Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/9/2001
Publication Date: N/A
Interpretive Summary: There are many kinds of microscopic worms called nematodes that feed on the roots of cotton and other crops, debilitating the plants and markedly decreasing yields. The direct losses to U.S. cotton farmers caused by nematodes were estimated by the National Cotton Council in 1999 to exceed $300,000,000. Although several different kinds of nematodes attack cotton, the reniform nematode and the cotton root-knot nematode are the most important in the U.S. A small number of cotton cultivars are resistant to the root-knot nematode but none are resistant to the reniform nematode. This publication briefly reviews the information available today regarding genetic sources of resistance to the reniform nematode among several thousand wild cotton varieties whose seed are maintained in the U. S. cotton collection. These varieties are not suitable for cotton production on a farm because the cotton lint they produce is insufficient or of low quality. However, nematode resistance genes in them can be transferred into agronomic varieties to make it possible for farmers to produce high quality cotton lint profitably in areas where nematodes are a serious problem.
Technical Abstract: Most research on cotton nematodes has been on the cotton root-knot nematode, Meloidogyne incognita. The reniform nematode (Rotylenchulus reniformis) is a relatively new and fundamentally different problem. It already has become apparent that the best ways to manage this nematode will be different as well. Root-knot nematode-resistant cultivars have been developed from G. hirsutum germplasm but the development of reniform nematode-resistant cultivars probably will require the transfer into Upland cotton of nematode resistance genes form other species of Gossypium. The most promising sources of resistance are within the species G. barbadense, G. longicalyx, and G. arboreum.