Abstract
Pedigreed natural crossing has been suggested as a technique for increasing the number of hybrids in peanut (Arachis hypogaea L.) breeding programs, when used in conjunction with the conventional crossing procedure. Since the success of this technique is dependent upon the natural crossing frequencies, a study was conducted from 1984-1986 to determine the current natural crossing frequency in Virginia peanut breeding plots. The cultivar Florigiant was used as the female parent, and the genetic line Krinkle was used as the male parent in a field plot each year. Krinkle has a dominant leaf characteristic easily identified in the hybrid progeny. Seed harvested from the Florigiant parent were planted in subsequent years, and the percentage of Krinkle plants determined for calculating the frequency of outcrossing. The frequency varied with environment from 2.8% in 1984 to 0.0% in 1986. The rate in 1984 was about four times the amount of natural crossing previously reported in Virginia. These results indicate that isolation distances between cultivars in seed fields may need to be greater than in current regulations, and cultivars need to be closely rogued for off-type plants during seed increase.
Author notes
1Cooperative investigation of U.S. Department of Agriculture, Agricultural Research Service and Virginia Polytechnic Institute and State University, Tidewater Agricultural Experiment Station, Suffolk, VA.