Modes of reproduction and apomixis lecture- Plant breeding and genetics

Modes of reproduction and apomixis lecture

1. PRESENTATION ON PRINCIPLES OF PLANT BREEDING APB-5211 3(2+1) Topic: Modes of Reproduction and Apomixes Dr. Shweta Gupta (Genetics and Plant Breeding) College of Agriculture and Research station , Marra, Durg (C.G) WELCOME

2. Reproduction : is the development of new individuals (progeny) from their pre-existing ones. (parents) The manner in which they originate is called modes of reproduction. The vegetative parts of the plant are the roots, stem and leaves. The reproductive parts of the plant are the flowers. In plants there are two main types of reproduction. They are asexual reproduction and sexual reproduction.

3. 1.) Asexual reproduction : In asexual reproduction new plants produced without the help of seeds. 2 .) Sexual reproduction : In sexual reproduction new plants are produced from seeds. 1) Asexual reproduction :Asexual reproduction does not involve fusion of male and female gametes. New plant may develop from vegetative parts. Asexual reproduction are two types: A. Vegetative reproduction B. Apomixes

4. Vegetative reproduction – is also two types 1.Natural vegetative reproduction (a) Rhizome – Ginger,Turmeric ( Curcuma longa ) (b) Tuber - Potato, Banana (c) Corm – Arbi ( Colocasia esculenta ) (d) Bulb - Onions, Garlic 2. Artificial vegetative reproduction (a) Stem cutting -Sugarcane, grapes, roses (b) Root cuttings- Sweet potato, citrus and layering ,grafting and gootee

5. 2.) Sexual reproduction : Flowers are the reproductive parts of the plant. Stamen is the male reproductive part and pistil is the female reproductive part. Flowers which have only the stamen or only the pistil are called unisexual flowers. Eg :- Maize, Papaya, Cucumber etc. Flowers which have both the stamen and pistil are called bisexual flowers. Eg :- Rose, Mustard, Petunia etc. The stamen has a filament and anther. The anther contains pollen grains which contain the male gametes. The pistil has stigma, style and ovary. The ovary contains ovules which contain the female gamete or egg. In sexual reproduction the male and female gamete fuse together to form a zygote.

6. Male Gametophyte Female Gametophyte

7. Apomixis - In apomixes seed are formed but the embryo develop without fertilization. (without the sexual fusion) (a) Adventive embryony - Embryos develop directly from the vegetative cells of the ovule, nucellus, integument and chalaza and it does not involve production of embryo sac. Ex. Mango, Citrus, Orchids etc (b) Gamatophytic apomixes- Embryos develop without fertilization from the egg cell and other cells of embryo sac.

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