Isozyme Characters Research Articles

Phylogenetic position of Vicia montbretii and Lens species in relation to Vicia subgenus Cracca (Fabaceae): morphological and isozyme evidence

The Near East endemic vetch Vicia montbretii is a taxonomically controversial species because it has been also treated either as Ervum kotschyanum or Lens montbretii. The phylogenetic affinity and taxonomic treatment of Lens species in relation to Vicia has become debatable. We studied variation of morphological and isozyme characters in V. montbretii, Lens odemensis, L. orientalis and L. nigricans in comparison to 19 species of Vicia subgenus Cracca and three Lathyrus outgroup species in order to get evidence about their systematic and phylogenetic position. The cladistic analysis of morphology revealed that V. montbretii is tightly connected with Lens species and the Ervum group. The cladistic analysis of isozymes placed V. montbretii and the three Lens species in subgenus Cracca as divergent subclades. V. montbretii differs from the Lens species in ten isozymes out of 16 analysed. Vicia montbretii appears sister to Vicia sections Cracca, Panduratae and Pedunculatae, whereas the Lens subclade is linked to the subclade of Vicia sections Ervoides, Ervilia and Lenticula. The consistencies and differences between the morphological and molecular characters (isozymes plus DNA sequences) are discussed.

Keragaman Genetik Beberapa Genotipe Jarak Pagar (Jatropha curcas L.) Berdaya Hasil Tinggi Berdasarkan Karakter Morfologi, Agronomi, dan Isozim

<p>The interest in using Jatropha curcas L. from the<br />family Euphorbiaceae for the production of biofuel is rapidly<br />growing. The research objective was to determine genetic<br />variation of several high yielding physic nuts based on their<br />morphology, agronomy, and isozyme characters. The<br />research used Completely Randomized Design with three<br />replications. The treatment was consisted of 8 genotypes i.e.<br />IP-1A, IP-1M, IP-2P, Lombok Timur, Lombok Tengah,<br />Lombok Barat, Sumbawa, and Bima. Analysis of isozyme of<br />the eight genotypes was also conducted according to 5<br />enzyme systems, i.e. peroksidase, esterase, aspartat<br />aminotransferase, malat dehidrogenase, and alcohol<br />dehidrogenase. Observation was done on qualitative and<br />quantitative characters as well as banding pattern derivedisozymes.<br />The results showed that genetic variation was low<br />when based on qualitative characters and isozyme (0-25%)<br />but relatively high when based on selected quantitative<br />characters analysis (17-81%). Analysis of combined<br />qualitative, quantitative, and isozyme characters still gave<br />low genetic variation (6-33%). Based on the quantitative<br />characters at similarity coefficient of 46% the genotypes can<br />be devided into three clusters. Improved population<br />genotypes, i.e. IP-1A, IP-1M, and IP-2P were placed in 3<br />different clusters, while other genotypes from NTB area<br />were grouped in the same cluster. Therefore, selection<br />among population of the same ecotype based on agronomic<br />characters such as yield components, yield and oil content<br />was suitable in Jatropha improvement, especially when<br />genetic variation was low. Furthermore, introduction,<br />mutation and crossing are suggested to increase genetic<br />variation of current Jatropha collection.</p>

STUDIES OF SEED PROTEIN, ESTERASE ISOZYME AND SEED COAT SCAN ON SOME CULTIVATED SPECIES OF GENUS MINUSOPS (SAPOTACEAE) IN EGYPT

Electrophoretic profiles of native seed protein and esterase isozyme characters of four species of genus Mimusops have been revealed by PAGE. Seed coat scanning and numerical analysis of the results carried out. These species are M. laurifolia, M. elengi,M. zeyheri and M. coffra. The results of SEM on the surface seeds showed that, Seed ornamentation in Mimusops zeyheri differs than the rest species of the genus Mimusops by showing replicas of freeze on the their membrane surface. The results of seed protein and esterase isozyme characters indicated that delimitation of Mimusops zeyheri in a separated level, separation of two species of Mimusops coffra and Mimusops elengi in a separated group, in addition distinguishing of Mimusops laurifolia than other two species of Mimusops elengi and Mimusops coffra.

