Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2001
Publication Date: N/A
Citation: Interpretive Summary: The wild soybean is the ancestor of the cultivated soybean. There is no information on the relationships of geographical origin and diversity of wild soybean and little data on the relationships between soybean and wild soybean with similar and different origins. Using primitive soybean varieties and wild soybean from four provinces in China and procedures that measure variation at the DNA level, our data show that soybean and wild soybean are genetically distinct and that lines within each species that originate within a single province are more closely related than lines that originated from different provinces. Some DNA diversity found in wild soybean did not exist in cultivated soybean demonstrating the genetic bottleneck that occurs with domestication and the potential of wild soybean to contribute genetic variation that does not exist in cultivated soybean. There was also much greater genetic diversity in wild soybean than in soybean and wild soybean that had similar geographic origins could be very different genetically. Wild soybean and soybean from the same province were generally no more closely related than lines of different species from different provinces but the wild soybean from Heilongjiang province in northeast China were more closely related to soybean lines than were any of the other wild soybean. This research shows that origin can help predicate genetic relatedness within both soybean and wild soybean but there is much greater diversity among wild soybean even within small geographical areas. More wild soybean lines are needed to effectively sample the diversity that exists within that species and that the great genetic diversity in wild soybean could be exploited in breeding programs and in sampling and managing germplasm collections.
Technical Abstract: Wild soybean [Glycine soja (Sieb. and Zucc.)] is the ancestor of soybean [Glycine max (L.) Merr.] and is widely distributed in China, Japan, Korea, Taiwan, and eastern Russia. Use of more soybean introductions and G. soja lines in breeding programs to expand the genetic base of and incorporate specific traits for commercial soybean cultivars could be beneficial. This study was conducted to evaluate the genetic variation between and within Glycine species from different regions in China using RAPD markers. Eighty G. max and G. soja accessions from four Chinese provinces were surveyed with RAPDs. The results indicated that the genetic distance within the G. soja group was larger than that within the G. max group, but smaller than that between the G. max and G. soja groups. Twenty-three more polymorphic RAPD alleles were detected within the G. soja group than within the G. max group. Nine fragments were only present in G. soja lines. Cluster and principal component analyses can totally separate the G. max and G. soja groups based on RAPD data. The groups formed by cluster analyses generally reflected the geographical regions of origin. There was no genetic association between the origin of G. max lines and G. soja lines but the genetic distances between the G. soja lines from Heilongjiang and the G. max accessions from all other provinces were less than for the G. soja accessions from any other provinces. The results of this study could be used for exploiting the genetic diversity in the two species in breeding programs and in sampling and managing germplasm collections.