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SIMILAR UNSTABLE MUTATIONS IN THREE SPECIES OF GRACILARIA (RHODOPHYTA) 1
Author(s) -
Meer John P.,
Zhang Xuecheng
Publication year - 1988
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.1988.tb04234.x
Subject(s) - biology , reversion , mutant , wild type , mutation , phenotype , frond , gametophyte , gene , spore , gracilaria , genetics , botany , algae , pollen
Unstable mutants with similar variegated pigmentation were genetically characterized in the red algae. Gracilaria tikvahiae (McLachlan), G. foliifera (Forsk.) Børg. and. G. sjoestedtii (Kylin). All three mutants were green plants with flecks of red tissue where cells had reverted to wild type. The mutant green phenotypes were all recessive, and their genetic behavior in crosses indicated that each was the result of a single, unstable, nuclear gene. Wild‐type revertant tissue was stable one it arose. Revertant plants obtained from spores and revertant fronds taken from variegated plants could not be distinguished from the normal wild type, either phenotypically or genetically. Reversion to wild type occurred during all phases of the life cycle. In crosses between the mutants and wild type, most of the F 1 tetrasporophytes were heterozygous wild‐type plants, an observation consistent with the recessive nature of the mutations; however, a low frequency of homozygous unstable‐green F 1 tetrasporophytes was also obttained from these crosses. The molecular basis of neither the mutant instability, i.e. the reversion to wild type, nor of the process producing the unstable green F 1 tetrasporophytes can yet be deduced, but the phenotype of the plants and genetic results suggest the involvement of transposable genetic elements.