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Pollen Germination Experiment for Class 12

STUDY OF RATES OF POLLEN GERMINATION OF VARIOUS SPECIES IN SUGAR AND BORON SOLUTION

Introduction

 

Pollen grains or microspores are the male gametophyte of angiosperms. The process of transfer of pollen grains from anther to the stigma of a flower is called pollination. Pollen grains germinate after reaching on the stigma. A pollen grain has usually two cells, generative cells and vegetative cell at the time of pollination. A mature pollen grain has 2 layers outer thick exine and inner thin intine. Here and there in the exine small thin areas are present, they are called germ pores. During pollen germination a pollen tube grows out from the pollen grain through a germ pore. The generative cell move down to the pollen tube and divide into two male gametes. The pollen tube enters the embryosac and releases the male gametes to ensure fertilisation. The rate of pollen germination differs in different plant species.

 

Materials and Methods

 

Flowers of different plants, cavity slides, sucrose, boric acid, distilled water, beaker, micro-scopes etc were collected.

 

A nutrient solution was prepared by dissolving 1 gm of sucrose in 100 ml distilled water. Five clean cavity slides were taken and a few drops of nutrient solution was put in the cavity of each slides. In this nutrient solution the pollen grains from different flowers were dusted. Similarly another nutrient medium was prepared by dissolving 1 gm of boric acid in 100ml of distilled water and the experiment was repeated with the pollen grains of flowers of different plants.

 

Observation and Results

 

Observe each slide containing sucrose solution one by one under five different microscopes after 5 minutes and after one minute each. Similarly observe each slide containing boric acid solution one by one under five different microscopes. Record the observations in the tabular column given below.

 

Rates of pollen germination of different species of plants in sucrose solution


Rates of pollen germination of different species of plants in boric acid solution


Discussions and Conclusions

 

The viable pollen grains germinate in both the nutrient solutions. But the germination percentage varies in boric acid solution and sucrose solution. This also depends upon the species variation and time factor.

 

References

 

Give a list of books and other reading materials you have referred for the present project work.

 

Viva Questions and Answers

 

1. What are viable pollen grains?


The pollen grains which are able to germinate and produce male gametes are called viable pollen grains.

 

2. Why a nutrient solution is required for pollen germination?


Because nutrients are essential for the growth of pollen tube.

 

3. Where do pollen grains germinate?


Pollen grains germinate on the stigma. 

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