Li Similarity Coefficient Research Articles

Bamboo Diversity in Indrokilo Botanical Garden, Central Java

<p>The efforts of Bamboo conservation have been conducted by botanical gardens in Indonesia, including the Indrokilo Botanical Garden, Central Java. Scientific information regarding the bamboo collection of the Indrokilo Botanical Garden, however, is not yet available. This study aimed to determine the diversity of the species, as well as, to provide a synopsis and the similarity analysis of the bamboo species in the Indrokilo Botanical Garden. Exploration and collection of bamboo specimens have been carried out by the Indrokilo Botanical Garden. Processing and identification of the specimens were carried out at Herbarium Bogoriense. A total of 27 morphological characters were used for similarity analysis using the UPGMA method with Nei & Li similarity coefficients. The data were analyzed descriptively. There are seven species of bamboo in the Indrokilo Botanical Garden: Bambusa glaucophylla, B. lako, B. multiplex, B. vulgaris, Dendrocalamus sp., Guadua cf. angustifolia, and Schizostachyum sp. A synopsis of the bamboo species and their identification keys to the species were provided. Based on the similarity analysis, bamboo in the Indrokilo Botanical Garden consists of five groups at a similarity index of 70%. The diversity of bamboo species in the Indrokilo Botanical Garden is relatively low compared to some botanical gardens in Indonesia.</p>

Продуктивність часнику озимого в умовах Лівобережного Лісостепу України та молекулярно-генетичний поліморфізм досліджуваних сортів за ISSR локусами

In Ukraine, the area under garlic is increasing and as of 2020 amounted to 1,100 hectares, due to the high profitability of production and constant demand in both domestic and foreign markets. At the same time, the evaluation of existing and new varieties of winter garlic is important for further growth in yields of this important crop. The aim of the research is to assess the genetic diversity of the studied varieties of winter garlic by ISSR loci and to determine the most productive in the conditions of the Left Bank Forest-Steppe of Ukraine. Winter garlic varieties Duchess, Lyubasha and Hungarian (line 20-16) were used for the research. The highest level of marketable yield (14.1 t / ha) was obtained when growing winter garlic of Lyubasha. The Hungarian variety (Line 20-16) provided a yield of 12.9 t / ha, the Duchess variety 9.4 t / ha. The formation of winter garlic yield by 12.3 % depended on the characteristics of the variety, the influence of the growing season was 87.3 %. Agronomically stable (As ˃ 70 %) was the winter garlic variety Hungarian (Line 20-16) with As = 73.8 %. Based on the above studies, allelic formulas (molecular genetic passports) of winter garlic varieties Hungarian (Line 20-16), Lyubasha and Duchess were formed. In the studied varieties of winter garlic, several amplicons were found, unique within the study group. The UCC812725 and UBC 812902 loci were unique in the Duchess variety, and the UBC 812791 and UBC 842702 loci were unique in the Lyubasha variety. The calculated Nei–Li similarity coefficients indicate a significant genetic similarity of the studied varieties of winter garlic. The Lyubasha and Duchess varieties are genetically closer to each other than the Hungarian varieties (Line 20-16).

Assessment genetic diversity of einkorn genotypes (Triticum monococcum L.) by gliadin electrophoresis

The genetic diversity of gliadins in twenty two einkorn accessions preserved under long-term seed storage condition in the National gene bank of Bulgaria were evaluated, using acid polyacrylamide-gel electrophoresis (Acid-PAGE). In total, 64 polymorphic bands and 22 gliadin patterns were identified. Thirty four different mobility bands and 21 gliadin patterns were identified in the ω-gliadin zone, 12 bands and 16 patterns were noted in the γ-gliadins, 17 patterns and 12 mobility bands were found for β-gliadins and six bands with five different α -gliadin patterns were determined. The genetic diversity index (H) was the highest for ω-gliadins (0.950), followed by β-gliadins (0.924) and γ- (0.914), respectively and the lowest value was detected in α-gliadin patterns (0.120). Cluster analysis based on the UPGMA method and Nei and Li similarity coefficients classified all the genotypes into 3 main groups. No relationships between genetic diversity, geographic origin and the genotypes were observed. The results of cluster analysis justify the high level of genetic variation among investigated einkorn accessions.

