Genetic variation at fifteen putative loci in eight enzyme systems (aconitase, alcohol dehydrogenase, aspartate aminotransferase, phosphoglucose isomerase, phosphoglucomutase, shikimate dehydrogenase and uridine diphosphoglucose pyrophosphorylase) was studied in nearly 500 plants from 20 taxa of the genus Actinidia by means of starch gel electrophoresis. Eighty-two putative isozyme alleles were identified by analysing polymorphism within and among species, segregation in progeny from controlled crosses of Actinidia chinensis genotypes, and differences in banding patterns between shoot tip and pollen extracts. Cytosolic phosphoglucose isomerase was found to be duplicated in at least one diploid species, Actinidia chinensis. An agglomerative cluster analysis conducted on a genetic dissimilarity matrix did not correspond well with current taxonomic subdivisions of the genus and indicated that relationships between some Actinidia taxa should be reconsidered. For the enzyme systems studied, we identified 34 alleles in Actinidin deliciosa var. chlorocarpa, 39 alleles in Actinidia deliciosa var. deliciosa and 35 alleles in Actinidia chinensis. Actinidia deliciosa, the kiwifruit, (2n = 6x) and Actinidia chinensis (2n = 2x) share 34 of 40 alleles, and are consequently thought to be by far the most closely related species. Our results are consistent with the hypothesis that Actinidia deliciosa was derived by polyploidization solely from Actinidia chinensis without any other Actinidia species being involved.
Isozyme polymorphism in the genus Actinidia and the origin of the kiwifruit genome
TESTOLIN, Raffaele;
1997-01-01
Abstract
Genetic variation at fifteen putative loci in eight enzyme systems (aconitase, alcohol dehydrogenase, aspartate aminotransferase, phosphoglucose isomerase, phosphoglucomutase, shikimate dehydrogenase and uridine diphosphoglucose pyrophosphorylase) was studied in nearly 500 plants from 20 taxa of the genus Actinidia by means of starch gel electrophoresis. Eighty-two putative isozyme alleles were identified by analysing polymorphism within and among species, segregation in progeny from controlled crosses of Actinidia chinensis genotypes, and differences in banding patterns between shoot tip and pollen extracts. Cytosolic phosphoglucose isomerase was found to be duplicated in at least one diploid species, Actinidia chinensis. An agglomerative cluster analysis conducted on a genetic dissimilarity matrix did not correspond well with current taxonomic subdivisions of the genus and indicated that relationships between some Actinidia taxa should be reconsidered. For the enzyme systems studied, we identified 34 alleles in Actinidin deliciosa var. chlorocarpa, 39 alleles in Actinidia deliciosa var. deliciosa and 35 alleles in Actinidia chinensis. Actinidia deliciosa, the kiwifruit, (2n = 6x) and Actinidia chinensis (2n = 2x) share 34 of 40 alleles, and are consequently thought to be by far the most closely related species. Our results are consistent with the hypothesis that Actinidia deliciosa was derived by polyploidization solely from Actinidia chinensis without any other Actinidia species being involved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
