Rapid phenotypic assessment of bird cherry‐oat aphid resistance in winter wheat

Abstract

Rhopalosiphum padi L. causes significant damage to winter wheat (Triticum aestivum L.), even without obvious aboveground symptoms of injury. Our objectives were to develop a juvenile-plant bioassay for bird cherry-oat aphid (BCOA) resistance that allows rapid phenotypic differentiation. Central features of the bioassay include root and shoot weight measurements of 3-week-old seedlings produced in seed germination pouches, a 14-day aphid exposure period, and a non-infested control treatment to establish a baseline for expected biomass per genotype. Cultivars used in bioassay development were ÔIllinois RustproofÕ and ÔSkalaÕ, which showed smaller BCOA-induced reductions in biomass than the more susceptible genotypes, ÔPatrickÕ and ÔScout 66Õ. Mean reductions in root biomass were 48% for ÔPatrickÕ and ÔScout 66Õ, compared with 29% for ÔIllinois RustproofÕ and ÔSkalaÕ. This rapid and repeatable bioassay is extendable to large wheat collections and inbred line populations.

Genetics of Greenbug Resistance in Synthetic Hexaploid Wheat Derived Germplasm

“…Since the flats were grown side by side, the non-infested flats were treated with a 0.2% solution of Admire ® (Bayer, Imidacloprid @ 30.2%) 1 day before the infestation treatment was applied, with the objective to avoid aphid establishment and movement from the infested flats. This insecticide is a commercially available product in Mexico, and its active ingredient has been tested to assess the resistance to aphids in wheat (Dunn et al, 2007).…”

Virus Resistance in Cereals: Sources of Resistance, Genetics and Breeding

“…Resistance to WSMV and the virus vector (i.e., the wheat curl mite) has been identified and transferred into wheat from rye (Harvey et al., 1990, 1994; Wood et al., 1995; Thomas et al., 2004; Li et al., 2007b), Aegilops (Malik et al., 2003) and several grass species (Thomas and Whelan, 1991; Li et al., 2002). In contrast to barley in which only some limited vector resistance is known for aphids transmitting BYDV/CYDV (Hesler et al., 1999; Dunn et al., 2007), highly effective vector resistance has been detected in this pathosystem, e.g. cv.…”

Mapping resistance to the bird cherry-oat aphid and the greenbug in wheat using sequence-based genotyping

“…Infestations started when seedlings were at 2-3 leaf stage. Plants of treatment 2 were treated with the systemic insecticide Confidor WG ® (Bayer CropScience) at a dose of 3.5 % of active ingredient by pouring the solution in the soil (Dunn et al 2007). Fifteen days later, plants of both treatments were cut at the soil level and dried during 72 hours at 70°C.…”