Genetic diversity of Sterculia quadrifida in Kupang, Indonesia based on RAPD (Random Amplified Polymorphic DNA) markers

Abstract. Uslan, Pharmawat M. 2020. Genetic diversity of Sterculia quadrifida in Kupang, Indonesia based on RAPD (Random Amplified Polymorphic DNA) markers. Biodiversitas 21: 3407-3414. This study aims to determine the genetic diversity of Sterculia quadrifida R.Br. in Kupang based on RAPD markers. Samples of S. quadrifida were collected from the yard and community forest in Kupang City (Sub-districts of Oebobo, Kelapa Lima, Maulafa, and Alak) and mixed forest in the Kupang District (Sub-districts of Kupang Barat, Nekamese, Taebenu, and Fatuleu). DNA was isolated by the CTAB method and amplified by six RAPD primers (OPD-11, OPF-11, UBC-106, UBC-127, UBC-250, and OPB-04). The data were analyzed in the MVSP software using UPGMA method and Nei & Li similarity coefficient. Total of 131 DNA bands ranging from 250-1400 bp was obtained. Populations of S. quadrifida in Kupang were divided into two main clusters and 12 sub-clusters with. The highest genetic diversity was found in Kelapa Lima of 0.1050, while the lowest genetic diversity was found in S. quadrifida population in Fatuleu of 0.0305. The population of S. quadrifida in Kupang has high genetic diversity and also clustered based on their geographical distribution

Studies on the genetic polymorphism of courgetti (Cucurbita pepo L.) accessions by ISSR analysis

Purpose. Identify genetic polymorphism and divergence of C. pepo L. varieties and hybrids of different geographical origin using ISSR markers.Methods. ISSR analysis was used to evaluate the genetic polymorphism of 29 C. pepo L. varieties and hybrids of different origin. The similarity coefficient between the investigated courgetti accessions was calculated by the Nei – Li’s formula. Calculating coefficients of similarity and phylogenetic tree construction was performed with the Phylip-3.69 software package. The cluster analysis was performed by the Neighbor-joining method. The validity of the accessions grouping into clusters was tested by bootstrap analysis.Results. The use of 13 primers in the intermicrosatellite regions revealed 129 loci of courgetti DNA, among them 109 were polymorphic, 20 were monomorphic, 11 were unique to certain accessions. Electrophoregrams of the amplification products of the investigated accessions differed in the number and size of the amplicons. High DNA polymorphism of the investigated courgetti accessions was found, which ranged from 62,5% (primer UBC 810) to 100% (primers UBC 2, UBC 3, and UBC 846). The level of molecular genetic polymorphism of courgetti accessions varied from 55,8 to 63,6% in the 'Rimini' and 'Eight Ball' hybrids correspondingly. Low genetic divergence was determined between the C. pepo L. specimens, the Nei – Li similarity coefficient was 0,0005–0,0092. Using the cluster analysis, courgetti accessions were grouped into two clusters. The main criterion for clustering was the level of genetic divergence. The geographical origin of the accessions did not affect the peculiarities of their grouping.Conclusions. The results of the study of courgetti accessions of different geographical origin using ISSR analysis revealed high genetic polymorphism and little genetic divergence between the experimental accessions. Unique DNA fragments have been identified and can be used for the certification of relevant samples, as well as for the development of other molecular genetic markers. The obtained information may be useful for optimizing the courgetti breeding process and for further studies in the molecular genetics of this culture.

