Taxonomic relevance of petiole anatomical and micro-morphological characteristics of Clematis L. (Ranunculaceae) taxa from South Korea

We assessed the micro-morphological and anatomical structures of the petioles of 19 Clematis taxa from South Korea. The petiole surface features were observed with the help of stereomicroscopy and scanning electron microscopy, and the anatomical features are studied via microtomy and light microscopy. The results of this study showed that the presence/absence and abundance of trichomes, petiole cross-section outlines, upper surface wings and grooves, and the number of vascular bundles were useful for species discrimination in Clematis. Among the studied taxa, C. hexapetala was the only species with a glabrous petiole surface. Two types of trichomes were observed in the other 18 taxa: long, non-glandular and flagelliform trichomes and short, glandular capitate trichomes. We found four to six major vascular bundles and a maximum of eight interfascicular vascular bundles (C. heracleifolia and C. urticifolia) in the 19 taxa. A cluster analysis based on UPGMA identified six clusters with 18 nodes. Although the number of taxa investigated was limited, taxa from the sections Tubulosae, Viorna, and Astragene clustered with each other in the UPGMA phenogram due to the overall similarity of petiole features. Based on this observation, we can conclude that most of the petiole features are limited to the species level, and thus, the data obtained could be used as descriptive and/or diagnostic features for particular taxa, which may be useful for the investigation of problematic taxa in the genus.

Genetic structure in natural populations of Dacrydium elatum (Roxb.) Wall. (Podocarpaceae) in the Central Highlands of Vietnam inferred by Microsatellites

To provide a reference for the conservation and application of breeding parentallines resource of Dacrydium elatum (Roxb.). Genetic diversity and population structure of eighty individuals from four populations (Kon Tum, Gia Lai, Dak Lak and Lam Dong) in Central Highlands were evaluated using eight SSR markers. Based on the SSR data, 21 alleles were detected by eight SSR with high polymorphism. The genetic diversity of levels within the populations were moderately high (Ho = 0.555, He = 0.429). The average number of shannon information index were 0.618 and genetic differentiation among populations was low (Fst=0.097). The AMOVA revealed high genetic variation within individuals (87%) compared among populations (13%). The UPGMA phenogram showed that the results of molecular clustering largely agreed with the pedigree and geographic origin. Three populations (NL, KCR and BDNB) were clustered together and CYS population was separated. The maximum quantity ΔK was observed for K=2 in population structure analysis, indicating that the entire collection could be divided into two main groups of genes. This study can provide a theoretical basis for genetic resource management and varieties identification of D. elatum resources, and provide reference basis for breeding.

Leaf architecture and petiole anatomy of Philippine Dipterocarpus species (Dipterocarpaceae)

The study investigated the leaf architecture and petiole anatomy of eight Dipterocarpus (Dipterocarpaceae) species growing in Mount Makiling Forest Reserve (MMFR) in the Philippines to delineate the species, especially during their non-flowering phase. Leaf and petiole samples from MMFR were examined following the manual on leaf architecture studies. Freehand technique was used to examine the stomata and petiole characters. A UPGMA phenogram was then generated to determine the relationships among Dipterocarpus species using 26 leaf and petiole characters. The most useful characters to delineate Dipterocarpus species are the presence of trichomes, the arrangement of vascular bundles (medullary and outer vascular bundles), areolation, fimbrial vein, and leaf size. Other characters viz., the laminar ratio, blade class, laminar shape, base shape, margin type, and intersecondary, and layers and shape of parenchyma and collenchyma cells were useful as unifying characters. Therefore, certain characters of the leaf architecture and petiole anatomy may be used as taxonomic markers to delineate and correlate the Dipterocarpus species in the Philippines particularly during the nonflowering phase of the species. However, further investigations using samples from the wild populations of the species and molecular techniques may be done to elucidate the taxonomic use of the characters presented in this study. Bangladesh J. Plant Taxon. 27(1): 1-14, 2020 (June)

Isozymic variability in a Brazilian collection of annatto (Bixa orellana L.)

