THE REACTION OF SOME VARIETIES OF FABA BEAN (VICIA-FABA L) TO PEA SEED-BORNE MOSAIC POTYVIRUS

Pea seed-borne mosaic potyvirus (PSbMV) causes an economically importa nt disease found wherever peers (Pisum sativum L.) are grown. The viru s has also been found to infect faba bean (Vicia faba L.). The suscept ibility and sensitivity of three coloured-flowered and three white-flo wered commercial varieties of faba bean following mechanical inoculati on with three pathotypes of PSbMV was investigated. The effects includ ed the expression of mosaic symptoms, stunting, and the production of abnormal, poor qualify seed. Infection with pathotype P-4 had generall y less severe effects on plants than infection with pathotypes P-1 and L-1. All the varieties produced some abnormal seed, but there was a h igher proportion produced by white-flowered than by coloured-flowered varieties when inoculated with pathotypes P-1 and P-4. The amount of t ransmission of the virus through seed was comparable to that occurring with many pea varieties. Varietal resistance to infection with PSbMV was also noted.