Molecular phylogeny of Chinese snakegourd (Trichosanthes kirilowiiMaxim) based on cytological and AFLP analyses

Amplified fragment length polymorphism (AFLP) marker and cytological analyses were employed to evaluate the genetic relationships and diversity of Chinese snakegourd. According to the cytological analyses, accessions 1, 2 and 3 were diploid (2n = 22), and accessions 4 to 12 were octaploid (2n = 88). Fourteen AFLP primer combinations generated a total of 645 reproducible loci among 12 Chinese snakegourd accessions studied, of which 628 loci were polymorphic with an average of 44.9 polymorphic bands per primer combination. Genetic similarities were obtained using Nei and Li similarity coefficients, and a dendrogram reflecting the relationship of 12 accessions was made using the unweighted pair-group method with arithmetic averages (UPGMA) clustering method. Based on the cluster analyses, 12 accessions were classified into two primary groups, in which group one included accessions 1, 2 and 3 that were diploid, and the other nine octaploid accessions formed group two. Analysis of molecular variance (AMOVA) re...

Genetic variability and relationships between and within grape cultivated varieties and wild species based on SRAP markers

Sequence-related amplified polymorphism (SRAP) markers were used to assess genetic relationships among 76 grape genotypes including Chinese indigenous and newly bred varieties, representatives of foreign grape varieties, and wild Vitis species. Nineteen informative primers were selected from 100 SRAP primer pairs due to their ability to produce clearly and repeatedly polymorphic and unambiguous bands among the varieties. A total of 228 bands were produced; 78.63% of them were polymorphic; the average polymorphism information content (PIC) is 0.76. Genetic relationships were obtained using Nei and Li similarity coefficients. Cluster analysis of SRAP markers through the unweighted pair-group method of arithmetic averages (UPGMA) analysis and principal coordinate analysis (PCoA) were largely consistent. The definition of clusters in the dendrogram and PCoA plot is the same and some degree of grouping by types of grape, ecogeographical origin, and taxonomic status of the varieties was revealed. Three main groups were found after cluster analysis, i.e., table grape of Vitis vinifera; table grape of Euro-America hybrid and wine grape of V. vinifera; wild Vitis species. Groupings indicated a divergence between the table and wine-type varieties of V. vinifera. The results showed that the wild Vitis species that originated from America and China could be clearly differentiated and Vitis hancockii is the most distant from the others of Asian Vitis species. The results also indicated that SRAP markers are informative and could distinguish bud sports of grape. The present analysis revealed that Chinese cultivated and wild grape germplasm are highly variable and have abundant genetic diversity.

Sequence-related amplified polymorphism analysis of tree peony (Paeonia suffruticosa Andrews) cultivars with different flower colours

SummarySequence-related amplified polymorphism (SRAP) was used to examine genetic relatedness and genetic diversity in 16 tree peony (Paeonia suffruticosa Andrews) cultivars having different flower colours. Twenty pairs of primers generated a total of 245 scorable PCR fragments among the 16 cultivars of tree peony, of which 175 bands (71.4%) were polymorphic. Genetic relationships were obtained using Nei and Li similarity coefficients. Cluster analyses of SRAP markers using the unweighted pair-group method of arithmetic averages (UPGMA) analysis, as well as Dollo and polymorphism parsimony analyses, were largely consistent. All revealed similar genetic relationships among the 16 tree peony cultivars having different flower colours. Groupings indicated that the division of cultivars was based largely on flower colour. Three main Groups were found after cluster analyses of the 16 cultivars based on SRAP markers. Cultivars with specific flower colours always grouped together. Estimates of genetic relationships and relatedness reflected the genetic diversity in flower colour in tree peony as a whole. The results also indicated that SRAP markers are informative and can provide new insights for genetic research in tree peony.

