In the process of development and evolution, any plant has formed a close relationship. Camellia must also have affinity between scion and rootstock. Generally speaking, the closer the kinship, the stronger the affinity. When scions and rootstocks are combined, the nutrients supplied to each other are more suitable for each other's needs and are easily accepted by each other, and grafting is generally easy to survive. On the contrary, the scion and rootstock of distant camellia are quite different, and their affinity is weak, so it is generally difficult to survive after grafting. According to this truth, when grafting, the configuration of scions and rootstocks should choose related camellia with strong affinity, so that grafting is easy to survive. Generally, intraspecific grafting of camellia is easy to survive, such as camellia and camellia oleifera, tea plum, East China camellia, Yunnan Nanshan tea and so on. Grafting between Camellia is more difficult, especially among Theaceae.
The age and development stage of camellia oleifera also have great influence on scions and rootstocks. After grafting, the crown formed on the graft is developed from scion, and the root system is formed from rootstock. The two should be influenced each other. Generally speaking, the heredity of camellia in its infancy has not been fully demonstrated, it is not very stable, and it is easy to be influenced by external nutrition and mutate; On the contrary, the older the tree, the older the development stage, and the more stable the heredity of camellia, so it is not easily affected by the outside world. Therefore, in order to maintain the excellent characters of a camellia variety, it is necessary to collect scions from older branches at the development stage and graft them on young rootstocks, so that the varieties developed from scions can maintain the excellent characters of the original varieties. Grafting scions of Camellia oleifera should generally be cut from mature plants with strong growth and no pests and diseases. Although these branches may be 1 ~ 2 years old, they are in the older part of the development stage, with stable inheritance, which can maintain the excellent characteristics of the varieties and bloom ahead of time. The best rootstock is 2 ~ 3 years old seedlings. This rootstock has strong vitality, grows vigorously after grafting, and can maintain the characteristics of the parent tree. On the contrary, if we want to change the heritability of scions, we should choose scions from plants with small tree age and young development stage. Generally, when grafting breeding is carried out, it is hoped that scions will be influenced by rootstocks and produce new varieties with excellent characteristics of scions and rootstocks to meet the needs of breeding.
Selecting wild species as rootstock grafting cultivation varieties can play the role of fostering strengths and avoiding weaknesses. Cultivated varieties of Camellia, especially some rare varieties, are cultivated by people after long-term selection, so they have strong ornamental characteristics and are deeply loved by people. Cultivated varieties and valuable varieties are cultivated under superior conditions, which are tender, drought-tolerant, barren in soil and often worse than wild varieties in pest resistance. Because wild species live in the wild for a long time, they are generally adaptable and can grow and develop under harsh natural conditions. We use grafting technology to graft the scions of cultivated varieties and rare varieties to the rootstocks of wild species, which can achieve good results. Therefore, many camellia producers like to use wild varieties with winter tolerance or wild characteristics, such as Jin Xin Dahong and Jinpan Litchi, as rootstocks. Generally speaking, rootstocks with thick growth potential have long branch pitch and thick leaves; Rootstocks with uniform growth potential and expansion have short spacing between branches and nodes and little change in leaves.
The configuration of rootstock and scion is the key to the success or failure of grafting, which must be considered comprehensively according to the characteristics of rootstock and scion, the purpose of grafting and the influence after grafting.