Source: CropBiotech Update

Gene-controlling aphid resistance in soybean reported

The soybean aphid is a serious pest of the crop, and has caused millions of dollars in economic losses. Farmers controlled the pest by applying chemical insecticides, until scientists discovered that plants could be resistant to aphid infestation.

Scientists are now busy mapping the gene or genes involved in aphid resistance, and Curtis B. Hilla and colleagues of the University of Illinois are no different.

Their articles,
- “Soybean Aphid Resistance in Soybean Jackson Is Controlled by a Single Dominant Gene” and
“A Single Dominant Gene for Resistance to the Soybean Aphid in the Soybean Cultivar Dowling”
appear in the latest issue of Crop Science.

Researchers aimed to determine the inheritance of soybean aphid resistance in two cultivars, Jackson and Dowling. They crossed the cultivars with Loda and Williams, soybean cultivars susceptible to aphids. By testing parents and F2 plants for aphid susceptibility in the greenhouse, and then performing statistical tests to determine inheritance patterns, researchers traced the soybean aphid resistance trait to a single dominant gene.

The gene is Rag1 in Dowling, but as yet unknown in Jackson. Because there is no known genetic relationship between the two resistant cultivars, it is possible that the resistance gene found in Jackson is unique and distinct from the Rag1 found in Dowling. Since aphid resistance is controlled by only one gene in soybean, however, breeders will have an easier time converting existing susceptible cultivars to resistant cultivars using backcrossing procedures.

ABSTRACTS:
- http://dx.doi.org/10.2135/cropsci2005.11-0421
- http://dx.doi.org/10.2135/cropsci2005.11-0438