Polystichum lilianae sp. nov. (Dryopteridaceae) and its relationships to P. fournieri and P. turrialbae

Morphological, isozyme, and cytological analyses of the small, pale-scaled polystichums from oakdominated montane rain forests in Costa Rica and Mexico reveal the presence of a separable undescribed species endemic to the Cordillera de Talamanca of Costa Rica. The new taxon,Polystichum lilianae, is an allotetraploid hypothesized to have the sympatricP. turrialbae as one diploid progenitor based on isozyme characters. The isozyme and morphometric data also support the inclusion ofP. smithii, described from southern Mexico, inP. turrialbae, described from Costa Rica. The namePolystichum fournieri, formerly used for all of these plants, applies to species endemic to Oaxaca and Chiapas, Mexico. It is not a progenitor ofP. lilianae.

Genetic diversity of Rhizoctonia solani AG-3 from potato and tobacco in North Carolina

Anastomosis group 3 (AG-3) of Rhizoctonia solani (teleomorph = Thanatephorus cucumeris) is frequently associated with diseases of potato (AG-3 PT) and tobacco (AG-3 TB). Although isolates of R. solani AG-3 from these two Solanaceous hosts are somatically related based on anastomosis reaction and taxonomically related based on fatty acid, isozyme and DNA characters, considerable differences are evident in their biology, ecology, and epidemiology. However, genetic diversity among field populations of R. solani AG-3 PT and TB has not been documented. In this study, the genetic diversity of field populations of R. solani AG-3 PT and AG-3 TB in North Carolina was examined using somatic compatibility and amplified fragment length polymorphism (AFLP) criteria. A sample of 32 isolates from potato and 36 isolates from tobacco were paired in all possible combinations on PDA plus activated charcoal and examined for their resulting somatic interactions. Twenty-eight and eight distinct somatic compatibility groups (SCG) were identified in the AG-3 PT and AG-3 TB samples, respectively. AFLP analyses indicated that each of the 32 AG-3 PT isolates had a distinct AFLP phenotype, whereas 28 AFLP phenotypes were found among the 36 isolates of AG-3 TB. None of the AG-3 PT isolates were somatically compatible or shared a common AFLP phenotype with any AG-3 TB isolate. Clones (i.e., cases where two or more isolates were somatically compatible and shared the same AFLP phenotype) were identified only in the AG-3 TB population. Four clones from tobacco represented 22% of the total population. All eight SCG from tobacco were associated with more than one AFLP phenotype. Compatible somatic interactions between AG-3 PT isolates occurred only between certain isolates from the same field (two isolates in each of four different fields), and when this occurred AFLP phenotypes were similar but not identical.

Evolution of l-lactate dehydrogenase gene expression in non-avian reptiles

Isozyme characters, exclusive of allozymes (alleles), are potentially useful in phylogenetic investigations. Such data have been derived from the multilocus l -lactate dehydrogenase (LDH) enzyme system. Among non-avian reptiles, the classes of potential characters include (1) and number of loci encoding LDH, (2) heterotramer patterns, (3) tissue-specific patterns of gene expression, (4) tissue-specific posttranslational modification and (5) reversed relative mobility of the skeletal muscle (Ldh-A) and heart-predominating (Ldh-B) loci. The first three potential characters show variation among the species. However, because of the limited number of alternative states, and evolutionary pathways that variants can follow, it appears that such data will have limited applicability in phylogenetic investigations.

The use of isozyme characters in systematic studies

Abstract Several classes of isozyme characters are recognized including the number of genes that control a given enzyme system, intralocus and interlocus heteropolymer assembly, tissue-specific gene expression, developmental patterns of enzyme expression, and post-translational modification of gene products. All of these characters can be of value in systematic studies although few applications have been made to date; some of the more robust examples are recognized. Isozyme characters should be evaluated in terms of both their advantages and limitations. The level of universality at which they are used is group-specific. Tissue-specific gene expression data may be of the widest applicability in systematic studies.

