Selection Of Muskmelon Hypoxia-resistant Rootstocks And Study On Physiological Characteristics Of Hypoxia Tolerance

Aiming at the problem of hypoxic stress becoming increasingly serious in soilless cultivation,the experiment used hypoxia-sensitive Xiyu-1 muskmelon(Cucumis melo L.var.raticulalus Naud)as scion,9 pumpkin (Cucurbita moschata L.)varieties(Huangjinteng,TianshenF₁,Xiaoquanwang, Guozhen-1,ZhuangshiF₁,Yongzhen-2,Shengzhen-1,Heqinzhen,Figleaf gourd),3 luffa(Luffa cylindrical L.Roem.)varieties(Guiguan-2,Local luffa,Sweet and fragrant),2 gourd(Lagenaria siceraria sttandl cv.)varieties (Northern and Southern),Short-body PuGua,ZaoqingF1 summer squash(Cucurbita pepo L.)and Jialiang solid,wax gourd(Benincasa hispida Cogn.)as rootstocks,to compare the compatibility and hypoxia tolerance of grafted muskmelons on different rootstocks and select hypoxic-tolerant stocks suit for muskmelon soilless culture;And two endurance rootstock cultivars to root-zone hypoxia stress were adopted to research the physiological characteristics.Finally,the feasibility of double-root grafting was elementarily explored in muskmelon soilless cultivation.The main results were as follows: 1,The growth and development of plant,yield and fruit quality were investigated.The results showed that:Huangjinteng,Yongzhen-2,ZhuangshiF₁, TianshenF₁,Heqinzhen,Shengzhen-1,Xiaoquanwang were best,followed by Guiguan-2,South hyacinth etc.,but North hyacinth,Shixin wax gourd, Aishen gourd etc.weren't suited for rootstock for Xiyu-1 muskmelon.2,Using Xiyu-1 as control,the hypoxia tolerance of 12 kinds of grafted seedlings was sed under hypoxia stress.The results showed that the growth and chlorophyll content of 12 grafted seedlings and self-rooteded seedling were subjected to different levels of restraint,the MDA content were enhanced.Different stocks had varying hypoxic-tolerant ability:the hypoxic tolerant of Guiguan-2 Luffa and Huangjinteng pumpkin etc.were the highest, TianshenF₁ pumpkin and Heqin pumpkin etc.were the secondary, Xiaoquanwang pumpkin and Nanfang Hyacinth etc.were the lowest.3,The physiological characteristics of hypoxic-tolerance was studied using Huangjinteng pumpkin and Guiguan-2 towel gourd as material.The results showed that:the malondialehyele(MDA)content and electrolytic leakage(%)in the roots and leaves of grafted seedlings were lower,the praline content and activity of antioxidant enzymes such as supreoxide dismutase(SOD),peroxidase(POD),catalase(CAT)in the roots and leaves of grafted seedlings were higher under hypoxia stress.There was a considerable difference of hypoxia tolerance between the two grafted muskmelon seedlings. In addition,the response to hypoxia stress of roots and leaves had some differences.4,Huangjinteng pumpkin,ZhuangshiF₁ pumpkin and Guiguan-2 towel gourd as rootstocks,Xiyu-1(CK)as scions and two grafting methods have been used to study the effects of two grafting methods on growth, development and fruit quality formation of grafted muskmelon in soilless cultivation.The results showed that the survival rate of grafting muskmelons had no significant difference between two grafting methods.The average fruit weight of Huangjinteng and ZhuangshiF₁ grafted seedlings were higher than self-rooted seedlings,the fruit shape and quality of 3 double-root grafted seedlings were similar with those in self-rooted seedlings,taste was improved.5,The rsults of grafting experimentation,analysis of fruits quality and study of hypoxia-tolerant mechanism indicated that Huangjinteng pumpkin was most suitable for muskmelon hypoxia-resistant rootstocks in muskmelon soilless cultivation.