selfing and crossing techniques in cotton described

1. SELFING AND CROSSING
TECHNIQUES IN COTTON
Cotton is an often cross pollinated crop.
75% selfing and 25% crossing.
First flower to open is on the lower side
& near the main axis, the succession
between centrifugal & acropetal.
Anthesis occurs between 7-10 a.m.
although there is great variation in
flowering time.

2. EQUIPMENT REQUIRED
Forceps
Surgical blade
Surgical cotton
Camel hair brush
Petri dish
Thread
Soda straw tube
Butter paper bag
Tag
Lead pencil

3. SELFING
Methods
Tie the unopened floral bud with a thread
Cover the unopened floral bud with a butter paper bag
Labelling
Tag the selfed plants showing the name of variety &
your signature. Write with lead pencil so that it may not
be washed out by rains etc.

4. CROSSIN
G
Emasculation:
1. In the evening, select desirable floral bud. Cut the corolla by giving
an incision with a surgical blade near the basal line.
2. Remove the stamens with the help of pointed needle.
3. Slide the soda straw on the pistil after emasculation.
4. Plug the open end of straw with surgical cotton or cover the plant
with butter paper bag.
Pollination:
1. In the evening, bag the unopened desired male bud before
dehiscence.
2. Next morning, Collect the pollen grains from desired male flower in
a petri dish.
3. With the help of camel hair brush, Dust the pollen grains on the
stigma of female flower.

5. CROSSING
Labelling:
Tag the plants showing the name of variety, Date of pollination &
your signature. Write the female parent first. Write with lead pencil
so that it may not be washed out by rains etc.