Introgression of Reniform Nematode Resistance from G. arboreum to Upland Cotton: 2005 Advances

Accordingly to the Arkansas Nematode Diagnostic Clinic 00 (Cooperative Extension Service, 00 ) the reniform nematode (Rotylenchulus reniformis Lindford and oliveira) (RN) is present in twelve counties in the state where most of the cotton (G. hirsutum) is cultivated. In fields infested with RN, yield losses are estimated at 340 to kg/ha (Robinson, 001). The RN is expected to become an even greater threat in the future with its continued spread into uninfested cotton-production areas and with expansion of cotton acreage (Gazaway and McLean, 00 ; Monfort and Kirkpatrick, 00 ). Up to now, in the absence of resistant cultivars, nematicides and crop rotation were the only available methods for controlling the reniform nematode (Stewart and Robbins, 1 ). The objectives of this study were to (a) develop reniform nematode-resistant lines in early backcross generations as germplasm sources for cultivar development, and (b) identify molecular markers linked to RN resistance for use in marker-assisted selection (MAS) breeding programs.