A crossing or mating of two plants of dissimilar genotype is
known as hybridization. The seeds as well as progeny resulting from the
hybridization are known as HYBRID or F1. The main purpose of
hybridization is to create variation in plants by transferring one or more
characters into a single variety from other varieties.
TYPES OF HYBRIDIZARION:
a) Intra-varietal hybridization: The crosses are made between plants of same variety.
b) Intraspecific hybridization: The crosses are made between plants of different varieties.
STEPS FOR HYBRIDIZATION:
1)Selection of parentsIt is mainly depends upon the objective of the breeding program.
2)Evaluation of parentsIt is essential for inducing homozygosis for eliminating the undesirable characters.
3)EmasculationIt can be defined as the removal of stamens or anthers or the killing of the pollen grains of the flowers without affecting in anyway the female reproductive organ. Emasculation is not required in unisexual plants but it is essential in bisexual or self-pollinated plants.
There are various methods of emasculation they are,
a) Hand emasculation
b) Hot water treatment
c) Cold water treatment
d) Alcohol treatment
e) Suction method
f) Male Sterility or Self-incompatibility method
g) Chemical Gametocytes
4) BaggingThe emasculated flowers should be kept properly covered so that no untoward crosspollination takes place. This is done by closing the flowers in oil paper or polythene bags.
5)TaggingThe tags are attached to the base of flowers or inflorescence with the help of thread. The information on the tags are represented by;
1.Number referring to the field record.
2. Date of emasculation.
3. Date of crossing.
4.Name of the female and male parent.
6) CrossingIt can be defined as the artificial cross-pollination between the genetically unlike plants.
7) Harvesting and storing the F1 seedsAfter the proper growth of the crossed plants they are harvested, completely dried and stored.
8)Rising the F1 generationThe stored seeds are sown separately to rise the F1 generation.
c) Interspecific hybridization: The crosses are made between different species of the same genus.
OBJECTIVES OF HYBRIDATION:1.To combine the desired character into a single individual.
2.To exploit and utilize hybrid varieties.
3,To create variable population artificially.
MERITS:1.Hybrid plants are usually more vigorous and faster growth.
2.Hybrid plants are less susceptible to problematic growing conditions.
3.These plant types are also more resistant to many diseases and afflictions.
1.Seed is to be replaced every few years.
2.Seed certification poses difficulties.
3.It is less attractive, less uniform and costly method.