Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/1999
Publication Date: N/A
Interpretive Summary: The Russian wheat aphid (RWA), is the most serious pest of wheat grown in the western United States. Growing wheat with genetic resistance to RWA is the best way to produce a wheat crop without worrying about RWA damage. Developing wheat cultivars with resistance to RWA is a long, difficult process that could benefit from an understanding of the genetics, physiology, and biochemical basis of RWA resistance. We analyzed PI 140207 (a spring wheat germplasm line with excellent RWA resistance) to determine the inheritance of resistance, and identify proteins produced in response to RWA feeding that may be involved in the resistance reaction. To determine inheritance of resistance, we crossed PI 140207 with Pavon (a RWA-susceptible spring wheat cultivar) and analyzed their F1, F2, backcross, and F2-derived F3 families. Our results indicated that a single dominant gene controlled RWA resistance in PI 140207. We also looked at protein gels of leaf tissue before and after RWA attack in PI 140207 and Pavon. We found that a specific complex of 24 kilodalton proteins was dramatically reduced in the susceptible Pavon, yet persisted in the resistant PI 140207. The function of this protein complex in resistance is unknown, but our results provide evidence of cellular functions associated with RWA resistance that should be pursued further.
Technical Abstract: The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has become a perennial, serious pest of wheat (Triticum aestivum L.) in the western United States. Current methodologies used to enhance RWA resistance in wheat germplasm could benefit from an understanding of the physiological mechanisms underlying resistance to RWA. This study was initiated to determine the inheritance of RWA resistance in PI 140207 (a RWA-resistant spring wheat) and identify specific polypeptides induced by RWA feeding that may be associated with RWA resistance. Crosses were made between PI 140207 and 'Pavon' (a RWA-susceptible spring wheat). Genetic analysis was performed on the parents, F1, F2, backcross (BC) population, and F2-derived F3 families. Analysis of segregation patterns of plants in the F1, F2, and BC populations, as well as F2-derived F3 families indicated single dominant gene control of RWA resistance in PI 140207. The effects of RWA feeding on PI 140207 and Pavon were examined by visualizing silver-stained denatured leaf proteins separated by two-dimensional polyacrylamide gel electrophoresis. Comparisons of protein profiles of noninfested and RWA-infested Pavon and PI 140207 revealed a 24 kilodalton protein complex selectively inhibited in Pavon that persisted in PI 140207 during RWA attack. No other significant qualitative or quantitative differences were detected in RWA-induced alterations of protein profiles.