Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 17, 1999
Publication Date: N/A
Technical Abstract: Progress was made in the following research areas: 1) nucleic acid-based disease diagnosis; 2) molecular marker-assisted breeding; and 3) sugarcane transformation. Polymerase chain reaction (PCR) protocols were developed for the identification and detection of leaf scald and ratoon stunting disease pathogens in infected sugarcane tissue. Each protocol utilizes specific primers located within the intergenic transcribed spacer of 16S- 23S ribosomal DNA. The PCR protocol for leaf scald amplifies a 288 bp DNA product only from Xanthomonas albilineans; and the PCR protocol for ratoon stunting disease amplifies a 438 bp DNA product only from Clavibacter xyli subsp. xyli (Cxx). In addition, a tissue-blot DNA hybridization assay was developed for the detection of Cxx in infected sugarcane stalks. Two reverse- transcription PCR protocols were adapted with modification to detect the yellow leaf syndrome luteovirus and sorghum mosaic virus in infected sugarcane plants. Several species-specific random amplified polymorphic DNA (RAPD) and PCR markers were identified. These included RAPD markers OPA10g (185 bp) for S. brevibarbe var. contortum, OPA10d (465 bp) for S. giganteum (cytotype 2n = 30), and PCR markers Eri3/Eri4 (540 bp) for Erianthus spp., Gig1/P2 (176 bp) for S. giganteum (all cytotypes, 2n = 30, 60, 90). We are also looking for markers that are specific for other related species of sugarcane including S. spontaneum. A sugarcane transformation project was initiated. Progress regarding these research initiatives will be discussed.