GENETIC-POLYMORPHISM IN WILD AND CULTIVATED SIPHONOCHILUS-AETHIOPICUS(ZINGIBERACEAE)

Horizontal starch gel-electrophoresis was utilized to estimate genetic diversity within a natural population of wild ginger (Siphonochilus a ethiopicus) and individuals of the species cloned for commercial purpo ses. The aim of this study was to determine if electrophoresis is usef ul in studying genetic variation in S. aethiopicus. In the wild popula tion, 50 plants revealed genetic variation at 11 (50%) of the 22 enzym e coding loci studied. The percentage of polymorphic loci (P) was 50, a value of 1.55 (+/- 0.13) was obtained for the mean number of alleles per locus (A) and the average heterozygosity per locus (H) was calcul ated at 0.177 (+/- 0.044). These values were 4.55, 1.05 (+/- 0.05), an d 0.023 (+/- 0.023), respectively, fcr the cultivated clones. Allozyme data for the wild population is compared with that of two sources of cultivated specimens, showing that genetic fingerprinting of S. aethio picus clones can be achieved by using only 11 polymorphic loci and tha t the two cultivated clones probably originated from the same source. The exceptionally high allelic heterogeneity obtained for individuals (clonal polymorphism) may be due to the synergistic effects of vegetat ive and sexual reproduction. (C) 1997 Elsevier Science Ltd.