Allozyme divergence and evolutionary relationships among Populus deltoides, P. nigra, and P. maximowiczii

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Om P. Rajora ◽  
Louis Zsuffa

Horizontal starch gel electrophoresis of enzymes was used to study genetic divergence among Populus deltoides Marsh. (section Aigeiros Duby, Salicaceae), P. nigra L. (section Aigeiros), and P. maximowiczii Henry (section Tacamahaca Spach.) at 37 to 40 allozyme loci coding for 12 enzyme systems in root tips. These three Populus species were genetically distinct from each other. Populus deltoides, P. nigra, and P. maximowiczii had mutually exclusive alleles at two loci, and each of these species had unique alleles at many loci. Certain allozyme loci were detected only in one or two of these species. Frequency distributions of allozyme loci were bimodal with respect to genetic identity for comparisons between any two species. The mean genetic distance was 0.36 ± 0.10 between P. deltoides and P. nigra, 0.39 ± 0.09 between P. deltoides and P. maximowiczii, and 0.34 ± 0.10 between P. nigra and P. maximowiczii. The enzyme electrophoretic evidence indicated a monophyletic origin of the three Populus species.Key words: poplars, genetic identity and divergence, allozymes, molecular evolution, phylogenetics.

1990 ◽  
Vol 68 (5) ◽  
pp. 990-998 ◽  
Author(s):  
Om P. Rajora

Horizontal starch gel electrophoresis of enzymes was used to compare the allelic constitution of individuals of Populus deltoides Marsh., P. nigra L., P. maximowiczii Henry, P. ×canadensis Moench, and F1 progeny of controlled crosses. Forty allozyme loci coding for 12 enzyme systems in root tips were observed. Populus deltoides, P. nigra, and P. maximowiczii were genetically distinct from each other. Each of these species had unique alleles at many loci, and one or two of these species also had some species-specific genes. Populus deltoides, P. nigra, and P. maximowiczii could be distinguished by mutually exclusive or unique alleles at any of the four allozyme loci Aco-2, Lap-1, Lap-2, and Pgi-2. Additionally, allozymes of Pgm-1, 6-Pgd-2, 6-Pgd-4, and 6-Pgd-5 could be used as markers to distinguish P. deltoides from P. nigra and P. maximowiczii, allozymes of Mdh-2, Per-3, Pgm-2, and Pgm-3 to distinguish P. nigra from P. deltoïdes and P. maximowiczii, and allozymes of Got-1, Got-4, and Pgi-1 to distinguish P. maximowiczii from P. deltoides and P. nigra. The observed marker allozyme genes and alleles can be effectively used for discriminating among the three Populus species and their interspecific hybrids, and identification and verification of paternity of progeny of single-pair and interspecific pollen-mix controlled crosses. Biochemical and molecular markers have significance in genetics, breeding, and systematics of these Populus species. Key words: Populus, allozymes, diagnostic genes and alleles, species and hybrid differentiation, enzyme electrophoresis.


Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 440-448 ◽  
Author(s):  
Om P. Rajora

The allelic constitution of 30 Populus deltoides Marsh, clones selected in Canada and United States was determined for 37 allozyme loci coding for 12 enzyme systems in root tips. The enzymes were assayed by horizontal starch gel electrophoresis. One common allele was found at each locus in all clones. The interclonal allozyme variability was controlled by 12 loci. The average proportion of heterozygous loci per clone was 4.7%. There were 23 unique multilocus genotypes among 30 clones. On average, unique genotypes differed from each other at 4.33 loci. Principal-component analysis of clonal genotypes at 12 polymorphic loci indicated 8 loci to be the most differentiating for the clones. The first three principal components accounted for 47.6% of the total variation in 12 polymorphic loci. The ordination and grouping of the clones on principal components 1, 2, and 3 portrayed clonal relationships. Clones from the same small nautral population at Cherry Beach, Ont., and five clones of P. deltoides var. occidentalis were in the same group. There was no separation of clones of two varieties, P. deltoides var. deltoides and P. deltoides var. occidentalis. These results and their usefulness were discussed with reference to identification, certification, registration, and relationships of clones.Key words: Populus deltoides Marsh., allozymes, multilocus genotypes, clone characterization, clonal relationships, poplars.


