Screening field pea germplasm for resistance to downy mildew (Peronospora viciae) and powdery mildew (Erysiphe pisi)

Control of winter forage pea diseases by pea-oat intercropping under field conditions

“…The pathogen infects all aerial parts (leaves, stems, flowers, pods) of pea plants (Singh, 2000), and can cause significant yield losses (Kumar & Singh, 1981;Davidson et al, 2004).…”

Resistance to downy mildew (Peronospora viciae) in Australian field pea germplasm (Pisum sativum)

“…The punnets were placed into trays (40 × 29 × 6 cm), with each tray containing 20 punnets, and water of 1 cm depth was maintained in the trays. After 7 days incubation in the CER at 12°C/4°C seedlings were inoculated with the P. viciae populations, as described by Davidson et al (2004), each population inoculated onto one complete tray per replicate. The experiment was arranged in a randomised block design with 4 replicates.…”

Screening techniques and sources of resistance to rusts and mildews in grain legumes

“…In fact, mixtures of isolates were collected from as wide an area as possible for use in inoculation tests in the United Kingdom in order to evaluate cultivar resistance (Yanase et al, 1995). Similarly, in Australia, several isolates were mixed together for resistance screening of field peas in controlled conditions (Davidson et al, 2004). Taylor et al (1989) suggested that the diversity of P. viciae would make monogenic dominant resistance short-lived, while polygenic resistance would be more likely to be long-lasting.…”

“…This method is a good way to produce inoculum for further experiments although conidia may also be stored for at least 1 year on pea leaves under ultra-low temperatures (−80 • C) as a source of inoculum (Gill & Davidson, 2005; Spencer-Phillips & Ferenc, personal communication). Davidson et al (2004) achieved systemic downy mildew infection through inoculating 7-day-old pea seedlings by placing four droplets of a 1 × 10 6 spores/ml of conidial mixture of at least five populations into the apical buds. Plants were incubated for 4 days at 4 • C in high humidity and then for 17 days at 12 • C/4 • C day/night cycles, after which the low temperature and high humidity was re-applied for a 48 h period in order to stimulate sporulation.…”

“…Taylor et al (1989) used a 0-4 scale to classify pathotypes of P. viciae in the UK where 0 = very resistant (no symptoms), 1 = resistant (local necrosis, no sporulation), 2 = moderately resistant (limited conidial production, local necrosis), 3 = susceptible (abundant conidia on inoculated leaves), 4 = very susceptible (abundant conidia, often with systemic infection). Davidson et al (2004) Davidson et al (2004) assessed resistance based on sporulation using a 0-4 scale where 0 = no sporulation on plant; 2 = sporulation on 10-30% of leaf and stem; and 4 = sporulation on greater than 70% of leaf and stem. The reactions of the check lines were used to place the test lines into response categories of resistant (mean score <0.75), moderately resistant (mean score 0.75-0.99), moderately susceptible (mean score 1.0-1.99) or susceptible (mean score ≥2.0).…”