Comparison of Diuraphis noxia resistance in wheat isolines and plant introduction lines

Abstract

The Russian wheat aphid, Diuraphis noxia (Mordvilko), is one of the most important aphid pests of wheat, Triticum aestivum L., worldwide. Among the various pest management options, plant resistance is an economical management tactic to control D. noxia in cereal crops such as wheat. Researchers have identified D. noxia resistant germplasm and it has been incorporated into wheat. This study compared D. noxia resistance between the 'Betta' wheat isolines Betta-Dn1, Betta-Dn2, and Betta-Dn5 and their corresponding donor gene plant introduction (PI) lines PI 137739 (Dn1), PI 262660 (Dn2), and PI 294994 (Dn5). Although the Betta isolines and PI lines showed D. noxia resistance when compared with Betta wheat, the degree of resistance in the isolines to D. noxia was different from their corresponding PI donors. Aphid number, aphid fecundity, and biomass per aphid were not different between Betta-Dn1 and PI 137739 or Betta-Dn2 and PI 262660; however, the same parameters were significantly lower on PI 294994 compared with Betta-Dn5. This indicated that aphid resistance in PI 137739 and PI 262660 was probably governed by a single dominant gene, while the resistance in PI 294994 was controlled by more than one gene. Additionally, plant biomass reduction was aphid density dependent, which suggested that use of appropriate aphid infestation level is important when using plant biomass reduction as an indicator of resistance. Plant resistance categorization showed that there was no detectable difference in antixenosis among the seven lines evaluated. However, the higher aphid fecundity observed on PI 262660 compared with PI 137739 and PI 294994, in addition to no significant differences among the three PIs in plant biomass reduction, suggested PI 262660 was a tolerant line, while PI 137739 and PI 294994 were antibiotic lines. Plant tolerance could not be elucidated among the three Betta isolines using aphid fecundity and plant biomass reduction as indicators.

Aphid (Hemiptera: Aphididae) Resistance in Wheat Near-Isogenic Lines

“…2B). Budak et al (1999) observed similar results when compared the biomass of D. noxia collected from different ÔBettaÕ wheat lines with the same Dn genes. They concluded Betta-Dn5 did not show the same level of resistance to D. noxia as the donor line PI 294994 and suggested that resistance inherited from PI 294994 might be controlled by more than one gene.…”

Impact of <I>Diuraphis noxia</I> and <I>Rhopalosiphum padi</I> (Hemiptera: Aphididae) on Primary Physiology of Four Near-Isogenic Wheat Lines

“…Both aphid species were preconditioned following procedures by Budak et al (1999). To infest wheat plants, either 0 or 15 aphids were introduced onto the second fully expanded leaf blade by using a camelÕs-hair brush.…”

Comparison of Chlorophyll and Carotenoid Concentrations Among Russian Wheat Aphid (Homoptera: Aphididae)-Infested Wheat Isolines

“…Interactions between Betta (susceptible parent) wheat (Du Toit 1988) and its two isogenic lines (Betta-Dn1, antibiosis and Betta-Dn2, tolerance) (Du Toit 1989, Budak et al 1999) challenged by two D. noxia densities (0 and 20 aphids) were evaluated in this study. Plants from each of the three wheat lines were infested with 20 D. noxia at 14 d after planting.…”