At present, many cultivated flower varieties are genetically unstable and cannot be propagated by sowing, while some varieties are difficult to take root or have stunted cuttings by cutting propagation. In this case, grafting propagation is usually used.
In most cases, grafted seedlings blossom and bear fruit earlier than sown seedlings, which is beneficial to the popularization of new varieties and shortens the breeding cycle. In addition, the plant type can be adjusted by selecting the rootstock type to enhance the adaptability to the environment.
(1) grafting
Cut 1 bud or several buds of annual branches or new branches of the same year as scions for grafting.
(1) cutting
Widely used in all kinds of woody flowers, it is the main method and basic technology of grafting.
Cut the scion. The cutter cuts from 1 ~ 3cm below the back of the lowest bud of the cut scion, cuts into the xylem 1/3, and then cuts parallel to the branches, not too deep, so as not to hurt the pith. The plane should be smooth. Then cut it from the other side of the same end and cut it into an acute angle of about 45. The cut scion has 1 ~ 2 buds.
Cutting of rootstock. Cut off the upper part of the rootstock stem horizontally from 4 ~ 8 cm above the pot surface with a branch scissors, and smooth the incision of the rootstock with a cutting knife. Select the smooth and flat side of the rootstock, obliquely cut a knife on the upper part of the cross section to expose the cambium, aim at the inside of the cambium, and cut a few centimeters vertically downward with a cutter. This part should be straight to avoid splitting.
Combination of scion and rootstock. See clearly the position of cambium on the incision of scion and rootstock, insert scion into rootstock, and make the cambium of scion and rootstock align and contact closely. If the thickness of rootstock and scion is different, one side of cambium must be well bonded. If you look from the side, there is a gap at the junction of the two, because the rootstock or scion has been cut unevenly and must be cut again.
The binding of the interface. The binding must be careful, and it is required not to touch the position of the scion, not to damage the tissue, and to bind firmly. The use of plastic film strips is not only convenient for operation, but also can prevent moisture from evaporating from the wound. Generally, species that are easy to survive only need to tie the interface. For varieties that are difficult to survive, especially in dry seasons or dry areas, all cuts and scions must be wrapped with plastic strips except for empty sprouting eyes.
Post-grafting management. In order to promote the healing of transplanted wounds, it is necessary to pay attention to properly increasing the temperature and humidity of the local environment. Grafted seedlings can be covered with plastic film, or plastic bags can be placed at the interface.
② Green branch grafting
This method is widely used in potted flowers. The grafting method is basically the same as the splitting method, except that the rootstock and scion are relatively green materials. Green branch grafting is mostly carried out in the vigorous growth period of flowers and trees. The earlier the time, the better the growth and maturity of grafted seedlings.
When grafting, first select the rootstock, leave 2 to several leaves at the base, remove the upper part with branch scissors, and cut the mouth smoothly. Remove the buds between the axils of each leaf and cut vertically from the center of the cutting part with a blade. The length of the incision is determined by the thickness of the seedling. The thickness is longer or shorter, generally 1.5 ~ 2.5 cm. Scions are cut into wedges, and both sides are required to be straight and smooth. When inserting the rootstock, the strata should be aligned. Bind with plastic strips. It is best to carry out green grafting in a small plastic shed (made of small wooden boxes), and then pay attention to removing the tillers sprouting in the leaf axils or other parts of the rootstock leaves. Green branches generally grow rapidly after survival, so attention should be paid to loosening the interface in time.
(2) bud grafting
Bud grafting is to cut off the lateral buds of excellent plant varieties as scions, with little wood or without xylem, peel off the skin incision of rootstocks and embed the buds as scions. This method is simpler than grafting technology, saves scions and is suitable for large-scale production and application.
Bud grafting is usually carried out in the vigorous growth period of plants. At this time, the sap flows, the bark is easy to peel off, and the operation is very convenient. It's usually July and August in the north, but there are differences among all kinds of flowers.
There are several methods of bud grafting, the most commonly used is "D" type bud grafting. First, select a smooth part at the base of the rootstock, cut a D-shaped incision with a bud grafting knife, and gently peel off the bark. Then, cut off the leaves of the scion branches, leaving the petiole. Take the bud with bud as the center, cut off a shield-shaped bud with the epidermis of 1.5 ~ 2 cm. After cutting, gently remove the xylem by hand, and embed the peeled bud into the rootstock. The bud piece must be close to the xylem of the rootstock, and the joint should be tied tightly with plastic film strips, only the bud point and petiole of the scion are exposed.
After 3 ~ 5 days' inspection, the scion did not shrink or the petiole fell off when touched, indicating that it survived, otherwise it could be replanted. After the sap of deciduous trees flows out in the next spring, 4 ~ 6 cm is reserved from the joint, and the upper part of the rootstock is cut off to make the scion germinate quickly. Evergreen plants can cut off the upper part of the rhizome as long as the buds survive.
(3) Docking
Grafting efficiency is relatively low, and the dosage of scion is relatively large, but because scion and rootstock are rooted plants, the survival rate is relatively high. It is often used for flowers that are difficult to reproduce by other methods.
First, plant the rootstock in a small flowerpot or other container. After grafting, hang the rootstock on the scion-picking mother plant. Select edges with similar thickness and smooth branches, and cut off 1/3 ~ 1/2 thick branches. The section is 3 ~ 5cm long and smooth. Align the arches on both sides and tie them tightly with plastic tape. When the interface between the two plants heals and grows firmly, the branches of the scion mother plant at the lower part of the interface are cut off, and the upper part of the rootstock is cut off to become a new independent seedling.