Three Pea Seedborne Mosaic Virus Pathotypes from Pea and Lentil Germ Plasm

Abstract

two true leaves expanded and again 1 wk Alconero, R., Provvidenti, R., and Gonsalves, D. 1986. Three pea seedborne mosaic virus later unless otherwise mentioned. pathotypes from pea and lentil germ plasm. Plant Disease 70:783-786. Virus and CIP purification. The method of Yeh and Gonsalves (18) was Three isolates of pea seedborne mosaic virus (PSbMV), P-l and P-4 from pea (Pisum sativum) and used to purify CIP from plants infected L-l from lentil (Lens culinaris) germ plasm accessions, were distinguished by their capacity to infect with isolates P-1 and L-I. The two virus pea genotypes. Resistance in peas was isolate-specific. Resistance to the L-l isolate was associated with bean yellow mosaic virus resistance and also with a delayed reaction to isolate P-4. Several pea isolates were purified according to the germ plasm accessions were resistant to all three isolates. All isolates were infective to 26 genetic method of Dougherty and Hiebert (5) lines of chickpea (Cicer arietinum), a new host, but not to 12 accessions of pigeon pea (Cajanus with some modifications. Infected shoots cajan). Antisera produced against the cytoplasmic inclusion protein induced in peas by P-l and L-I of Ranger pea were harvested and frozen were useful in detecting infections by the indirect ELISA method and were generally more sensitive 24-28 days after inoculation. Tissues than antisera to the viral protein. were homogenized in cold potassium phosphate buffer (0.5M, pH 7.5, with 0.1% Na 2SO 3 and 0.01 M ethyleneGerm plasm collections of pea (Pisum Breeding for resistance to PSbMV in diaminetetraacetic acid) at 2 ml/g of sativum L.) and lentil (Lens culinaris peas may be affected by the kind of plant and carbon tetrachloride at 0.5 ml ofeach Medik.) may not only be reservoirs for response to infection. For example, pea per gram of tissue for an additional pea seedborne mosaic virus (PSbMV) but progenies from certain apparently minute. The homogenate was centrifuged also valuable sources of resistance to this PSbMV-immune parents may show at4. The supentantuwas pathogen (3,10,12,13,17). Resistance in susceptibility to the virus only after a saved, and the pellets were resuspended in pea to the common strain of PSbMV is series of inoculations (11). Likewise, the sa te bf and et rifug ed reported to be conditioned by a single variety of plant responses to PSbMV for 5 min. The combined supernatants recessive gene, designated sbm by infection m ay affect virus eradication were5 cein ifuge atm1,00 g fore5 minnth Hagedorn and Gritton (8). Infection in procedures when slow development of were centrifuged at 1,000 g for 5 mm, the pellets were discarded, and the supernatant this host species may be latent or may be the virus in test plants results in delays in was centrifuged at 10,000 g for 20 mn. At expressed by a wide variety of symptoms detection with bioassay or serological this stage, the pellets contained the ranging from rapid and lethal to delayed methods (2,9). The interaction between cytoplasmic inclusions and the superand transitory (11,15). This variety of PSbMV and pea or lentil becomes more natant ineduthenvirus The viru plant responses in pea has suggested a apparent as we study more representatives precontated by ving The ne modifier-gene system affecting resistance of the host and pathogen. The followin glycol (PEG, mol wt 8,000,4% [w/v] final to this virus (11). Recently, variants of report distinguishes three isolates of concentration) while stirring for 1.5 hr at PSbMV have failed to infect pea cultivars PSbMV by differential responses of pea 4 C. The precipitated virus was collected susceptible to the common strain but genotypes to infection, demonstrates the by centrifugation at 10,000 g for 10 min resistant to bean yellow mosaic virus value of cytoplasmic inclusion protein and resuspended in 40 ml of 0.02 M (BYMV). Gene mo, responsible for (CIP) antisera to detect the virus in plant phosphate buffer, pH 8.2, with 0.1% 2resistance in peas to BYMV, has been tissues, and notes a new leguminous mercaptoethano . The virus preparation reported to confer resistance to these species, chickpea (Cicer arientinum L.), was centrifuged in 30% (w/v) CsCi