CHUNG, MYONG GI1* and REID G. PALMER2. 1Department of Biology, Gyeongsang National University, Jinju 660-701, Korea; 2USDA ARS CICGR and Departments of Agronomy and Zoology/Genetics, Iowa State University, Ames, IA 50011, U.S.A. - Evaluation of allozyme diversity in the USDA soybean germplasm collections from China.
Information on genetic diversity within and among provinces or regions
in the center of gene pool of crop species is essential for the
efficient utilization of plant genetic resource collections. We
evaluated the genetic variation in soybean cultivars Glycine
max within and among 19 provinces from China (4655 accessions from
the USDA Soybean Germplasm Collection) and screened 51 alleles on 19
polymorphic loci (eight enzyme systems). We found high levels of
allozyme diversity within provinces; mean percentage of polymorphic
loci, mean number of alleles per locus, and genetic diversity ranged
from 42.1%, 1.52, and 0.167 (prov. Guandong) to 94.8%, 2.53, and 0.298
(prov. Sichuan), respectively. Overall about 81% of the total
variation in the total samples is common to all provinces
(FST =0.192). An UPGMA phenogram based on Nei's
(1978) genetic distance revealed three groups which correspond to the
three regions, suggesting that historically human-mediated seed
dispersal in China has occurred longitudinally rather than
latitudinally. Crosses between each of these groups and crosses
between other gene pools could increase genetic variability in the
future. Since a significant correlation between sample size and
genetic diversity was evident, it may be necessary to obtain more
accessions to maintain diverse sources of gene pools in the USDA
Soybean Germplasm Collection.
Key words: allozymes, China, genetic diversity, Glycine max, soybean, USDA germplasm collection