Assessing Morphological and Genetic Variation in Annatto (Bixa orellana L.) by Sequence-related Amplified Polymorphism and Cluster Analysis

Annatto (Bixa orellana L.) is the sole source of bixin, a seed-specific red apocarotenoid pigment used worldwide. Genetic improvement of annatto has focused on increasing bixin content as well as fostering traits that favor higher content such as pod indehiscence and flower color, among others. Eighty-seven samples collected from two separate important agricultural regions of the southeast of Mexico were characterized morphologically and analyzed genetically for the first time. The sequence-related amplified polymorphism was used for genetic analysis. Two-step cluster analysis of the individuals based on morphological traits produced three groups: one containing individuals with desired morphological characteristics and two others with complementary traits. Like the morphological analysis, the genetic analysis indicated high genetic variation, although the dendrogram based on Nei and Li's similarity coefficient showed them to be dispersed by collection site. However, calculated similarity index values indicated all individuals exhibited high genetic variation. The results are an important advance toward a more effective genetic improvement of annatto because crosses between the different morphological and/or genetic groups described here have the potential to produce a recombination of desired traits in hybrid offspring.

Assessment of Genetic Variation Within Indian Mustard (Brassica juncea) Germplasm Using Random Amplified Polymorphic DNA Markers

Genetic diversity among 45 Indian mustard (Brassica juncea L.) genotypes comprising 37 germplasm collections, five advance breeding lines and three improved cultivars was investigated at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Fifteen primers used generated a total of 92 RAPD fragments, of which 81 (88%) were polymorphic. Of these, 13 were unique to accession 'Pak85559'. Each primer produced four to nine amplified products with an average of 6.13 bands per primer. Based on pairwise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were calculated to evaluate the relationships among the accessions. Pairwise similarity indices were higher among the oilseed accessions and cultivars showing narrow ranges of 0.77-0.99. An unweighted pair-group method with arithmetic averages cluster analysis based on these genetic similarities placed most of the collections and oilseed cultivars close to each other, showing a low level of polymorphism between the accessions used. However, the clusters formed by oilseed collections and cultivars were comparatively distinct from that of advanced breeding lines. Genetically, all of the accessions were classified into a few major groups and a number of individual accessions. Advanced breeding lines were relatively divergent from the rest of the accessions and formed independent clusters. Clustering of the accessions did not show any pattern of association between the RAPD markers and the collection sites. A low level of genetic variability of oilseed mustard was attributed to the selection for similar traits and horticultural uses. Perhaps close parentage of these accessions further contributed towards their little diversity. The study demonstrated that RAPD is a simple and fast technique to compare the genetic relationship and pattern of variation among the gene pool of this crop.

AFLP-based genetic diversity assessment among Chinese vegetable mustards (Brassica juncea (L.) Czern.)

Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic relationships and diversities of Chinese vegetable mustards. Fourteen pairs of primers generated a total of 366 scorable fragments among 16 accessions of Brassica juncea studied, of which 296 bands were polymorphic with an average of 21.1% polymorphic bands per primer combination. Genetic similarities were obtained using Nei and Li similarity coefficients, and a dendrogram of the 16 accessions was made by UPGMA clustering method. The Nei and Li Similarity coefficient value ranged from 0.63 to 0.88. This result indicated that the 16 accessions of B. juncea possessed high level genetic variations. The cluster analysis showed that the vegetable mustards could be grouped into two main groups and some minor rami, which was partially in accordance with the traditional classification that based on different edible organs of vegetable mustards. The incongruity between morphological and molecular classification might be attributed to the high selection pressure during domestication of Chinese vegetable mustards, producing some accessions with similar genetic backgrounds evolving into abundant morphological variations. The great diversification among Chinese vegetable mustards not only provides an excellent object for molecular evolution research of B. juncea but also is of great value for widening the genetic basis of breeding programs and breeding materials selection. Besides, our study also indicates that AFLP are informative and can provide significant insights for genetic diversity research in B. juncea.

