Question

write a short note on artificial hybridization​

Answer 1

Answer:

As mentioned, pollen-stigma compatibility is essential for a successful pollination and fertilization. Once compatible pollen is accepted by pistil, events for fertilization proceeds, whereas incompatible pollen will be rejected. This interaction where a pistil is capable of recognizing its pollen is the result of long-term pollen-pistil interaction and chemicals released by pollen.

Understanding of pollen-pistil interaction is important in hybridization. It is one of the innovative methods of the crop production improvement program. During artificial hybridization, only the desired pollen grains are introduced to the stigma through pollination. This helps to avoid unwanted pollen rejection and saves time.

Hybridization proceeds in two steps, one is emasculation and another is bagging.

Emasculation: We know hybridization is the method of selective breeding. Thus, anthers have to be removed from a bisexual flower before they release pollen grains. This step of removal of anther using forceps is termed as emasculation. In the case of unisexual flowers, this step is not necessary.

Bagging: Bagging is the protection of emasculated flower from contamination by undesirable pollen grains. Here the flower is masked by a bag, still, the flower attains receptivity. In unisexual flowers, bagging is done before the flowers are open.

Emasculation and bagging ensure that female flower is completely protected from contamination.

Once the flower attains stigma receptivity, the desired pollens are dusted on the stigma. This is resealed for further developments. Hence, artificial hybridization ensures that right type of pollen has transferred to the stigma of the flower. In addition, the chance of fertilization is high. Through this approach, a variety of strains of crops can be developed and it improves the quality of crop with desirable characters.

Answer 2

$\huge{\mathfrak{\red{\underline{\underline{Artificial\;Hybridization}}}}}$

Artificial hybridization is the crossing of two different plants having complementary good traits in order to obtain an overall superior variety. This technique is used by plant breeders for crop improvement programme.

Artificial hybridization of plants involves following steps:

${\mathfrak{\blue{\underline{\underline{1).\;Emasculation:-}}}}}$ The process of removing anthers and stamens or killing the pollen grains of the plant to be used as the female parent in a cross called emasculation. After emasculation, the flower contains only female reproductive organs. So for pollination desired pollen form male plant will be provided by breeder.

${\mathfrak{\blue{\underline{\underline{2).\;Bagging:-}}}}}$ Emasculated flowers or inflorescence is immediately bagged to avoid pollination by any foreign pollen grains. These bags are made up of butter paper, fine cloth or polythene depending on the inflorescence. Male plants which will provide pollen's are also bagged to avoid contamination of pollen with any foreign pollen.

${\mathfrak{\blue{\underline{\underline{3).\;Tagging:-}}}}}$ The emasculated and bagged flowers or inflorescence are tagged bearing the date of emasculation, date of pollination and name of cross with name of female parent followed by X and then name of male parents are keeping proper record of artificial hybridization.

${\mathfrak{\blue{\underline{\underline{4).\;Pollination:-}}}}}$ Mature and fertile pollen grains are collected from male parent, bag is opened and pollen grains are dusted on receptive stigma with the help of brush.

${\mathfrak{\blue{\underline{\underline{5).\;Rebagging:-}}}}}$ After pollination, the flowers are rebagged till the fruits begin to ripen. The fruits contain seeds of hybrid variety.