Combination of root-knot nematode (meloidogyne spp.) resistance and edible seed quality for peanut (arachis hypogaea L.) production in Mozambique and in the U.S.

ABSTRACT Crosses were made to begin the development of peanut populations that are adapted to Mozambique with high oleic fatty acid content and/or resistance to root-knot nematodes. Two low oleic PI’s (PI 268573 and PI 268673) introduced from Zambia were crossed with two high oleic varieties (Tamrun OL01 and OLin) to develop high oleic progeny adapted to Mozambique. Previous studies that the high oleic trait is controlled by two recessive genes were confirmed, and the results of this study suggest the existence of additive gene action for the high oleic trait on peanuts. Segregation in two of the populations suggests that the high oleic trait may be controlled by three genes. The two PI’s were crossed with one root-knot nematode resistant variety to develop peanut populations that are resistant to root-knot nematodes and adapted to Mozambique. Also, the two high oleic varieties were crossed with one root-knot nematode resistant variety (NemaTAM) in order to develop lines which are high oleic as well as root-knot nematode resistant. Existing Spanish x Valencia crosses were evaluated from single plants (2002) to twin rows (2004). The purpose for this evaluation was to find good yielding peanut lines with high oleic and early-maturing for the Southwest U.S. (West Texas and Eastern New Mexico). In 2002, 53 lines were selected from 700 single plants using a combination of plant, high-oleic fatty acid content, maturity, and number of seeds per pod as selection index. These lines were planted in 2003, and 24 releasable lines with high-oleic fatty acid content, early-maturing, Spanish or Valencia characteristics, and high-yielding were selected and planted in 2004 in three locations. Several Spanish and Valencia lines have potential for development into varieties.