Categories of Resistance at Different Growth Stages in Halt, a Winter Wheat Resistant to the Russian Wheat Aphid (Homoptera: Aphididae)

Abstract

This study was designed to categorize the resistance to the Russian wheat aphid, Diuraphis noxia (Mordvilko), resistant hard red winter wheat, Halt, as compared with susceptible wheat, TAM 107, at four different growth stages. Antixenosis was expressed in Halt at growth stage Zadoks 30. Antibiosis in Halt affected fecundity, number of aphids produced per reproductive day, maximum number of nymphs produced in one day, and intrinsic rate of increase. Fecundity was lower on Halt than TAM 107, and more nymphs were produced on both varieties at growth stage 20 than 10 and 40. Fewer nymphs were produced per reproductive day and on maximum production days by aphids reared on Halt than by those reared on TAM 107. The intrinsic rate of increase of Russian wheat aphids reared on Halt was lower than aphids reared on TAM 107. Differences in plant height and plant dry weight did not occur. Chlorosis ratings showed greater damage at the earlier stages in Halt and TAM 107 and significantly more damage in TAM 107 than Halt at growth stages 10, 20, and 30. Leaf rolling occurred on infested plants of TAM 107 at growth stages 10, 20, and 30, but not growth stage 40. Halt plants did not exhibit leaf rolling. The presence of a significant level of tolerance could make Halt compatible with other integrated pest management programs. However, care should be taken with cultivars containing evidence of antixenosis or antibiosis that could cause selective pressure on the Russian wheat aphid, potentially causing biotypes to be produced.

Physiological and Biochemical Responses of Resistant and Susceptible Wheat to Injury by Russian Wheat Aphid

“…All experimental plants grew signiÞcantly taller over the course of the experiment (F ϭ 27.2; df ϭ 2, 121; P ϭ 0.0001). Hawley et al (2003) also found no signiÞcant differences in plant height between D. noxia-infested resistant (Halt) and susceptible (TAM 107) plants.…”

“…The resistant Halt and Prairie Red both carry the Dn4 gene (Quick et al 1996, Hawley et al 2003. Three seeds of each cultivar were planted in a Cone-tainer to a depth of Ϸ2 cm in a mixture of sandÐsoilÐpeatÐperlite (0.66:0.33:1:1) and placed in Cone-tainer racks.…”

“…The resistant Prairie Red and Halt supported similar numbers of aphids throughout the experiment, demonstrating that the two resistant cultivars display tolerance to D. noxia. Studies by Randolph et al (2005a) and Hawley et al (2003) have previously characterized Prairie Red and Halt as conveying tolerance in the seedling stage and antibiotic properties at later stages of development.…”

“…Wheat cultivars containing D. noxia-resistant genes, which have different levels of antibiosis, tolerance, or both (Randolph et al 2005a), have been shown to harbor fewer D. noxia populations and have higher yields compared with their susceptible wheat counterparts (Randolph et al , 2005b. Resistant plants also have demonstrated compatibility with other management tactics by exhibiting an absence of leaf rolling when infested with D. noxia, which would expose the aphids to chemical and biological management (Hawley et al 2003).…”

Categories of Resistance to Greenbug and Yellow Sugarcane Aphid (Hemiptera: Aphididae) in Three Tetraploid Switchgrass Populations

“…In wheat, accessions have been identified with each of the three categories of resistance to the Russian wheat aphid, Diuraphis noxia (Kurdjumov), with ten Dn genes controlling resistance to D. noxia [36,41]. Additionally, Hawley et al [15] and Miller et al [21] reported that the Dn4 gene displayed antixenosis, antibiosis, and tolerance categories to D. noxia. Importantly, resistance that incorporates two or more categories of resistance is a particularly useful trait that may help delay the development of virulence of new aphid biotypes [11,41].…”