Selection for Eldana saccharina Borer Resistance in Early Stages of Sugarcane Breeding in South Africa

摘要

Eldana saccharina (eldana) is the most wide-spread sugarcane borer in South Africa and causes losses estimated at US$90 million. Breeding for resistance started in 1980. The objectives of this study were to examine the potential of evaluating sugarcane families and parents by using data collected from the seedling stage (Stage I) and determine the potential of using logistic regression models in Stage II to enhance breeding for eldana resistance. Data were collected from Stage I trials (BML12 and FML13) at Bruyns Hill and Pongola research stations, respectively, and Stage II (BSL12 and SSL12) at Bruyns Hill and Glenside research stations, respectively. There were significant family effects for BML12 (P = 0.0029) and FML13 (P = 0.0003) indicating families with low eldana dame could be selected. Family variance for BML12 (P = 0.0144) and FML13 (P = 0.0878) were significant indicating large variability. Broad sense heritability of 0.52 (BML12) and 0.51 (FML13) indicated the effectiveness of selecting elite families. The predicted gains were 19.93% (BSL12) and 68.89% (FML13) indicating the value of family selection. The results showed significant female effects (BML12, P = 0.0017; FML13, P = 0.0041) indicating the dominance of maternal effects and suggested additive genetic control. Significant Female x Male interaction effect (FML13, P = 0.0442) suggested existence of non-additive genetic effects. Logistic regression analysis results showed significant (BSL12, P < 0.0001; SSL12, P = 0.0232) suggesting selecting for eldana was effective. Sensitivity analysis validated discriminating ability for eldana damage. Adopting family selection and logistic regression models would enhance breeding for eldana resistance.