Effects of Seedborne Potato Virus Y Infection in Two Potato Cultivars Expressing Mild Disease Symptoms

Abstract

The effects of seedborne potato virus Y (PVY) in Shepody and Russet Norkotah, two new cultivars that express mild disease symptoms, were determined by comparing tuber yield and specific gravity of plants grown from PVY-infected seed with those of adjoining plants grown from virus-free seed. Seedborne PVY-infected Shepody plants produced 28.7% less total yield in 1994, and 41.1 and 47.3% less in two trials in 1995. Marketable yield was reduced 55.8 and 79.4% in 1995 trials. PVY infection did not affect specific gravity in Shepody. Seedborne PVY infections in Russet Norkotah reduced total yield by 45.5 and 48.8% in the 1994 and 1995 trials, respectively. During the 1995 trial, marketable yield from seedborne infected plants was reduced 65.1% compared with adjacent plants grown from noninfected seed. Additionally, specific gravity was lower for tubers from seedborne infected Russet Norkotah plants than from plants grown from noninfected seed in 1994. Seedborne infected plants of both varieties had fewer and smaller tubers than did plants grown from virus-free seed. No compensatory yield increase was measured for plants originating from PVY-free seed and growing adjacent to seedborne infected plants for either variety. Rather, yield reduction was observed in Russet Norkotah plants growing adjacent to seed infected plants in 1995. Enzyme-linked immunosorbent assay (ELISA) on Shepody in 1995 showed most plants grown from PVY-free seed became infected within 6 weeks of emergence.

Potato virus Y: An Evolving Concern for Potato Crops in the United States and Canada

“…These symptomless carriers are also good sources of virus that is spread to neighboring crops. Tolerant cultivars infected with PVY and expressing mild or transient symptoms have reduced yields, and virus is readily acquired from such plants by aphids and spread among other susceptible cultivars (39,77,78,91). Many cultivars are included in the "tolerant" category (http://oregonstate.edu/potatoes/latent to PVY list.htm), but cultivars Shepody and Russet Norkotah are two of the most problematic, and they are widely grown, accounting for over 12 and 5% of the total U.S. and Canadian seed acreage, respectively, in 2009.…”

The use of test tube plantlets for the assessment of Potato virus Y transmission by Myzus persicae and Aphis glycines

“…All plantlets survived well during the complete course of experiments, indicating that the medium was rich enough to sustain the plant growth and/or vigor essential for the test. However, the symptoms, mainly mosaic, were not severe enough to warrant a clear-cut diagnosis at least partially due to the mild symptom expression of PVY infection in 'Shepody' (Hane and Hamm 1999). Of the 105 test tube plantlets inoculated by single aphids, 35 became PVY-positive, giving a transmission efficiency of 33.3%.…”

Planter Skips and Impaired Stand Favors Potato Virus Y Spread in Potato

“…High PVY levels can cause stand loss, reduced yields, undersized tubers, and reduced quality (Beemster and de Bokx 1987;Hane and Hamm 1999). Seed borne PVY infection can reduce yield, from 29% to 79% in Shepody and from 46% to 65% in Russet Norkotah (Hane and Hamm 1999).…”

“…High PVY levels can cause stand loss, reduced yields, undersized tubers, and reduced quality (Beemster and de Bokx 1987;Hane and Hamm 1999). Seed borne PVY infection can reduce yield, from 29% to 79% in Shepody and from 46% to 65% in Russet Norkotah (Hane and Hamm 1999). Over the past 20 years, PVY has become an increasingly serious constraint to North American seed potato production Radcliffe and Ragsdale 2002).…”