| Abstract: | Heterodera cajani is an important nematode pest of pigeonpea in India and a simple and reliable greenhouse procedure has been developed to screen pigeonpea genotypes for resistance to it. In pot experiments, white cysts of H. cajani were counted on the roots of the susceptible genotype ICPL 87 at 15, 30 and 45 days after seedling emergence in soils infested with different levels of H. cajani. The seedlings were rated for the number of white cysts per root system on a one (highly resistant, no cysts) to nine (highly susceptible, more than 30 cysts) scale. White cysts were not easy to see on wet roots but were clearly visible on slightly dried roots. Cyst counts and ratings were more uniform when roots of 30 day old seedlings were evaluated than when 15 or 45 day old seedlings were examined. Effects of different H. cajani infestation levels on the ratings were not significant although the use of higher inoculum densities (16 to 27 eggs and juveniles/cm3 soil) was effective in reducing variability. This procedure was used to screen 60 pigeonpea genotypes and all of them were rated seven or nine. Ten accessions of Atylosia spp. and Rhynchosia spp. were rated three. |
