| Abstract: | The glutamate oxaloacetate transaminase isozymes (GOT) extractedfrom 125 biotypes of Citrus and its relatives, Fortunella, Poncirus and Microcitruswere analyzed using polyacrylamide gel electrophoresis to investigate the taxonomicrelationships among citrus plants. Besides all the isozymes reported before, two newbands were detected and designated their putative alleles B and C in GOT-l.Among pummelo cultivars wide variations were found. Most of the mandarinswere identical, having SS for GOI-1 and MM for GOT-2 except forZou-Pi-Gan and Yao-Gan, which both had FS at GOT-1 and might be hybrids. This finding suggests that all of the mandarins may have originated from acommon ancestor. Sour orange biotypes showed a considerable variation in GOTisozymes. Most of the sour oranges in China were assumed to be hybrids betweenpummelo and mandarin based on GOT isozyme patterns, but two biotypes,Xiao-Hong-Cheng and Zhu-lan, had FS at GOT-1 and MB at GOT-2, whichstrongly suggests that they be hybrids of pummelo and Ichang papeda because Ballele of GOT-2 occurs only in Ichang papeda and its close relatives Yuzu andIchang lemon. From this study Yuzu is assumed to be derived from hybridizationof Ichan, papeda and mandarin. |
