and self-rooted cucumber seedlings were control. The results showed that, surviving rate of different grafted plants is above 90%, yield of bottle gourd Hua No.3 was significant higher fig-leaf-gourd, Chinese pumpkin strains and self-rooted cucumber. The twenty-fifth day after planting, fig-leaf-gourd, bottle gourd Hua No.3 and self-rooted cucumber had no obvious differences in scion widen, stem widen, main vine height, leaf number, leaf length and wide leaf blade, but had significant differences with Chinese pumpkin strains. The node of 1st female flower of bottle gourd Hua No.3 was significant lower than fig-leaf-gourd and Chinese pumpkin strains, but was no obvious difference with self-rooted cucumber. Bottle gourd Hua No.3 has the lowest node of root-frut among stocks. Grafting had no obvious effects on fruit quality. Fig-leaf-gourd, Bottle gourd Hua No.3 and self-rooted cucumber can be classified into one group by cluster analysis of characters. These results indicated that bottle gourd Hua No.3 had no obvious effects on the growth of cucumber, but significant improved the yield of cucumber, bottle gourd Hua No.3 were good stocks of cucumber.2. The study of understanding the mechanism of grafting compatibility was in this way: Microstructure measurement and mRNA differential expression of healing parts at different stages of the grafted seedlings of self-grafted Chinese pumpkin 57, self-grafted JinChun-4 and JinChun-4/fig-leaf-gourd were used to study the graft affinity. The results showed that healing speed of the grafted Seedlings of Self-grafted JinChun-4 was faster than others. The result of cDNA-AFLP of pumpkin grafting seedling which rootstock was itself at different phase showed the specific bands would appear in samples after grafting 6 days. Chinese pumpkin 57, bottle gourd Hua No.3 and fig-leaf-gourd as rootstock, JinChun-4 as scion were used to research symbiotic affinity. After planting, characters of grafting seeding were investigated at different phases, the effects of xylem sap about cucumber growth was studied, and the healing parts of grafting seeding were observed in anatomical morphology. The results showed that the effects of different rootstocks were different. The trend of scion growth was fig-leaf-gourd, bottle gourd Hua No.3 as rootstock was better than Chinese pumpkin 57. The xylem sap of bottle gourd No.3 as rootstock was the best one to promote grafting seedling of cucumber to grow significantly. The results of anatomical morphology of the healed sections of grafting seeding showed vascular bundle of grafting seeding which bottle gourd Hua No.3 was as rootstock was the best developed than others. These results indicated that grafted combination with good affinity has developed vascular and produces hormones which promoted the growth of plants.This research screened a good rootstock of cucumber named bottle gourd Hua No.3 which can be used to graft of cucumber, studied the mechanism of affinity on graft which can provide theoretical basis for the study of the mechanism of affinity.