Assessment of bulk segregant analysis and marker- assisted selection for economically important traits in sugarcane : SRDC final report BS138

Abstract

The main aim of this project was to assess the feasibility of bulk segregant analysis (BSA) and marker-assisted selection for important traits in sugarcane. The target trait for this feasibility study was rust resistance. Initially, crosses were successfully made between susceptible and resistant parents to produce two mapping populations. Unfortunately and surprisingly, we were not able to identify fully susceptible clones in four separate rust trials on the two populations. Poor rust development occurred in the first bench trial in 1996 at Meringa (including clones known to be susceptible), and the second trial in January 1997 was a total failure due to lack of rust development. The third rust resistance trial was conducted in Meringa in July 1997, but all of the clones in the mapping populations were resistant. The fourth rust trial on these two populations was completed at the start of 1998, and the results confirmed that all of the clones in these two initial mapping populations were resistant to common rust. Lack of segregation for rust resistance within progeny of sugarcane crosses had not been observed previously by sugarcane breeders in Meringa. This unexpected problem delayed the project as BSA could only proceed after a mapping population segregating for rust resistance had been identified.