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Home Biomedical Engineering Biology Class 12 Controlled pollination - emasculation, tagging and bagging
Biology Class 12 Lab Experiments

Controlled pollination - emasculation, tagging and bagging



Aim: Controlled pollination - emasculation, tagging and bagging

Theory:

1. Plant breeding is a science of changing and improving the heredity of plant ans production of new varieties which are far better than original type.

2. Hybridization is a method by which improved varieties of economical important plants/crops are produced by crossing two or more genetically different plants.

A. Emasculation

Material / Apparatus Required: forceps or scissors method of emasculation.

Comment

i. This method is employed in the crops having flower sufficiently large size.

ii. The instrument used in this method includes pocket lens, forceps, needle, scissors, scalpel, hair brush, etc.

iii. In this process anther are removed from flowers before their maturation.

iv. The anther are cut with the help of sterilized forceps's or scissors.

Material / Apparatus Required: Hot or cold water and alcohol emasculation

Comment

i. This method of emasculation is employed the crop having small flowers like paddy, sorghum, etc.

ii. In this method the penicles (clusters of flowers are dipped in hot water (44 - 45°C) for 1 -10 minutes to kill the anthers.

iii. In the same way emasculation is done with cold water or alcohol.

B. Tagging and Bagging

Material / Apparatus Required: Bagging, tagging and labelling.

Comment

i. After emasculation, the flower is covered with small bags to prevent pollination with undesired pollen grains.

ii. These bags are made up of polyethene, paper, muslin cloth or parchment paper.

iii. The bags are punctured or made perforation so as to provide aeration to the flowers.

iv. The flower of male parents are also protected in bags to prevent mixing of their pollen grains with foreign pollens.

v. After dusting of the desired pollen grains on the emasculated flowers, the bags are re-tagged.

vi. A label of paper is tagged on the plant which display the date of emasculation, crossing and brief account of the parent.