Open AccessGENETIC ANALYSIS OF ISOZYME VARIANTS IN DIPLOID AND TETRAPLOID POTATOES
Author(s) -
Carlos F. Quirós,
Neil A. McHale
Publication year - 1985
Publication title -
genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.792
H-Index - 246
eISSN - 1943-2631
pISSN - 0016-6731
DOI - 10.1093/genetics/111.1.131
Subject(s) - biology , mendelian inheritance , lycopersicon , ploidy , genetics , allele , isozyme , solanum , locus (genetics) , gene , solanum tuberosum , solanaceae , polyploid , botany , enzyme , biochemistry
Genetic segregations for six enzyme-coding genes were studied in diploid and tetraploid progenies obtained from various Solanum species. The loci identified are Prx-2, Prx-3, Prx-5, Mdh-1, Pgi-1 and Sdh-1. Prx-2 and Prx-3 were found to be linked; alleles at these loci segregated concomitantly in most of the diploid progenies. The putative homologous loci in tomato, Prx-2 and Prx-3, have also been reported to be linked, suggesting that this linkage block has been conserved since the divergence of Solanum and Lycopersicon. Several interspecific crosses between the species S. phureja and S. tuberosum, S. phureja and S. chacoense, and S. tuberosum and S. chacoense, yielded segregations for Prx-2 that deviated from expected Mendelian ratios. In these progenies unexpected phenotypes were commonly found, most likely due to posttranscriptional modification. Products of some of the alleles of Mdh-1 probably suffered posttranscriptional modifications, although most of their segregations fitted expected Mendelian ratios. The most extreme case of posttranscriptional modification was found in phenotypes involving allele Mdh-1(4). Instead of the expected heterodimers in the heterozygous individuals, a slowly migrating band close to the origin was observed in these phenotypes. Some of the accessions of the diploid species S. sparsipilum were found to have a unique zymogram for a second MDH zone of electrophoretic activity, MDH-2. We propose in this paper a common nomenclature for potato isozymes based on the nomenclature used for Capsicum and Lycopersicon.