2014 ◽  
Vol 70 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Andrzej Lewandowski ◽  
Maciej Filipiak ◽  
Jarosław Burczyk

The genetic structure of silver fir (<em>Abies alba</em> Mill.) was investigated among 8 populations from Sudety Mts. and 2 additional populations from other parts of Poland. Nine enzyme systems controlled by 13 allozyme loci were analyzed using starch gel electrophoresis. The mean expected heterozygosity, ranging from 0.06 to 0.11 and was lower compared to that found in other conifers. The mean genetic distance among all silver fir populations was 0.005. The Sudeten group of populations appeared to be genetically different from the two populations from other parts of Poland, indicating that at least two different centers are responsible for the current distribution of allozyme polymorphism in the tested populations.


Author(s):  
Iain F. Wilson ◽  
Elizabeth M. Gosling ◽  
William Tapper

Eight samples of Littorina tenebrosa and L. saxatilis (Mollusca: Gastropoda) from Ireland and Britain, including pairs of each form from two locations in Ireland, were screened for genetic variation at 12 polymorphic enzyme loci using starch gel electrophoresis. Levels of polymorphism and heterozygosity were similar in L. tenebrosa and L. saxatilis, apart from a sample of L. tenebrosa from Britain which was less polymorphic than the Irish samples. No alleles were found to be unique to either form. Phylogenetic analysis using UPGMA showed that L. saxatilis and L. tenebrosa populations clustered as a monophyletic group. Nevertheless, the mean genetic distance between parapatric populations of L. saxatilis and L. tenebrosa (D=0.076) was similar to the mean for allopatric populations of either species (D=0.080). This indicates that there is a barrier to gene flow between the two forms Despite this, L. tenebrosa does not merit specific status since populations of this snail do not cluster as a distinct group, separate from L. saxatilis populations.


1987 ◽  
Vol 17 (9) ◽  
pp. 1134-1138 ◽  
Author(s):  
Jung O. Hyun ◽  
Om P. Rajora ◽  
Louis Zsuffa

Isoenzyme studies were conducted on root tips of 200 Populustremuloides clones selected from eight geographic regions (populations) along north–south and east–west transects in Ontario. Starch gel electrophoresis was used to assay crude enzyme extracts from young root rips of rooted suckers obtained from the clones sampled. A total of 15 isozyme loci coding for eight different enzyme systems were resolved. The mean of total gene diversity was 0.252. An average of 79% of the loci were polymorphic in any one population, with an average of 2.7 alleles per locus. More than 90% of the genetic variability could be attributed to within-population differentiation. A deficiency of observed heterozygotes was calculated for all populations studied. The fixation index averaged 0.462. The genetic distance estimates among populations had an overall mean of 0.103. There was no correlation between genetic and geographic distances. Results of this study suggest this species in its Ontario range is genetically variable and moderately differentiated.


1986 ◽  
Vol 28 (3) ◽  
pp. 476-482 ◽  
Author(s):  
O. P. Rajora ◽  
L. Zsuffa

Male gametophyte (pollen) isozyme profiles of P. deltoides, P. nigra and their hybrids, and of P. maximowiczii were compared with those of the sporophyte (roots). Fifteen enzyme systems were resolved by starch gel electrophoresis for each species and hybrid, and a total of 51 encoding genes were observed. In P. deltoides, P. nigra, P. deltoides × P. nigra, and P. maximowiczii, respectively, 74, 80, 74, and 76% of the structural genes coding for these enzymes in the sporophyte were also found to be expressed by the male gametophyte. Most of the genes tested were found to be expressed after meiosis, apparently transcribed and translated in the haploid genome.Key words: gene expression, gametophyte, sporophyte, Populus, isozymes.


1968 ◽  
Vol 10 (4) ◽  
pp. 961-967 ◽  
Author(s):  
A. A. Grunder

Three regions of serum esterase activity of chickens were differentiated by means of starch gel electrophoresis and appropriate stains. Regions I and II seemed to represent aliesterase while region III apparently represented a cholinesterase. The patterns of zones of region I were classified into three phenotypes named A, B, and AB and the hypothesis was proposed that these are controlled by two codominant alleles named EsA and AsB. The staining intensity of these esterase zones among adults was sex-associated in that the mean staining intensity of zones was greater in male than in female sera. Frequency of the EsB allele was 0.70, 0.76, and 0.85 in three meat lines.