The systematic value of creatine kinase expression in reptiles

Isozyme characters of creatine kinase, including the number of genes, the specificity of tissue expression, and the ability to form interlocus and intralocus heterodimers, were reevaluated for their potential for systematics applications among the reptiles. The gene number character has limited application because it is apomorphic only for chelid turtles. The intralocus heterodimer formation character has limited systematic value because of the infrequency of heterozygosity. Likewise, the interlocus heterodimer formation character has limited systematic value because of the infrequency of both Ck-A and Ck-C products being expressed in the same tissue. Differences in patterns of specificity of tissue expression hold the greatest potential for applications in reptilian systematics.

Gene expression in the desert tortoise, Gopherus agassizi; tissue sources and buffer optima for the gene products of 73 loci

The tissue distribution of products of 73 enzymatic loci (49 enzyme systems) was examined with eight different buffer systems to identify optimal electrophoretic conditions for allozymic and isozymic studies of the desert tortoise, Gopherus agassizi . Relative levels of enzyme activity are reported for extracts prepared from eye, brain, heart, muscle, liver, stomach, kidney, gonad, and blood. Given the paucity of comparative data, an assessment of the systematic utility of isozyme characters involving this species is limited. The greatest potential lies in the tissue distribution of some gene products and in the number of genes that control some enzyme systems, which differ when compared to that in somewhat distantly related chelid turtles. A restriction of asymmetrical heterotetramer assembly is noted in the L-lactate dehydrogenase system in G. agassizi , although this condition may be widespread among turtles.

The use of isozyme characters in systematic studies of turtles: preliminary data for Australian Chelids

In this study we explore how various treatments of a small isozyme data set may be used to generate phylogenetic hypotheses for comparison with the results of allozyme analysis involving some of the same taxa. The isozyme data were collected from various tissue samples representing eight species of four genera of Australian chelid turtles: Chelodina, Elseya, Elusor, and Emydura. Treatments of the allozyme components of these data employed a chord distance in a Distance Wagner analysis and particulate characters (‘‘locus-as-character’’) for a Wagner parsimony analysis. Treatments of a tissue expression data set included coding as presence—absent in a given tissue and as tissue arrays; a maximum parsimony analysis was used for both coded data sets. The resultant phylogenetic hypotheses were then compared with the current hypotheses of relationships among these turtles arising from morphological data as well as an independent and much larger allozyme data set. Our results support the conclusions of previous studies that the genus Elseya is polyphyletic. However the schema as to which species-level taxa in this genus are allied to the other chelid genera vary in our study with type of data and their encoding method. The relationship of Elseya dentata to other chelid turtles varied considerably with respect to di⁄erent data sets and di⁄erent means of coding and analysis. ( 1999 Published by Elsevier Science Ltd. All rights reserved.

Isozyme Variation in Echinocereus engelmannii var. munzii (Cacteceae)

Assessing the degree of evolutionary differentiation between a rare taxon and its relatives is critical from a biological perspective. Because funding and time are limited, conservation biologists need to set maintainance of truly unique pieces of biodiversity as a higher priority than maintenance of interesting populations of widespread species. Although many factors go into setting priorities, thorough assessment of evolutionary distinctiveness based on multiple lines of evidence is the most basic. We used isozyme characters to assess the distinctiveness of a purportedly rare taxon, Echinocereus engelmannii var. munzii (Munz’s hedgehog cactus), from other common varieties of the same species. We sampled at least 15 individuals from one population in each of the three mountain ranges where E. e. var. munzii is present within the United States plus three corresponding desert populations of a more common variety. To test for clinal variation between mountain and desert populations, we sampled three elevationally intermediate populations in the San Bernardino Mountains. We recognized a total of 104 band patterns for nine enzyme systems. All nine enzyme systems yielded polymorphic zymograms. Although we found substantial intrapopulation variability, no significant isozymic differentiation was apparent among any of the sampled populations. Lack of such differentiation implies that the effects of selection or drift have not been felt or detected in these populations. In terms of these enzyme systems Echinocereus engelmannii var. munzii is not distinct from other members of the species. Although there is no evidence of isozymic distinction, morphological evidence should be included in any decisions to submerge this taxon.