The objectives of this work were to optimize the isozyme electrophoresis technique for Bixa orellana, and use isozyme markers for a preliminary survey on the genetic variability in Brazilian annatto germplasm accessions. Collection consisted of seed samples from sixty open pollinated trees, representing two Northern and four Southern geographic provenances. The extraction, electrophoresis, and interpretation of annatto isozymes are described. Three out of the twenty-one identified isozyme loci were polymorphic in the collection. The percentage of polymorphic loci (P = 21.05) and the expected heterozygosity in annatto (H T = 0.064) were low, compared to other tropical woody species. A UPGMA phenogram, constructed with Nei's genetic distances, clearly separated the germplasm provenant from North and Central Brazil. Variability was significantly higher among the accessions from Maranhão. A sharp genetic differentiation was detected between accessions from Maranhão and Pará States, despite their geographical proximity. The distinctive isozyme polymorphism, observed in the accessions from Maranhão, together with reports on local morphological heterogeneity in annatto fruit shape, color, and pubescence, calls for more detailed genetic and taxonomic investigation.

Genetic variation among pathogens causing "Helminthosporium" diseases of rice, maize and wheat

Twenty isolates of four fungal species, agents of "Helminthosporium" diseases in cereals, were collected from different regions: nine Bipolarisoryzae isolated from rice (Oryza sativa), seven B.sorokiniana from wheat (Triticum aestivum), two B. maydis, and two Exserohilumturcicum from maize (Zea mays). The strains were compared by PCR-RFLP and RAPD analysis. Size polymorphism among the isolates in the ITS region comprising the 5.8 S rDNA indicated genetic differences among the isolates, while a UPGMA phenogram constructed after the digestion of this region with restriction enzymes showed inter- and intra-specific polymorphism. The RAPD profiles indicated an expressive level of polymorphism among different species, compared with a low level of polymorphism among isolates of the same species. A UPGMA phenogram grouped the isolates according to the species and their host plant. RAPD profiles did not reveal polymorphism that directly correlated climatic factors with geographic source of the isolates of B. sorokiniana, and B. oryzae. Teleomorphic species revealed high similarity with their correspondent anamorphs.

Phylogenetic Relationships in Actinidia as Revealed by RAPD Analysis

Phylogenetic relationships within the Actinidia were investigated using randomly amplified polymorphic DNA (RAPD) markers. DNAs from 40 taxa, including 31 species encompassing all four sections and four series of the traditional subdivisions within the genus, were amplified using 22 preselected 10-mer oligonucleotide primers. A total 204 DNA bands were scored across the 40 taxa, of which 188 (92%) were polymorphic. A wide range of genetic similarity was observed among the taxa (0.13 to 0.61). The average similarity between varieties of the same species was 0.54, and between different species was 0.28, respectively. Although the phylogenetic analysis revealed a clear indication that section Leiocarpae was a monophyletic group, subdivisions of the other three traditional sections were poorly supported. The UPGMA phenogram showed that the majority of the species clustered into geographic subgroups in accordance with their natural distribution (the Yangtzi River, southeastern China, southern China and southwestern China). The intrageneric subdivisions of Actinidia appeared to be difficult, but some subdivisions could be explained by the geographic distribution of the species, particularly for species of Liang's sections of Maculatae and Stellatae. The phylogenetic relationships among several species with previous taxonomic uncertainty are also discussed on the basis of the RAPD data. The results of this study supplement our previous understanding of the Actinidia taxonomy based solely on morphological characters.

Phenetic distinction between the dwarf yellow water-lilies: Nuphar microphylla and N. pumila (Nymphaeaceae)

Nuphar pumila (Timm) DC. and Nuphar microphylla (Pers.) Fern. are morphologically similar yellow water-lily species that are often regarded as conspecific or recognized as varieties of Nuphar lutea (L.) Sm. This phenetic study analyzes 18 features of vegetative, floral, and fruit morphology scored from North American populations of N. microphylla and Eurasian populations of N. pumila. Morphological similarities among specimens were assessed by univariate statistics, clustering by the unweighted pair group method using arithmetic averages (UPGMA), and ordination by principal components analyses. Means for 17 of the 18 quantitative variables differed significantly between operational taxonomic units (OTUs) of the two species, and an UPGMA phenogram provided good separation of OTUs. Principal components analysis also provided reasonable separation of OTUs, indicating leaf and fruit characters as strong distinguishing features. Multivariate analyses indicate two similar, yet distinct, morphological entities. When coupled with qualitative features, geographical barriers, and putative physiological barriers, morphometric data support the taxonomic recognition of two closely related species. Both species are most closely related to the Japanese endemic Nuphar japonica DC.Key words: Nuphar, Nymphaeaceae, water-lily, taxonomy, phenetics.