TRANSMISSION BY ARTIFICIAL MEANS

GRAFT TRANSMISSION

In grafting cut surfaces of tissues of different plants are brought into intimate contact so that they can establish a union. Basically in grafting an isolated

Shoot (scion) or bud is severed from one plant and is joined to the rooted part (root stock) of another plant. The effective union of two produces one plant.

Methods of grafting used for virus transmission are as under.

Ø Bud grafting

Ø Side grafting

Ø Bottle Leaf grafting  Petiole and Cleft grafting

From the above method of transmission through grafting is the petiole and 'left graft, which was used in my internship study.

1.      Bud Grafting

This type of grafting takes the bud from the healthy plant and grafted on the virus affected plant. It gives the quickest result as compared to side grafting. Jut the very small bud is required for the grafting and that's why this method is difficult to adopt.

2.       Side Grafting

This type of grafting the two pants disease and healthy are required. The join the stem of both the plants and bounded with Para film. This method is lot commonly used because two plants are required.

3.     Bottle leaf Grafting

Transferring the disease by implanting leaf petiole or small branch of infected plant onto the healthy plants. In this technique the leaf petiole is placed in a test tube with water until a union is formed (5days). This technique is very reliable, used for old plants but a bit laborious and does not work in high temperature because of evaporation from bottle (test tube).

4.     Petiole and Cleft Grafting

This is a simple technique in which top of the healthy plant is removed a wedge shaped cleft is made on the top of the stem. A diseased leaf petiole end is pointed with a sharp scalpel, is inserted as a scion and bound with a Para film tape. The grafted plants are kept in the glass house or covered with polyethylene bags to avoid the evaporation and to maintain the temperature