Enzyme electrophoretic studies on the Aphis fabae group (Hom., Aphididae)

Abstract: The taxa of the Aphis fabae group s.str. are morphologically difficult to separate or inseparable. Vertical starch gel electrophoresis of members of the Aphis fabae complex s.str. and s.l. was carried out to find specific isozymic characters. Analysis of the banding patterns of 17 genetic loci reveals that each of the 18 taxa investigated can be clearly identified. A biochemical key is presented.

Congruence of chloroplast DNA restriction site characters with morphological and isozyme data in Solanum sect. Lasiocarpa

Chloroplast DNA restriction site characters were analyzed cladistically in species of Solanum sect. Lasiocarpa (subg. Leptostemonum), and results were compared with previously published analyses of morphological and isozyme characters. Cladistic analysis of the chloroplast DNA restriction site characters resulted in a single tree in which two main clades were detected: one comprised three morphologically distinct lowland Amazonian species, and the other included the Andean and the two Asian species. Character congruence among the three data sets was assessed with a previously described index and with a permutation test derived from this index. Taxonomic congruence was evaluated with a measure modified from that of another researcher. The three assessments of congruence indicate that the chloroplast DNA and isozyme analyses are the most incongruent, but they differ as to their evaluation of relative (in)congruence for the other comparisons. Combining the three data sets resulted in two most parsimonious trees whose topologies incorporate elements from each of the separate analyses. The combined chloroplast DNA and morphological analyses support a previously proposed hypothesis that the two Asian species are sister taxa and of a single origin, rather than having originated separately from two distinct South American groups. Key words: Solanum, chloroplast DNA, congruence, combined data, cladistics.

UNIVARIATE AND MULTIVARIATE ANALYSES OF SHELL VARIABLES WITHIN THE GENUS COCHLICOPA (GASTROPODA: PULMONATA: COCHLICOPIDAE)

The following four shell variables were measured on Cochlicopa nitens (n = 150), C. lubricella (n = 205) and ‘C. lubricella’ (n = 545): shell height (‘SH’), shell diameter (‘SD’), diameter of the last whorl (‘DIW’), and diameter of the second last whorl (‘DslW’). As reported in the literature, C. lubrica and C. repentina were assumed to be concho-logically indistinguishable. Therefore, the data pool of ‘C. lubrica’ includes two nominal species. Univariate evaluations allow good separation of ‘C lubrica’ vs. C. nitens (with the variables ‘DslW’ and ‘DIW’), and of ‘C. lubrica’ vs. C. lubricella (with the variables‘SD’ and ‘DIW’). Variable ‘SH’ shows the highest overlap between the threetaxa. For each shell variable thresholds are given for a classification. A very effective tool to separate the groupsis canonical discriminant analysis of the shell variables. Large-shelled forms of C. lubricella should be given more attention. In some cases preliminary notes about important isozymic characters are also given.

An integrated study of morphological and isozyme patterns found within a worldwide collection of Phytophthora citrophthora and a redescription of the species

A worldwide collection of 77 isolates of Phytophthora citrophthora from 30 different host species was investigated for variation in morphology and isozyme patterns. All isolates produced non-caducous, papillate sporangia. Only those isolated from cacao ( Theobroma cacao ) in Brazil produced chlamydospores, whereas cacao isolates from Indonesia did not produce chlamydospores. Over 70% of the isolates were sterile; the remainder could be designated as the A2 mating type based on pairings with P. capsici , though P. citrophthora itself did not produce oospores. The species was separated into three distinct isozyme subgroups: CTR1 containing isolates from widely distributed geographical locations on a broad range of hosts, CTR2 composed exclusively of Brazilian isolates from cacao, and a new subgroup CTR3 consisting of Indonesian isolates also isolated from cacao. A total of 14 enzymes and 17 putative loci were used to compare the isolates and seven loci were polymorphic. Peptidase was diagnostic for CTR1, malate dehydrogenase (MDH1) for CTR2 while the migration patterns for both glucose-6-phosphate dehydrogenase and hexokinase (HEX2) differentiated CTR3. A redescription of R. citrophthora is presented based on all 77 isolates including physiological, morphological and isozyme characters that can assist identification.

