Inheritance of resistance to the lentil strain of pea seedborne mosaic virus in Pisum sativum L.

Graduation date: 1989The inheritance mode of pea-resistance to the Lentil\ud Strain of Pea Seedborne Mosaic Virus (PSbMV-L) was\ud studied. In addition, commercial pea cultivars, Plant\ud Introduction (P.I.) lines and Oregon State University\ud (OSU) breeding lines were tested for susceptibility to\ud this virus. These lines were also tested for their\ud reaction to Bean Yellow Mosaic Virus (BYMV) and pathotype\ud 1 of Pea Seedborne Mosaic Virus (PSbMV-Pl) to further\ud elucidate the relationships of Pisum resistance to the\ud three viruses.\ud Susceptible cultivars, 'Sounder', 'Abador', 'Quincy'\ud and 'Avon' were hybridized with resistant cultivars,\ud 'Little Marvel' and OSU B445-66. Data on reaction to\ud PSbMV-L inoculation were obtained for Fl, F2, and F3\ud progeny and selected backcrosses. Fl tests indicated that\ud resistance was recessive. Most F2 populations segregated\ud as ratios of 3 susceptible: 1 resistant indicating that a\ud single recessive gene controls resistance. Populations of\ud most F3 families fit ratios of 3 susceptible or\ud segregating: 1 resistant. The F3 family data fit ratios\ud of 1 susceptible: 2 segregating: 1 resistant in some of\ud the tests. In remaining tests, failure to fit this\ud expected ratio was assumed to be due to random escapes\ud (susceptible, but not infected), or to a klendusic\ud reaction in progenies from 'Quincy'. Segregation of\ud backcrosses from two crosses in a 1 susceptible: 1\ud resistant ratio supported the single recessive gene\ud hypothesis.\ud Of 202 commercial cultivars screened screened for\ud PSbMV-L resistance, 144 were resistant and 58 were\ud susceptible. Cultivars resistant to PSbMV-L were also\ud resistant to BYMV, and cultivars susceptible to PSbMV-L\ud were susceptible to BYMV except for 'Quincy' and 'Avon',\ud which were susceptible to PSbMV-L but resistant to BYMV.\ud All of 9 OSU lines and all 32 of selected P.I. lines\ud tested were resistant to PSbMV-L. The P.I. lines had been\ud previously tested and were known to be resistant to PSbMV-Pl.\ud All 9 OSU breeding lines and all but one P.I. line\ud were resistant to BYMV, indicating a possible linkage\ud relationship between resistance to PSbMV-L and BYMV.\ud Three of 178 cultivars, 27 of 32 P.I. lines, and all of 9\ud OSU breeding lines tested were resistant to both PSbMV-Pl\ud and PSbMV-L. The results suggested that there is a\ud tendency for resistance to PSbMV-Pl and resistance to\ud PSbMV-L to be associated in pea cultivars