Genetic structure and spatial distribution of the mycoparasite Sphaerellopsis filum on Melampsora larici‐epitea in a short‐rotation coppice willow planting

AFLP analysis was used to examine the genetic structure of the mycoparasite Sphaerellopsis filum on willow rust Melampsora larici‐epitea using two sets of samples of a willow clone in a short‐rotation coppice planting. The first set was collected from a plot (short strip) in 1998, 1999 and 2000 and the second from another plot (long strip) in 2000. In all, 228 S. filum isolates were typed, 139 AFLP loci scored and 54 AFLP genotypes identified. In the short strip, genotypes sampled in 1998 were no longer detected in subsequent years and genotype diversity fluctuated (0·25–0·68) over the years, indicating that migration had a major impact on the genotype structure. Two distinct groups (average Nei and Li's similarity coefficient between the groups = 0·047) were identified. The group B genotypes were sampled only in 2000. Within the groups, the average similarities were > 0·96. Both the index of association test and the parsimony tree length permutation test suggest that there was a significant clonality in group A while recombination cannot be ruled out in group B. Localized clusters of AFLP genotypes were detected using the software SaTScan that is based on the spatial scan statistic. Possible mechanisms involved in the spread of S. filum in willow coppice plantations are discussed.

Isolation and characterization of microsatellite markers for analysis of molecular variation in the medicinal plant Madagascar periwinkle ( Catharanthus roseus (L.) G. Don)

Catharanthus roseus (L.) G. Don, commonly known as Madagascar periwinkle, is a plant of great medicinal value. In this study microsatellite markers were developed and utilized for analysis of genetic diversity in C. roseus. In order to isolate microsatellite sequences, two small insert genomic libraries of C. roseus cv. Nirmal were constructed and screened with CA, CT, GC and GCG oligonucleotide repeats. Sixty-five microsatellite motifs were identified, from which 38 functional STMS primer pairs were designed and validated. Out of these, 24 STMS markers were used to evaluate the genetic polymorphism in 37 genotypes, which comprised of 32 accessions of C. roseus, a single accession each of two related species ( C. trichophyllus and C. pusillus) and one accession each of three related genera ( Vinca minor, Thevetia peruviana and Nerium indicum). The 24 STMS markers detected 26 loci with two markers amplifying more than one locus. A total of 124 alleles were amplified in the 37 genotypes ranging from 2 to 10 alleles with an average of 4.76 alleles per locus. The high average expected heterozygosity ( H E) value of 0.56 and observed heterozygosity ( H O) value of 0.52 established the efficiency of the STMS markers for discriminating the C. roseus genotypes. Nei and Li's similarity coefficients were calculated and a UPGMA-based dendrogram was constructed which clearly distinguished all genotypes except two pairs. Sequence analysis of the length variant alleles at three STMS loci revealed that the variation in the copy number of repeat motifs was the major source of length polymorphism within C. roseus. However, isolated point mutations and indels in the microsatellite flanking regions (MFRs) of homologus loci from other species also contributed to size homoplasy and allelic size variation. This study is the first report of microsatellite development and utilization in C. roseus, providing significant insights into its genome structure and organization.

Estimation of genetic diversity in varieties of Mucuna pruriens using RAPD

Genetic diversity was estimated in 13 accessions of the otherwise self pollinated Mucuna pruriens (L.) DC. (velvetbean) comprising varieties pruriens and utilis collected from tropical humid forest using 15 RAPD primers. Similarity index value of 0.68 based on Nei and Li's similarity coefficient indicated high degree of genetic variability. Analysis of various genetic diversity indices like total heterozygosity, Nei's gene diversity, percentage of polymorphic loci, expected and observed number of alleles and Shannon index strongly suggests that variety pruriens is genetically more diverse than variety utilis. Chemical analysis with respect to 3,4-dihydroxy-L-phenylalanine (L-DOPA) content showed uniform distribution. Cluster analysis showed grouping of accessions into two major clusters and tendency of accessions of variety pruriens to group according to their geographical locations. Bootstrap analysis confirmed the robustness of the phenogram. The putative hybrid MMP6 with relatively low similarity value index and low L-DOPA content was promising as food or fodder.

