Cabbage

Evaluations carried out by Institute National de Recherche Agronomique, Rennes, France, as part of the RESGEN project.

Plasmiodophora brassicae: Testing of plantlets after artificial inoculation under glasshouse conditions. Accessions are tested in a randomised block design with 2 replicates (20 plants per replicate). Applying 1ml of the spore suspension at the bottom of the stem (pipette method). Scoring method:evaluation of the swelling of the roots, 6-8 weeks after inoculation: 0 = no visible swelling; 1 = very slight swelling usually confined to lateral roots; 2 = moderate swelling on lateral roots and taproot; 2+ = severe clubs on all roots but some roots remain; 3 = no roots left, only one big gall.

Two field isolates of Plasmodiophora brassicae, respectively derived from two field populations of galls of naturally infested rapeseed and cauliflower crops grown in two different historical cole cropping areas in Brittany (north-western region of France), are used in the resistance tests. Both isolates are characterised for pathogenicity on three differential B. napus cultivars as described previously by Somé et al. (1996). The isolates are propagated on Chinese cabbage (B. rapa spp. pekinensis cv. Granaat); the clubs are harvested, washed and stored at -20 °C until required.

A disease index (DI) calculated by summation of the coefficients (0, 25, 50, 75 and 100) affecting each class frequency DI=(0 x n0) + (25 xn1) + (50 x n2) + (75 x n2+) + (100 x n3) / (n0+n1+n2+n2+ + n3)

Evaluations carried out by Plantum NL (7 companies involved), Gouda, the Netherlands, as part of the RESGEN project.

Xanthomonas campestris resistance measurements: Glasshouse trial, temperature 25°C Plant stage at inoculation: 7-10 days after sowing or until cotyledons are fully expanded Isolate: from IPO-DLO (now PRI) Wageningen Inoculation method: briefly dip round wood tooth picks in inoculum, make a single puncture through the midvein of the cotyledon near the margin.

% of plants in three classes: Resistant, Partial Resistant, Susceptible.

Mean disease index: Σ(no. plants in scale n * n) / total no. plants

Micosphaerella brassicicola resistance measurements:

% of plants in three classes: Resistant, Partial Resistant, Susceptible.

Mean disease index: Σ(no. plants in scale n * n) / total no. plants