Identification of pummelo (Citrus grandis (L.) Osbeck) cultivars using isozyme electrophoresis.

One hundred and one pummelo plants representing eight different cultivars of pummelo were fingerprinted and evaluated for intra- and inter-varietal variability using five enzyme systems. Starch gel electrophoresis was used to analyse extracts from fresh young leaves collected from trees located in the provinces of Can Tho and Vinh Long. Isozymic analysis revealed that all cultivars are isozymically heterogeneous, and composed of two or more clones. A total of 26 clones were discriminated from eight cultivars. Unique combinations of isozymic variants of the five enzymes assayed identified 18 (69%) of the 26 clones. The remaining eight clones could be separated into four additional groups. Our results have proven the potential use of isozymic variability for cultivar identification and assessment of the uniformity or purity of a variety.