Map-based chromosome and trait tagging in sugarcane using cytological and RFLP markers

Abstract

Sugarcane is a complex aneuploid, polyploid, interspecific hybrid. At the time that this project began, molecular mapping in sugarcane was in its infancy and was only being attempted in interspecific crosses or within the selfed progeny of a variety. Two objectives of this project were, therefore, to demonstrate that markers could be used in variety by variety crosses in sugarcane and that molecular marker maps could be constructed in such crosses. Using a variety of marker types, these objectives have been met as described below. The major aim of the project was to enable the Australian sugar industry to access overseas information on traits, markers and genome organisation in sugarcane and other grasses. This was to be achieved using two strategies. Firstly, other groups nationally and overseas have begun searching for markers linked to agronomic traits of interest and relevance to sugarcane. These markers, identified in sugarcane and related grasses such as sorghum and maize, might provide a more rapid means of identifying useful markers for the Australian sugarcane industry, as compared to searching for markers de novo, as had been done in all other sugarcane populations to date. The second strategy was to develop a framework map in an Australian sugarcane cross using these and other markers. This map could then be used as a means of both identifying new markers linked to traits of interest in sugarcane and of aligning Australian co-segregation groups with linkage groups, and the information contained within, identified in other maps of sugarcane and related grasses in other laboratories.