Genetic Diversity of Traditional Chinese Mustard Crops Brassica juncea as Revealed by Phenotypic differences and RAPD Markers

This investigation was aimed at exploring the genetic diversity among nine typical accessions of Chinese mustard crops using random amplified polymorphic DNA (RAPD) markers and morphological comparison. Totally, 111 reproducible DNA bands were generated by 16 arbitrary primers, of which 91 bands were proved to be polymorphic. Based on pair-wise comparisons of the amplified bands, genetic similarities were obtained using Nei & Li's similarity coefficients and a dendrogram reflecting their relationships was made using the unweighted pair–group method with arithmetic averages (UPGMA). The result of cluster analysis indicated that the nine accessions were capable of being classified into two primary groups, one including accession 2 with expanded root (root mustard), accession 3 with entirely expanded whole stem (long-stem mustard), accession 6 with edible leaves (leaf mustard), accession 8 with edible seed stalk (seed stalk mustard) and another one including accession 4 with expanded basal stem (short-stem mustard), accession 5 with bulgy petiole (leafy bulgy mustard), and accession 9 with mustard-rich seed (seed mustard). Besides, accession 1 with expanded root (root mustard) and accession 7 with edible leaves and seed stalk (seed stalk mustard) were independent of other accessions in the dendrogram. Additionally, by cluster analysis based on highly reproducible RAPD markers, the accessions with similar edible parts of leaves or roots were not actually in the same phylogenetic groups. This implied that they were probably derived from different geographical origins with dissimilar genetic background and possessed higher genetic diversification. Furthermore, the results indicated that the traditional method for classifying Chinese mustard crops was not much reliable as it was largely dependent on phenotypic behaviors. Meanwhile, the phenotypic differences among individuals did not necessarily mean they must have sharp difference in genetic background as they met in the same group. Undoubtedly, these results aforementioned make this crop quite interesting to researchers for further investigating the molecular evolution of this special AABB group.

Identification of Prosopis juliflora and Prosopis pallida Accessions Using Molecular Markers

There has been much taxonomic confusion over the identification of Prosopis species, especially where introduced. Prosopis juliflora is the most widespread species in the arid and semi-arid tropics, although it has been confused with other species, particularly the closely related Prosopis pallida. In this study, RAPDs markers were used for the first time to distinguish between these species. Eighteen primers were used in amplification reactions, which yielded an average of 120 bands per accession. A dendrogram showing genetic similarities among accessions was constructed using UPGMA cluster analysis and the Nei and Li similarity coefficient. The genetic similarity observed between P. juliflora and P. pallida is similar to the value in sympatric Prosopis species in North America, and reconsideration of the series rank in section Algarobia is suggested. Species-specific markers confirmed that material in Burkina Faso is P. juliflora, but suggested that material collected in Brazil, Cape Verde and Senegal is P. pallida, whereas this has previously been identified as P. juliflora.

Genetic diversity analysis in Boerhavia diffusa L. of different geographic locations in India using RAPD markers

Boerhavia diffusa is extensively used in herbal medicines as well as in the Ayurvedic system, because it contains a set of clinically important compounds. In the present study, the genetic variability in Boerhavia diffusa between accessions of different geographical origin within the Indian territory is assessed through random amplified polymorphic DNA (RAPD) markers. Twenty-eight accessions of Boerhavia were screened with eighteen primers of which nine were found to be the most informative. The degree of polymorphism was found to be high in accessions collected from different places of Uttar Pradesh (Set II) in comparison to other states of India (Set I). A relatively lower level of polymorphism was recorded in accessions collected from diverse locations around Lucknow (Set III). Accessions from neighbouring geographical regions exhibited more similarity than those from distant regions (as revealed by the set I analysis). Certain diagnostic markers may be correlated with morphological character(s) such as plant type. BDL appeared most distinct and divergent from the rest of the accessions and the BDJ plant in set II also showed least similarity estimate. Fragments of 5.62 Kb and 4.47 Kb with primer GN59 was found to be unique for BDP and BD2 having ovate leaf character, whereas ovoid leaf genotype exhibited 0.79 Kb (GN34 primer) fragment. Similarly a unique band type (0.35 Kb) with primer GN83 was present in BDL and BD1 that share light pink flower. Jaccard's, and Nei and Li similarity coefficient values amongst the accessions were in the range of 0.22 to 0.89 and 0.33 to 0.93, respectively. Association of RAPD markers with the leaf characteristics, flower colour as well as with geographical locations has been made. This shows that RAPD markers are also useful for the study of genetic structure of Boerhavia populations.

