Question

Deffrentiate between halogamy and autogamy​

Answer 1

Answer:

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Crop Improvement :: Mode of Pollination

The process by which pollen grains are transferred from anthers to stigma is referred as pollination. Pollination is of two types: viz. 1) Autogamy or self pollination and 2) Allogamy or cross pollination.

I. Autogamy

Transfer of pollen grains from the anther to the stigma of same flower is known as autogamy or self pollination. Autogamy is the closest form of inbreeding. Autogamy leads to homozygosity. Such species develop homozygous balance and do not exhibit significant inbreeding depression.

Mechanism promoting self-pollination

1. Bisexuality. Presence of male and female organs in the same flower is known as bisexuality. The presence of bisexual flowers is a must for self pollination. All the self pollinated plants have hermaphrodite flowers.

2. Homogamy. Maturation of anthers and stigma of a flower at the same time is called homogamy. As a rule, homogamy is essential for self-pollination.

3. Cleistogamy. When pollination and fertilization occur in unopened flower bud, it is known as cleistogamy. It ensures self pollination and prevents cross pollination. Cleistogamy has been reported in some varieties of wheat, barley, oats and several other grass species.

4. Chasmogamy. Opening of flowers only after the completion of pollination is known as chasmogamy. This also promotes self pollination and is found in crops like wheat, barley, rice and oats.

5. Position of Anthers. In some species, stigmas are surrounded by anthers in such a way that self pollination is ensured. Such situation is found in tomato and brinjal. In some legumes, the stamens and stigma are enclosed by the petals in such a way that self pollination is ensured. Examples are greengram, blackgram, soybean, chickpea and pea.

II. Allogamy

Transfer of pollen grains from the anther of one plant to the stigma of another plant is called allogamy or cross pollination. This is the common form of out-breeding. Allogamy leads to heterozygosity. Such species develop heterozygous balance and exhibit significant inbreeding depression on selfing.

Explanation:

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Answer 2

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the word autogamy mean self fertilization. this is a special type of self pollination in which an intersexual or top flower is pollinated through its own pollen. Autogamy is only possible when anther and stigma are close to each other and which has synchrony in pollen release and stigma respectively. It is frequently meet in unicellular organisms such as protozoan, protist.

autogamy in plant :- the plant which is capable to fertilize themselves rather than hybridize with another plants.

Autogamy occurs by three method:-

Namely-homogamy

Cliestogamy

Bud pollination