Greenhouse Testing of Transgenic Peanut for Resistance to Sclerotinia minor

Abstract

Abstract Fungal diseases of peanut, such as Sclerotinia blight caused by Sclerotinia minor Jagger, are responsible for increased production costs and yield losses of up to 50% for peanut producers in the Southwest, North Carolina, and Virginia. A few cultivars with moderate disease resistance, such as Southwest Runner, have been developed through traditional breeding practices. An urgent need exists for developing peanut cultivars that are resistant to the broad spectrum of fungal pathogens that pose a recurring threat to peanut health. Transgenic peanut plant lines containing anti-fungal genes have been produced from somatic embryos of the susceptible cultivar Okrun and tested under greenhouse conditions for resistance to S. minor by inoculation with a mycelial plug. Disease symptoms of lesion length and vascular collapse were recorded for 30 transgenic peanut lines, non-transgenic Okrun, and Southwest Runner. The reaction of the majority of transgenic peanut lines to S. minor infection was indistinguishable from that of the susceptible cultivar Okrun. However, three transgenic lines had a significant increase in resistance to S. minor as compared to Okrun, and one line demonstrated levels of resistance comparable to the moderately resistant cultivar Southwest Runner.