Plant Genome IV Conference Plant Genome IV Conference
Introgression between Saccharum L. species and other related genera within the Saccharinae subtribe, such as Erianthus sect. Ripidium Henrard, is being attempted. Erianthus species, and E. arundinaceus (Retz.) Jeswiet in particular, represent a promising source of improved ratooning and vigour, drought and flooding tolerance, and Pachymetra resistance, although they are characterised by a higher fibre content and higher juice colour. Markers could be used to follow chromosomes during successive introgression generations. Specific repetitive sequences would be useful to tag specific or multiple chromosomes and to assess the occurrence of chromosome loss. A genomic library of E. arundinaceus was constructed, and after screening, five repetitive sequences specific for the Erianthus genus were isolated. A dot blot procedure, allowing a rapid screening of Saccharum x Erianthus progenies for true hybrids was developed using these sequences as probes. The distribution of these sequences in a population of 65 Erianthus individuals, representing 9 different species, was investigated. Their specificity for the Erianthus genus was tested against members of the Saccharum complex and related genera such as maize and sorghum. These sequences were sequenced and compared to others in the databases. The chromosome location of these sequences using in situ hybridisation technology is being investigated. The usefulness of these sequences to follow introgression of Erianthus chromosomes in intergeneric hybrids is discussed.