Genome ◽  
1989 ◽  
Vol 32 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Om P. Rajora ◽  
Louis Zsuffa

The genotypes of 21 clones of 18 Populus × canadensis Moench cultivars ('Baden 431', 'Blanc du Poitou', 'Canada Blanc', 'DN44', 'Dorskamp 925', 'Eugenei', 'Gelrica', 'Grandis', 'Heidemij', 'I-55/56', 'I-132/56', 'I-262', 'Jacometti', 'Ostia', 'Regenerata', 'Robusta', 'Steckby', and 'Zurich 03/3') were determined for 31 allozyme loci coding for 9 enzyme systems in root tips. Horizontal starch gel electrophoresis was used to assay the enzymes. All clones had allozyme gene and allele contribution from both P. deltoides Marsh, and P. nigra L. The interclonal allozyme variability was controlled by nine loci. 'Canada Blanc' and 'Ostia' shared the same 31-locus genotypes, whereas each of the remaining 19 clones, including 3 clones of 'Robusta' and 2 clones of 'Jacometti', had unique multilocus genotypes. On average, unique genotypes differed from each other at 3.59 loci. Principal-component analysis of the clonal genotypes at 9 variable loci indicated 4 loci (Idh-2, Idh-3, Mdh-4, and Idh-1) to be the most discriminating among the clones. The first two principal components accounted for 48% of the total variance in the nine loci. Clones on the principal component analysis ordination (principal components 1 and 2) were separated into 3 groups; 14 belonged to one group and 5 to a second group. 'Blanc du Poitou' was widely separated from all others. 'Canada Blanc' and 'Steckby' showed the highest genetic interrelationships. Three 'Robusta' clones and two 'Jacometti' clones were in the same group., The interrelationships among the clones based on allozyme genotypes were in general agreement with their speculated origin and (or) morphology.Key words: Populus × canadensis, allozymes, multilocus genotypes, clone–cultivar identification, clone relationships.


2000 ◽  
Vol 23 (4) ◽  
pp. 809-813 ◽  
Author(s):  
Erasmo Renesto ◽  
Cláudio Henrique Zawadzki ◽  
Eloísa Revaldaves

The existence of reproductive isolation between two morphs of catfish, endemic to the Iguaçu River (Brazil), was examined by enzyme starch gel electrophoresis. Tissues of 19 catfish (Pimelodus ortmanni) and 15 of a similar morph (Pimelodus sp.), which differs from P. ortmanni by presenting larger and more scattered dusky spots on its skin, were analyzed. A Nei's (1978) genetic identity of 0.551 was determined by the analysis of 22 enzyme loci. The loci EST*1, EST*2, GDH*1, GPI*1, GPI*2, IDH*1, MDH*1, MDH*2, and PGM*1 were fixed for different alleles in each morph, that is, no heterozygote was found for these loci. The enzymatic patterns observed for the two morphs indicate both that the taxa are reproductively isolated and that they in fact represent separate species.


1981 ◽  
Vol 11 (3) ◽  
pp. 573-579 ◽  
Author(s):  
R. T. Eckert ◽  
R. J. Joly ◽  
D. B. Neale

Megagametophyte tissue from seeds of 35 clones of Pinusstrobus L. were subjected to horizontal starch gel electrophoresis. The resulting gels were tested for activity of 10 enzyme systems. Isozymes observed were under control of at least 17 loci. Direct evidence, based on segregation of allozymes in megagametophytes of heterozygous clones, is presented for nine loci in five systems (LAP, GPI, GOT, PGM, and AP). Three polymorphic loci were detected for LAP. No genetic variation was detected for IDH, ADH, GLY-3-PD, GDH, or 6 PDG.Five pairs of linked loci were detected by chi-square analyses of joint segregation. Twenty-five of 36 possible two-locus combinations among 18 clones were evaluated. Recombination estimates suggest relatively strong linkage between LAP1-LAP2 and GPI2-GOT1; weaker linkage between LAP2-GPI2 (based on one clone only); and weak linkage between LAP2-AP1 and GOT3-AP1.


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