Inheritance of Resistance of PI 372129 Wheat to the Russian Wheat Aphid

Abstract

Knowledge of the inheritance of resistance to pests in wheat (Triticum aestivum L.) is important to plant breeders. A study was conducted to determine the inheritance of resistance to the Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), in a wheat line, PI 372129, that was previously identified as a good source of RWA resistance. The susceptible wheat cultivars Carson, Lamar, and TAM 107 were crossed with PI 372129. The parents and progenies from these three crosses were artificially infested with RWA in the greenhouse. There was close association between leaf chlorosis and leaf rolling, two components of the RWA damage rating system. Seedling reactions of the F1, F2, and backcross generations indicated that a single dominant gene governs RWA resistance in PI 372129. Data describing the mechanism of RWA resistance of PI 372129 indicate that this gene is probably different from Dnl and Dn2 (identified in PI 137739 and PI 262660, respectively). Reciprocal crosses revealed no evidence of cytoplasmic effects.

Inheritance of resistance to Russian wheat aphid in barley

“…These scores are similar to those reported by Calhoun et al (1991a) for the same genotypes planted in hill plots of 10 plants and scored at three growth stages in 1989/1990. Du Toit (1989 and Nkongolo et al (1991) investigated the inheritance of resistance to D. noxia in wheat in the greenhouse. The greenhouse is a convenient place to do such work, but plants grow under artificial conditions which could affect resistance and symptom expression.…”

“…Resistance to D. noxia was reported to occur in spring barley germplasm developed by the ICARDA/CIMMYT (International Center for Agricultural Research in the Dry Areas/ International Maize and Wheat Improvement Center) barley programme . Inheritance studies in wheat indicated that resistance to D. noxia is simple (Du Toit, 1989;Nkongolo et al, 1991). However, little is known about inheritance of resistance in barley.…”

Genetic mapping of resistance to Diuraphis noxia (Kurdjumov) biotype 2 in wheat (Triticum aestivum L.) accession CI2401

“…Standard seedling screening procedures were employed for evaluation of RWA2 resistance (Nkongolo et al 1991). RWA screening was conducted at the CSU Insectary under ambient conditions (14 h and *25.5°C with light intensities between 1,100 and 1,400 lM m 2 s -1 and 10 h and *20°C nights).…”

“…Seedlings at the one-leaf stage were infested with RWA2 as described in Nkongolo et al (1991). Symptom development was assessed at 7 and 14 d after infestation, and was scored for leaf rolling and chlorosis.…”

“…These genes have been designated as Dn1 to Dn9, Dnx, Dny, Dn2414 and Dn626580 (Du Toit 1987Toit , 1988Toit , 1989Du Toit et al 1995;Liu et al 2001Liu et al , 2002Liu et al , 2005Ma et al 1998;Marais and Du Toit 1993;Marais et al 1994;Miller et al 2001;Nkongolo et al 1991;Peng et al 2007;Saidi and Quick 1996;Schroeder-Teeter et al 1993;Valdez et al 2012). Resistant cultivars released in the U.S.A. have mainly relied on the single, dominant resistance gene Dn4 (Collins et al 2005b;Quick et al 1996).…”