selfing and crossing in maize

1. Demonstration of Selfing and
Crossing Techniques in Maize
(Zea mays L.)

2. QUICK FACTS
• Maize is a naturally cross pollinated crop.
• Maize is a monoecious plant.
• Staminate flowers are produced on the
tassel
• Pistillate flowers are produced on the stalk
• Pollen shadding starts before the appearance
of silks and continues for many days.
• Pollen may remain viable for 18-24 hours.

3. Breeders Kit
The equipment required for selfing and
crossing consist of following things:
A pair of scissors, Camel hair brush,
Kraft paper bag (14” × 11”)
Butter paper bag (7” × 3”)
Petri dish, Forceps,
Pencil, Tags and
Metylated spirit.

4. Selfing Procedure
1. Select the desirable plant in which the ear
has not produced the silks and the tassel
also immature.
2. Cover the tassel of the plant with kraft
paper bag.
3. Cover the ear shoot with butter paper bag
to avoid cross pollination.
4. Daily visit the plant for emergence of silks
on the ear.

9. 5. When the silks appear, collect the pollen
grains by shaking the tassel of the same plant
which was covered by kraft paper bag.
6. Place the pollen grains in petri dish.
7. Remove the butter paper bag from they ear
shoot of the plant and dust the pollen grains
with the camel hair brush on the silks of the
ear shoot.
8. Again cover the ear shoot with its respective
bag after pollination.

14. Important hints
9. Pollinate each ear shoot for 4 to 5 times to
ensure good seed setting.
10. If silks grow longer during pollination
days, cut them down to a 1” length with
scissors to facilitate easy pollination.
11. Leave the bag on the ear shoot till seed
sitting, to avoid foreign contamination.
12 Sterilize your instruments and hands with
methylated spirit before moving to the other
pollinations.

15. Long silks cut them with scissors

16. Tagging
Tag the selfed plant showing :
1. Date of pollination
2. Name of variety
3. Your signature

17. Un-pollinated
Pollination complete

18. Crossing in maize
1. If it is desired to make a cross in maize then
we require two varieties.
2. Suppose the variety treated as female is A
and the other whose pollen will be used is B
3. In variety A select a desirable plant in
which silks have not appeared and detassel
that plant to avoid self pollination.
4. In variety B select a desirable plant in
which the tassel immature and cover it with
kraft paper bag (14” × 11”)

19. 5. Daily visit the plant for emergence of silks
on the ear.
6. When the silks appear on plant A, collect
the pollen grains by shaking the tassel
plant B, which was covered by kraft paper
bag.Place the pollen grains in petri dish.
7. Remove the butter paper bag from the ear
shoot of the plant A and dust the pollen
grains with the camel hair brush on the
silks of the ear shoot.
8. Again cover the ear shoot with its
respective bag after pollination