(1) Here, parts of two plants are joined in such a way that they grow into one plant. In this method, part of the stem containing more than one bud (Scion) is joined onto a rooted plant called stock, is called grafting. Budding is also called bud grafting, in which only one bud is joined on the stock, e.g. Apple, Pear, Rose, etc.
(2) It is the phenomenon of the formation of the embryo(s) through the asexual reproduction method without the formation of gametes and the act of fertilization. Alternatively, it is unusual sexual reproduction where there is no meiosis and syngamy. The embryo develops in the ovule, and the ovule develops to form a seed. In apomixis, when a gametophyte organ or cell produces embryo like structure without fertilization, it is called apogamy. Similarly when a diploid sporophyte cell produces a diploid gametophyte without undergoing meiosis is called apospory, e.g. Orange, Mango.
(3) Polyembryony is a form of seed development in angiosperms where more than one embryo forms within a single seed. It leads to the germination of multiple seedlings from one seed and is classified as either true or false based on whether the embryos arise from the same or different embryo sacs. This condition can occur due to the development of additional embryos from various maternal and zygotic tissues within the ovule. In citrus fruits, for instance, adventive polyembryony occurs when an embryo develops directly from the diploid nucellar cells, while cleavage polyembryony involves the division of a zygote into multiple units, each developing into a separate embryo. This biological feature enhances plant survival rates and has significant applications in horticulture, particularly for preserving the genetic consistency of plant varieties.
(4)
- This term is coined by Noll (1902). It is the condition in which fruit is developed without the process of fertilization.
- It occurs naturally in some varieties of Pineapple, Banana, Papaya, etc.
- In these plants, it seems that the placental tissue in the unfertilized ovary produces auxin IAA (Indole-3 Acetic Acid) which is responsible for enlargement of ovary into fruit.
- The fruit resembles the normally produced fruit but it is seedless.