Diploid populations and progenies of controlled crosses of blueberry, Vaccinium section Cyanococcus, were analyzed by starch gel electrophoresis for nine enzyme systems, aconitase (ACO), aldolase (ALD), alcohol dehydrogenase (ADH), glyceraldehyde-3-phosphate dehydrogenase (G-3-PDH), isocitrate dehydrogenase (IDH), leucine aminopeptidase (LAP), malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6-PGD), and phosphoglucose isomerase (PGI). Allozyme variants indicated the existence of three alleles at Ace-1, Ald, G-3-pdh-2, and Mdh-2; four alleles at Mdh-3 and 6-Pgd-2; five alleles at Aco-2, Idh, Lap-1, and 6-Pgd-1; six alleles at Adh-2 and Pgm-2; and nine alleles at Pgi-2. In addition, a null allele was found at Lap-1. In the majority of progenies, the inheritance patterns for each of these loci were consistent with mendelian laws for single gene control. Forty-seven pairs of loci were tested for independent assortment revealing two linked pairs, Pgi-2/Lap-1 and Pgm-2/6-Pgd-2, which appeared to represent two independent linkage groups.
An extensive survey and discussion of Vaccinium section Cyanococcus A. Gray in North America by starch gel electrophoresis has revealed high levels of variability (Bruederle and Versa, 1989; Bruederle et al., 1991); 90% of the allozyme loci examined were polymorphic within the section. Inheritance studies, however, have been reported for only a few loci; Versa et al.(1988) presented evidence for mendelian inheritance at four loci among the enzyme systems malate dehydrogenase (EC 1.1. 1.37; MDH) phosphoglucose isomerase (EC 5.3. 1.9; PGI) 6-phosphogluconate dehydrogenase (EC 1.1. 1.44; 6-PGD), and isocitrate dehydrogenase (EC 1.1. 1.42; IDH); Krebs and Hancock (1989) reported tetrasomic inheritance at four loci among the enzyme systems MDH, PGI, 6-PGD, and aspartate aminotransferase (EC 2.6. 1.1). Evidence for the genetic basis of more isozyme phenotypes and knowledge of the linkage relationships among isozyme loci would be useful for future genetic and breeding behavior studies and provide information on linkage conservation. The Vaccinium section Cyanococcus karyotype consists of 12 metacentric or submetacentric chromosomes (Hall and Galletta, 1971) that will potentially result in the development of maps for 12 linkage units. The purpose of this paper is to report: i) inheritance patterns at the diploid level for nine of the isozyme loci governing the enzyme systems aconitase (EC 4.2. 1.3; ACO), alcohol dehydrogenase (EC 1.1. 1.1; ADH), aldolase (EC 4.1. 2.13; ALD), glyceraldehyde-3-phosphate dehydrogenase (EC 1.2. 1.9; G-3-PDH), leucine aminopeptidase (EC 3.4. 11.1; LAP) MDH, 6-PGD, and phosphoglucomutase (EC 2.7. 5.1; PGM);(ii) linkage relationships among 13 of the loci governing these enzyme systems as well as IDH and PGI; and (iii) allozyme variants observed at these loci in V. boreale Hall and Aalders, V. myrtilloides