Genetic constitution of germ cells in intervarietal and interspecific chimeras of Brassica induced by in-vitro grafting

The characteristics of intervarietal and interspecific chimeras synthesized by the graft-culture method were determined by morphology, anthocyanin pigmentation pattern, and crossing. In an intervarietal chimera between 'YR-ranpou' (green cabbage) and 'Ruby ball' (red cabbage) in Brassica oleracea, a segregation phenomenon was noted in which seeds giving rise to purple and green plants were both produced in a single capsule in F1 progeny from crosses of chimeras with YR ranpou, the anthocyanin-free graft partner type. The degrees of segregation varied, reflecting the structure of the chimeras. YR ranpou-dominant chimeras produced capsules in which seeds gave rise to green plants at a high frequency, while Ruby ball-dominant chimeras produced capsules in which seeds in one capsule gave rise to purple plants at a high frequency. Mixed chimeras produced capsules with green plants or purple plants more regularly than did other chimeral types. Furthermore, a chimeral type in which seeds gave rise to green and purple plants was found in 3.2% of the total crosses. Segregation patterns in the progenies corresponded with the chimeral types. Chlorophyll-deficient variation (resulting in variegation or the production of albino plants) was found at a frequency of 2.6%. These results show that chimeric tissues are actually in a mixed state and that either the ovary develops from more than two cells or else that variation occurs in the germ-cell layer. In interspecific chimeras between Ruby ball and Komatsuna (B. campestris) various types of chimeras generally showed low pollen fertility, few capsules, and low seed-setting. Progenies from selves (geitonogamy), open crosses and crosses with the two parental species produce a predominantly homogeneous genotype showing either the Ruby ball or the Komatsuna type. Only two crosses produced four interspecific hybrids which expressed variations in their morphological and isozymic characters.

Morphological and Macromolecular Characterization of Hypocrea schweinitzii and Its Trichoderma Anamorph

Morphological, cultural, and isozyme analyses were used to determine variation in the Trichoderma anamorph of Hypocrea schweinitzii, a presumably unequivocal species of Trichoderma, and to assess whether the anamorph of H. schweinitzii can be assigned to T. longibrachiatum, T. reesei or T. pseudokoningii. The results of these studies indicate that H. schweinitzii comprises at least three distinct and taxonomically separable holomorph taxa that coincide with the geographical origin of the collections. The name H. schweinitzii can be applied to Northern Hemisphere and H. jecorina to tropical American collections; while taxonomically distinct, no name was given to a Chinese collection. The holomorphs of H. schweinitzii, H. jecorina, and the Chinese collection showed little intraspecific variation in morphology of the teleomorph or anamorph, or in cultural and isozyme characters. They exhibited no more variation than was noted in the ex type cultures of the named Trichoderma species. None of the named Trichoderma species coincided with any of the Hypocrea species studied. It is concluded that Trichoderma species in general can be narrowly defined but that morphology alone might not suffice to allow the identification of species. The synonymy of T. reesei under T. longibrachiatum is not supported by morphological and cultural observations and by isozyme data and it is therefore not accepted.

An Analysis of the Phylogenetic Relationships of Fifteen Taxa of Family Amoebidae

Summary Phylogenetic relationships were determined for 15 taxa representing 4 genera of family Amoebidae. Focusing on 191 isozymic, morphological, physiological and ecological characters, it is established that these genera constitute a monophyletic group. Although intergeneric relationships are only tentative, intrageneric relationships indicate that Amoeba carolinensis is the most primitive and Amoeba proteus the most derived of the taxa constituting genus Amoeba. Amoeba borokensis is a sister taxon of A. proteus and Amoeba amazonas, and A. amazonas is a sister taxon of A. borokensis and A. carolinensis. It is postulated that the hypothetical ancestors of the 15 taxa are mononucleated with multinucleated taxa arising from 2 of these ancestors to form A. carolinensis and Chaos nobile.

