Bacteria and viruses

PLANT VIRUSES are viruses that can infect plants. Like other viruses, they are unable to multiply outside the host's body. They are important pests of trees and trusses. Viruses are infectious diseases transmitted by propagating material or by animals - vectors. Its occurrence is best identified from the symptoms on plants. There are currently no effective measures to suppress them.

Known plant-damaging viruses include a scarlet virus, tobacco mosaic virus, grapevine leafroll, and others.

The harmful effects of viruses are manifested by a loss of color and progressive degradation of plant tissues. Color changes on leaves and tissues are common. The infested plant gradually withers and eventually dies.

The spread of viruses into the environment is not as massive as, for example, the spread of fungi. Fungi can emit spores in huge quantities and infect plants in a wide area relatively quickly. The spread of viruses is limited due to their restricted ability to exist outside the host organism. From a practical point of view, the transmission of viruses during reproduction is of the utmost importance. Viruses are transmitted from an infected plant during reproduction - inoculation, grafting, etc. Animals are also important vectors, especially nematodes, insects, snails, and the like.

Identification of the presence of viruses is made based on symptoms. Accurate identification of viruses is very complicated and requires special laboratory procedures (ELISA test, etc.).

BACTERIA penetrates plants most often through injuries.

They cause:

1. necrosis (Xanthomonas, Pseudomonas)

2. rot (Erwinia)

3. tumors on branches or roots (Agrobacterium tumefaciens)

4. wilting and yellowing of assimilation organs.