Genetic, breeding and environmental parameters for yellow sugarcane aphid (Sipha flava) damage in advanced South African sugarcane breeding populations

Abstract

Yellow sugarcane aphid (YSA), a native pest of temperate and subtropical regions in North America, has spread to many regions of the world including KwaZulu-Natal and Mpumalanga sugarcane growing regions of South Africa. Cultivar differences to YSA damage have been observed in Mpumalanga where high infestation levels occur. The objectives of this study were to determine genetic, breeding, and environmental parameters for YSA damage and implications on breeding for resistance. Data for YSA damage were collected from 12 genotype populations planted in Mpumalanga. There were significant (p < 0.0001) genotype effects indicating genetic variability. Significant (p < 0.01) environment effects showed that YSA damage in February was significantly (p < 0.05) higher than in December. The significant (p < 0.01) genotype by environment interaction indicated February as the best month to screen for YSA. Higher broad sense heritability (> 0.70) suggests selecting resistant genotypes would be effective. Data collected in February produced higher broad sense heritability (> 0.80) than in December (< 0.70) suggesting February as the preferred month to score for damage. The proportion of resistant genotypes was 16.5% (range 2–34%), indicating the presence of resistant in South African advanced genotype populations. Evaluation of released cultivars showed N36, N49 and N71 are resistant while N57 and N73 are susceptible.