SCREENING CULTIGENS OF CUCUMBER AND HORNED CUCUMBER FOR RESISTANCE TO ROOT KNOT NEMATODES

Abstract

Root knot, caused by Meloidogyne spp. is the most important disease of cucumber (Cucumis sativus L.) in North Carolina, causing an average annual yield loss of 12 %. A greenhouse study was conducted 10 screen 924 cultigens (728 accessions, 136 cultivars and 36 breeding lines of C. sativus, and 24 accessions of C. metuliferus Naud.] for resistance to 3 species of root knot nematodes, M. incognita r. 3, M. arenaria r. 2 and M. hapla, Plants were grown from seed in 150-mm diameter clay pots. Two-week-old seedlings were inoculated with 5000 nematode eggs per plant, then evaluated for resistance 9 weeks later. All cultigens evaluated were resistant to M. hapla. Little resistance was found in the cultigens of C. sativus to M. incognita r. 3 and M. arenaria r. 2. Most of the cultigens evaluated were susceptible to both. `Southern Pickler' was resistant to both nematodes (1 % average galls). `Green Thumb and LJ 90430 were resistant to M. arenaria r. 2, Two check cultigens, `Sumter' and Wis. SMR 18, had an average of more than 50% galls. All C. metuliferus cultigens evaluated were resistant to all root knot nematodes tested. PI 482452 was most resistant (1 % average galls), and PI 482443 was least resistant (5% average galls) of the C. metuliferus cultigens tested.