Cross breeding is the main way of crop breeding. At present, the grain and fruit we eat are basically hybrids. The offspring obtained by crossing several crops can have more advantages than their parents, such as high yield and high quality, strong disease resistance and stress resistance, which is heterosis. There are many natural hybrids in nature, and many fruit trees are natural hybrids. Both natural hybridization and artificial hybridization are based on hybridization compatibility, that is, they conform to the laws of nature. Therefore, hybrids are harmless.

With the development of scientific research, there are many hybrid fruits, such as citrus, which people like to eat. There used to be only a few varieties of citrus, but now there are dozens of varieties. For example, platinum sleeves, grapes, big cherries, ugly oranges, yellow watermelons, apple vegetables, lemon pomelo and Thai berries are all produced by hybridization, which has good taste, high water content and high sugar content, so the hybrid fruits are more popular.

What are the ways of tree breeding? What are the main breeding methods of apple trees? There are many ways to cultivate fruit trees. The main ways are:

1 introduction? That is, introducing new crops, new varieties or strains and genetic materials from other places or abroad for research.

2 seedlings? That is, the natural variation of fruit tree population propagated by seeds is selected to improve the genetic composition of the population or select excellent varieties from it.

③ Bud mutation breeding? That is, under the complex natural environment and long-term cultivation and management conditions, the meristem cells of its buds often produce mutant cells different from the mother cells, and the branches or individual plants produced by mutant buds are called bud mutation.

④ cross breeding? That is, hybrids are obtained through gamete combination between different genetic types, and new varieties are created through cultivation and selection. When using this method, it is the key to success to make clear the breeding objectives and correctly select parents. Hybridization can also be carried out between species or genera.

⑤ Multiple breeding? That is, fruit tree polyploid has the advantages of vigorous metabolism, huge organs, strong resistance and adaptability. Triple physical activity is low, often showing seedlessness or shrinking seeds. However, because the edible part of fruit is not seed, seedless is also an excellent quality.

⑥ Mutation breeding refers to radiation breeding with cobalt 60, gamma rays or neutron rays as irradiation sources and chemical mutation breeding with chemicals such as Akiyama Fairy essence as mutagens, which changes chromosome ploidy, rearranges chromosome structure or mutates genes by physical and chemical methods.