ARS | Publication request: EVALUATION OF ARACHIS HYPOGAEA X A CARDENASII INTERSPECIFIC LINES FOR RESISTANCE TO INSECTS

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 6, 1997
Publication Date: N/A

Interpretive Summary: Resistance to insects is one the most efficient, economical means of preventing plant damage by pest insects. Only marginal levels of resistance to insects have been found in many of the cultivated peanut accessions, and, when crossed with a more susceptible line, produces little or no resistance that can be used. Conversely, high levels of resistance have been identified in some of the wild species of peanut. However, many of the wild species are not compatible with the cultivated species due to difference in their chromosome number. Dr. H. T. Stalker of North Carolina State University crossed a wild species (Arachis cardensaii) of peanut with a cultivated type (Arachis hypogaea) and obtained fertile offspring. We evaluated several lines selected from this interspecific cross for resistance to insects. Laboratory bioassays showed variable resistance to the corn earworm, no resistance to the fall armyworm, and moderate resistance in line IC 2-5 to the velvetbean caterpillar. Damage ratings for insects in the field showed no resistance among the interspecific lines to tobacco thrips, but high levels of resistance to the potato leafhopper and southern corn rootworm. The levels of resistance in the interspecific lines to the southern corn rootworm and potato leafhopper should prove useful in a breeding program to develop commercial peanut lines with resistance to these insects.

Technical Abstract: Fourteen lines from the interspecific cross Arachis hypogaea X A. cardenasii were evaluated in the field and seven lines in the laboratory for resistance/susceptibility to insects. Laboratory evaluation of interspecific lines against major defoliators of peanut showed variable levels of resistance to the corn earworm, no resistance to the fall armyworm, and moderate resistance to the velvetbean caterpillar as noted by a reduced host suitability index in line IC 2-5. Damage ratings to plants in the field indicated no resistance in the interspecific lines to the tobacco thrips. However, a high level of resistance to the southern corn rootworm was observed in most of the lines. Resistance to the potato leafhopper was indicated by reduced damage ratings for all interspecific lines relative to damage on cv. Florunner. Resistance ratings for the potato leafhopper were highest in lines IC 1-16 and IC 1-19 and was evident even under severe potato leafhopper pressure. The levels of resistance to the southern corn rootworm and potato leafhopper should prove useful in a breeding program to introgress resistance to these insects into elite cultivars.