Scientists track cause of mystery paddy dwarfing in Punjab and Haryana

Subject :Agriculture

Context :

Agriculture scientists have narrowed down the cause of a mystery disease causing “dwarfing” of rice plants in Punjab and Haryana to either grassy stunt virus or phytoplasma bacteria.
The vector responsible for their transmission is the brown plant hopper, an insect pest that sucks sap from the stems and leaves of rice plants.
Scientists at the Indian Agricultural Research Institute (IARI), who had collected samples of plants from farmers’ fields – which showed symptoms of stunting and yellowing — have undertaken their electron microscopy analysis and DNA isolation through PCR (polymerase chain reaction) technique.

“Phytoreovirus” or rice grassy stunt virus

Preliminary laboratory analysis indicates the “phytoreovirus” or rice grassy stunt virus as the source of infection. This virus, which induces stunting and yellowing of rice plants, is transmitted by brown plant hopper.
The infected plants remained stunted even after application of the recommended dose of fertilizers

Phytoplasma

The second possible source is phytoplasma, a bacterial pathogen that is spread by both brown plant hopper and green leaf hopper sucking insect pests.

IARI scientists are also not ruling out fusarium fungus and rice root nematode that are known to cause dwarfism