Rice tungro bacilliform virus
Encyclopedia
Rice tungro bacilliform virus (RTBV) is a plant pararetrovirus of the family Caulimoviridae
. Tungro means 'degenerated growth' and was first observed in Philippines.
The tungro virus is known to have at least two strains - S and M. The 'S' strain in these varieties produces conspicuous interveinal chlorosis, giving an appearance of yellow stripe and sometimes irregular chlorotic specks on younger leaves. On the other hand, the 'M'strain produces only mottling.
plants are stunted and have reduced number of tillers. The young emerging leaves develop interveinal chlorosis leading to discoloration of the leaves, starting from tip downwards. Often whole leaf
is discolored, plants infected at an early stage generally die prematurely. Infected plants take more time for maturity because of delayed flowering. The panicle
s are often poorly developed and the grain
s are also often covered with dark brown blotches and are lighter than those of healthy plants.
Caulimoviridae
-General overview:The Caulimoviridae are a family of viruses, including the following genera:*Genus Badnavirus; type species: Commelina yellow mottle virus*Genus Caulimovirus; type species: Cauliflower mosaic virus...
. Tungro means 'degenerated growth' and was first observed in Philippines.
Virology
Rice tungro bacilliform virus was first described by Saito in 1975. Galves (1968) purified the virus and reported that the particles are polyhedral with a diameter of 30-33 nanometers. The virus withstands temperatures below 63 degree celsius for 10 minutes.The tungro virus is known to have at least two strains - S and M. The 'S' strain in these varieties produces conspicuous interveinal chlorosis, giving an appearance of yellow stripe and sometimes irregular chlorotic specks on younger leaves. On the other hand, the 'M'strain produces only mottling.
Clinical
Tungro affected riceRice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
plants are stunted and have reduced number of tillers. The young emerging leaves develop interveinal chlorosis leading to discoloration of the leaves, starting from tip downwards. Often whole leaf
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
is discolored, plants infected at an early stage generally die prematurely. Infected plants take more time for maturity because of delayed flowering. The panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
s are often poorly developed and the grain
GRAIN
GRAIN is a small international non-profit organisation that works to support small farmers and social movements in their struggles for community-controlled and biodiversity-based food systems. Our support takes the form of independent research and analysis, networking at local, regional and...
s are also often covered with dark brown blotches and are lighter than those of healthy plants.