Comparative Resistance of Selected Acala 1517 Cotton Cultivars to Meloidogyne incognita Race 3

R. S. Klump, S. H. Thomas


Little information is available regarding the levels of Meloidogyne incognita race 3 resistance in Acala 1517 cotton cultivars compared with cultivars grown outside the southwestern United States. Levels of M. incognita egg production were compared among commercial Acala cultivars 1517-E2, 1517-SR1, 1517-75, 1517-77BR, and SJ-5, resistant and susceptible standards Auburn 634 and M-8 and breeding lines Acala 5701-W and N6072 grown for 45 days in the greenhouse. The Acala 1517 cultivars all performed similarly, demonstrating moderate nematode resistance. Egg production on the 1517 cultivars was less than on SJ-5 and less than one-fifth that on M-8. Auburn 634 was most resistant, followed by N6072. Total egg production per plant and egg production per gram dry root were not correlated but proved to be reliable indicators of relative resistance to M. incognita. Key words: Gossypium hirsutum, cotton, Meloidogyne incognita, root-knot nematode, resistance.

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