Use of isozyme phenotypes for rapid discrimination among sugarcane clones

Abstract

Verification of cultivar identity is essential in routine plant breeding and associated research. The current study aimed to determine if scoring of isozyme phenotypes resolved with starch gel electrophoresis would provide a cheap, useful method of identifying sugarcane clones. One hundred Saccharum spp. hybrid clones selected at random from the Bureau of Sugar Experiment Stations's (BSES1s) parental germplasm collection at Meringa were surveyed for 20 enzyme systems. Fully expanded leaf or non-chlorophyllic leaf spindle tissue of field grown plants was used. Three enzyme systems (alcohol dehydrogenase, peroxidase and phosphoglucomutase) jointly yielded 11 reliable, inter-clonally variable markers. Isozyme variability in the population sample surveyed was lower than had been observed in earlier studies of progenitor Saccharum spp. The remaining enzyme systems were invariant or could not be scored reliably. An average of 3-52 band differences per pair allowed separation of 97% of all possible pair-wise combinations. Complete discrimination of clones cannot be achieved with these markers, but they are reliable for checking identity of suspected mislabelled clones.