ISHS Acta Horticulturae 494: II International Symposium on Chestnut
GENETIC VARIATION AND POPULATION STRUCTURE OF THREE ENDEMIC CASTANEA SPECIES IN CHINA |
| Authors: | P. Lang, . |
| Keywords: | C. mollissima Bl., C. seguinii Dode., C. henryi Rehd.& Wils., population, allozyme, genetic diversity, genetic structure |
| DOI: | 10.17660/ActaHortic.1999.494.40 |
| Abstract:
Genetic variability in 30 populations of three endemic Castanea species (C. mollissima Bl., C. seguinii Dode. and C. henryi Rehd. and Wils.) in China was investigated using isoelectric focusing on thin-layer polyacrylamide slab gels at 20 loci coding for 12 enzyme systems. C. mollissima was found to possess significant higher values of genetic variability than that of the other two species. The percentage of polymorphic loci (P) and the expected heterozygosity (He) was 90.0% and 0.311 at the species level respectively, while P=84.7%, He=0.295 at population level, respectively. Comparison of the population genetic variability of C. mollissima in three regions of China, the populations from the Changjiang river valley, particularly from Shennongjia and surrounding areas, showed a markedly higher mean expected gene heterozygosity. Genetic relationships among populations and species were assessed by Nei's genetic identity (I) and standard genetic distance (D), suggesting that C. mollissima and C. seguinii have a closer relationship. Genetic differentiation between populations in C. mollissima, C. seguinii and C. henryi was 7.5%, 10.9% and 22.1%, respectively, and the gene flow rate (Nm) was 3.20, 2.05 and 0.88, respectively. Based on previous research, the results provided additional evidence that C. mollissima was the progenitor of Castanea and the Changjiang river valley, particularly Shennongjia area, was the center of the genetic diversity of genus Castanea. | |
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