Short essay on Anemophily

In this case, plants are pollinated by wind. The flowers are inconspicuous and small. They are never coloured and showy. They neither emit any odor nor secrete any nectar to attract the insects. However, the pollens are produced in enormous numbers. They are light and dry.

Such pollens are easily carried away by wind and transferred to the stigmas. The occurrence of branched bushy stigma and comparatively large protruding stigma in grasses, bamboos, cereals, millets, sugarcane and other such plants help wind pollination. In Zeal Mays, (the male flowers are born in a terminal panicle of spikelets.

A few female spa dices are borne, each in a axil of leaf surrounded by spates. The style consists of long and silky threads. These are seen to hang i tufts from the spandex. When the anthers burst a cloud of pole grains, these float in air close round the plant.

Ilydrophily This type of pollination takes place in aquatic plants. Water is the medium for transfer of pollen grains. Particularly, the submerged plants are adapted for this type of pollination e.g. Nqja, Vallisneria, Ilydrilla etc.

There arc two possibilities, either pollination takes placc completely under water or it takes place on the water surface. In the former case, it is known as hypohydrogamous (example – Najas) while in the latter, it is known as epihydrogamous. (Example – Vallisneria, Ilydrilla). In Vallisneria, the plant grows in mud.

It is dioecious and leaves arc strap shaped. The male plant bears male flowers in small spadix surrounded by spathe. These arc short stalked and borne low down amongst radical leaves. The female flowers are borne singly on long wiry stalks enabling the flowers to float on water when mature.

The individual male flowers get detached and float freely in large numbers on the water surface. These flowers open on the water surface exposing two stamens vertically. The male flowers cluster around the female flower. As anthers burst and the sticky pollen grains get attached to the stigma.

Advantages of cross pollination

(1) This always results in much healthier offspring’s.

(2) The offspring’s produced in this method are better adapted ones.

(3) As a result of the cross pollination, hybrids are produced.

(4) More abundant and viable seeds are produced which store greater quantities of food material.

(5) The process eliminates defective characters and is helpful in production of new varieties.

Disadvantages:

(1) This is wasteful process as large number of pollen grains gets damaged in the course of pollination.

(2) The chance of fertilization is limited here since it can be affected only if the pollen reaches the matured stigma.