Breeding Methods in Asexually Propagated Crop
Crops which are propagated asexually or by vegetative means are known as asexually propagated or vegetatively propagated or clonal crops. There are some agricultural (Sugarcane, Potato, Sweet Potato, etc) and horticultural (Banana, mango, citrus, pears, peaches, litchi, etc) crops that propagates by asexual means. The main reasons of asexual reproduction are
1) Reduced flowering and seed set,
2) Non flowering in many cases.
3) To avoid inbreeding depression in certain crops and
4) Apomixis in some species.
Asexual reproduction produces the progeny, which are exactly identical to their parent in genotype, because the progeny is derived from the vegetative cells through mitosis. Therefore, the main advantage of asexually reproduction is that it preserves the genotype of an individual indefinitely.
Characteristics of Asexually Propagated Crops:
1. Most of these plants are perennial and annual. E.g Sugarcane, potato, sweet potato.
2. Many of them shows reduced flowering and seed set and many varieties do not flower at all.
3. They are invariably cross-pollinated.
4. They are nightly heterozygous and show severe inbreeding depression.
5. Many species are interspecific hybrid. E.g Banana, sugarcane.
6. Many species shows wider adaptation.
7. These crop consist of a large number of clones. i. e. progeny derived from single plat through asexual reproduction.