General Instructions:
- Copy the given assignment of practical in fair practical copy of biology.
- Make the use of black pen for heading and sub-headings and blue pen for writing other content.
- Work should be presentable.
- Make well labelled and proper diagram as provided in this assignment.
Spot No.10
Aim: To perform emasculation, bagging and tagging for controlled pollination.
Materials required: Ornamental plants bearing large bisexual flowers, forceps, small sharp scissors, alcohol, paper clips, tags, rubber bands, brush, and paper bags.
Theory: Plant breeding programs involve bringing under human control reproductive processes that lead to better seed and better fruit formation. For this controlled pollination is desirable using male and female parent having desired traits.
Emasculation is the process that can be easily brought under human control. For this the knowledge of flower structure, mechanism of pollination, fertilization and physiology of flowering is essential. In emasculation technique, the stamen are removed before anthesis to obtain female parent and pollen forms the desired male parent is transferred on to its stigma.
Procedure:
- Select a good variety of a plant
- Now, select a flower in bud condition where antheses has not occurred.
- Open the bud carefully and remove the stamen. Mark this as female parent plant.
- Cover the emasculated flower with a transparent plastic bag with minute pores in it to protect it from undesired pollen (Bagging).Tie the bag in place with a paper clip/string/thread.
- Now, bring into physical contact anthers of a desired male plant containing mature pollen grains with the stigmatic surface of emasculated female flower. Use forceps/brush if necessary to dust stigmatic surface with pollen.
- Again cover the pollinated flower again with the bag immediately, till seed setting is completed in the flower.
- After controlled pollination, a tag (label) should be fixed below the flower.
- The tag contain the name of the seed parent, the letter X (to signify a cross), the name of the pollen parent and the date on which the cross was effected.
Observetaion: After controlled pollination, the plant is kept undisturbed and under observation till seed settings and harvesting. This leads to the success of the experiment.
Result: By the process of controlled pollination, the female parent plant will produce seeds of the desired characteristic.
Precautions:
- A good variety of parent plant should be selected.
- Care should be taken while doing emasculation.
- After controlled pollination,, proper care of experimental plant should bed done till seed setting.
