Determination of Model of Sexual Reproduction The mode of sexual reproduction,i.e.,whether a crop is self-pollinated or cross-pollinated is reasonably well known for agricultural species.However,if it is not known in respect of a new crop species it can be easily determined.The various steps involved in determination are: 1)Examination of floral structure:The presence of unisexual flowers,dichogamy or other mechanisms(conditions)would indicate the likelihood of cross-pollination. 2)Seedset in isolated single plants:Grow single plants in isolation and observe whether seeds are produced or not. a)If no seed are produced,this is a certain indication that the crop species in question is cross-pollinated. b)If seeds are produced,then it is necessary to grow the selfed seed.Self-pollinated crops do not show inbreeding depression or adverse effects.On the contrary,in cross-pollinated crops the adverse effect of inbreeding is noticeable to varying degrees. 3)Extent of natural outcrossing:This is determined by interplanting with strains carrying a recessive marker gene.Seeda are harvested from the recessive type and the amount of natural outcrossing is calculated from the proportion of recessive and dominant progeny. 2.Asexual Reproduction Asexual reproduction means reproduction through vegetative parts of the plant,such as,buds(roses),bulbs(tulips),tubers(potato),stems(sugar-cane),or other parts,that are utilized to produce new individuals.In addition to these,there are types of asexual reproduction induced under the term apomixes which we shall detail below. Apomixis Apomixes is the substitution of a sexual process with an asexual process.All forms of asexual reproduction in higher plants that replace or act as substitutes for sexual reproduction are known as apomixes. Types of Apomixis 1.Agamospermy In this type of apomixes sexual organs or related parts take part but the seeds are formed asexually without the union of male and female gametes.This is due to modification of the normal meiotic and fertilization processes.Agamospermy is divided into three main groups. a)Gametophytic apomixes b)Adventitious embryony(adventive embryony,sporophytic embryony) c)Non-recurrent apomixes 2.Vegetative apomixes 99 Determination of Model of Sexual Reproduction The mode of sexual reproduction, i.e., whether a crop is self-pollinated or cross-pollinated is reasonably well known for agricultural species. However, if it is not known in respect of a new crop species it can be easily determined. The various steps involved in determination are: 1) Examination of floral structure: The presence of unisexual flowers, dichogamy or other mechanisms (conditions) would indicate the likelihood of cross-pollination. 2) Seedset in isolated single plants: Grow single plants in isolation and observe whether seeds are produced or not. a) If no seed are produced, this is a certain indication that the crop species in question is cross-pollinated. b) If seeds are produced, then it is necessary to grow the selfed seed. Self-pollinated crops do not show inbreeding depression or adverse effects. On the contrary, in cross-pollinated crops the adverse effect of inbreeding is noticeable to varying degrees. 3) Extent of natural outcrossing: This is determined by interplanting with strains carrying a recessive marker gene. Seeda are harvested from the recessive type and the amount of natural outcrossing is calculated from the proportion of recessive and dominant progeny. 2. Asexual Reproduction Asexual reproduction means reproduction through vegetative parts of the plant, such as, buds(roses), bulbs(tulips),tubers(potato),stems(sugar-cane), or other parts, that are utilized to produce new individuals. In addition to these, there are types of asexual reproduction induced under the term apomixes which we shall detail below. Apomixis Apomixes is the substitution of a sexual process with an asexual process. All forms of asexual reproduction in higher plants that replace or act as substitutes for sexual reproduction are known as apomixes. Types of Apomixis 1. Agamospermy In this type of apomixes sexual organs or related parts take part but the seeds are formed asexually without the union of male and female gametes. This is due to modification of the normal meiotic and fertilization processes. Agamospermy is divided into three main groups. a) Gametophytic apomixes b) Adventitious embryony (adventive embryony, sporophytic embryony) c) Non-recurrent apomixes 2. Vegetative apomixes