Morphological and Isozyme Divergence in Gambelia (Scrophulariaceae): Species Delimitation and Biogeographic Relationships

To compare hypothesized species boundaries in Gambelia to patterns of differentiation inferred from morphology and isozymes, we examined nine populations for divergence at 22 isozyme loci and 29 OTU's/populations for morphological divergence using 20 characters. Thirteen quantitative and seven qualitative characters were analyzed using clustering (UPGMA) and ordination (PCA, CVA) methods. Placement of North American shrub snapdragons in Gambelia separate from southern hemisphere species (Galvezia s. str.) was supported by numerous qualitative morphological and genetic differences. Within Gambelia, the pattern of morphological and isozyme variation is most concordant with recognition of two species, G. speciosa and G. juncea, based on the phylogenetic species concept. Each species can be defined by several invariant and unique morphological and isozyme characters. Delimitation of infraspecific taxa in G. speciosa is unwarranted, because no consistent interpopulation differentiation was observed. Recognition of segregate species within the G. juncea complex of Baja California and Sonora also was not supported. No constant morphological differences were observed for either G. glabrata or G. rupicola. Biogeographic and systematic data support hypotheses that the California Island endemic G. speciosa is relictual, that disjunct Sonoran populations of G. juncea were established recently, and that populations of G. juncea from the Cape Region of Baja California have been isolated since the Holocene. Generic and specific delimitation among New World shrub snapdragons are problematic. At the generic level, Munz (1926), Munz and Keck (1959), and Pennell (unpubl. data) treat all New World species in Galvezia Dombey; Rothmaler (1943, 1954) places North American species in two genera (Gambelia Nuttall and Saccularia Kellogg) and South American species in Galvezia; whereas Sutton (1988), in the most recent revision, includes all North American species in Gambelia and the South American and Galapagos species in Galvezia. Delimitation of species is equally unresolved. Two (Munz 1926; Wiggins 1980) to four (Rothmaler 1943; Sutton 1988) North American species commonly are recognized; recent treatments delimit one to three South American species and a Galapagos endemic. Differing treatments of North American taxa primarily reflect disparities in taxonomic rank accorded to the morphological variants of Gambelia juncea (Bentham) Sutton s.l. The present study examines genetic and morphological divergence among North American taxa. The initial taxonomic organization follows Sutton (1988), who delimits four species without infraspecific taxa in Gambelia. The species occur on the California Islands of the southwestern U.S.A. and Mexico, coastal Sonora, and the offshore islands and peninsula of Baja California in Mexico (Fig. 1): G. speciosa Nuttall (southern California Islands), G. juncea (Sonora, Baja California), and two species recognized by Sutton from the Cape Region of Baja California Sur, G. rupicola (Brandegee) Sutton and G. glabrata (Brandegee) Sutton. All species are longlived shrubs with showy red corollas and occur on cliffs and in washes and canyons from sea level to 1500 m. Gambelia speciosa is an island endemic occurring in only a few, small populations on Santa Catalina, San Clemente, and Guadalupe islands. Although G. speciosa is placed alternately in the genera Galvezia, Antirrhinum L., and Maurandya Ortega, Gambelia speciosa has not been submerged in another species and infraspecific variants have not been described. Besides its insular distribution, G. speciosa is differentiated readily from all other shrub snapdragon species by a personate corolla (throat closed by an expanded palate). The other three species recognized by Sutton in Gambelia constitute the G. juncea complex, which is segregated by Rothmaler (1943) into Saccularia. Because of polymorphism in inflorescence pubescence, leaf size and shape, stem and leaf pubescence, and calyx segment shape, taxa in the G. juncea complex are treated vari-

The intergeneric hybrid origin ofPoa labradorica (Poaceae)

Phytogeographic, ecological, morphological, anatomical, cytological, isozyme, and endonuclease restriction site evidence is presented demonstrating thatPoa labradorica is of intergeneric hybrid origin betweenDupontia fisheri subsp.psilosantha (pistillate parent) andPoa eminens (staminate parent).Poa labradorica is endemic to recently deglaciated areas of northern Quebec and Labrador which are within the overlapping range of the putative parents. Incapable of sexual reproduction,P. labradorica dominates large areas of coastal marsh through vigorous production of rhizomes. Most morphological, anatomical, cytological, isozyme, and DNA characters studied inP. labradorica showed states intermediate or additive to those of the putative parents.