Genetic Variation in Melampsora Larici-epitea on Biomass willows Assessed using AFLP

Five pathotypes belonging to formae speciales larici-epitea typica (LET), larici-retusae (LR) and larici-daphnoides (LD) of Melampsora larici-epitea were examined using amplified fragment length polymorphism (AFLP). Of 213 AFLP markers scored, several were found to be exclusive to different formae speciales. The dendrogram placed the five pathotypes into distinct groups. Within pathotypes, average Nei & Li's similarity coefficients were calculated as 0.71–0.85. The similarities were 0.66–0.72 among the three pathotypes within LET and 0.34–0.44 between pathotypes belonging to different formae speciales. When assessed using the Shannon index, the diversity within locations was estimated as 0.55–0.59, greater than that found within pathotypes (0.24–0.42). The average per-locus diversity was 0.37 among the pathotypes and 0.11 among the locations. When the data from both LET and LR isolates were examined using AMOVA, the majority of the variation (70.85%) was attributed to among pathotypes within location. When only LET types were included, approximately half of the variation was partitioned to among pathotypes within location and the other half to among the isolates within collection. It appears that the degree of differentiation of LET4 on S. × mollissima between Loughgall and Long Ashton sites has decreased markedly since 1992, when it was first detected.

Analysis of genetic diversity in Cassia brewsteri with randomly amplified DNA fingerprints (RAFs)

Genetic diversity in Cassia brewsteri (F.Muell.) F.Muell. ex Benth. was assessed with Randomly Amplified DNA Fingerprints (RAFs). Thirty accessions of C. brewsteri collected from throughout its natural distribution were analysed with three random decamer primers, along with three accessions of C. tomentella (Benth.) Domin and a single accession of each of C. queenslandica C.T.White and C. marksiana (F.M.Bailey) Domin. The three primers yielded a reproducible amplification profile of 265 scorable polymorphic fragments for the 35 accessions. These molecular markers were used to calculate Nei and Li similarity coefficients between each pair of individuals. A matrix of dissimilarity of each pair of individuals was examined by multidimensional scaling (MDS). The analysis supports the division of C. brewsteri into two subspecies and the suggestion that intergradation ofC. brewsteri and C. tomentella can occur where the distributions of these species meet.

AFLP evidence of the distinctive patterns of life-cycle in two forms of Melampsora rust on Salix viminalis

Amplified fragment length polymorphism (AFLP) was used to examine genetic variation in two forms of Melampsora rust on Salix viminalis , the ‘stem-infecting form’ (SIF) and the f. sp. larici-epitea typica (LET) of M. epitea. A simple two-tube method was used to obtain genomic DNA suitable for AFLP. Eleven SIF and 26 LET isolates from the UK were tested using two primer combinations. Of the 215 AFLP markers scored, 93% were polymorphic. AFLP profiles were distinct between SIF and LET (Nei & Li's similarity coefficients between SIF and LET isolates = 22-35%). Within SIF, AFLP patterns were very similar (similarity > 98.9%), indicating that SIF is an asexual population and may have a clonal lineage. Within LET, similarities were > 69%. LET isolates collected from a site at Long Ashton in 1991-1993 were closely related and, therefore, may have come from the same local source. Similarity data from AFLP were in good agreement (Spearman's rank correlation = 0.85) with that of RAPD when both SIF and LET isolates were included, but the correlation was less obvious (= 0.49) when only LET isolates were included. Identical banding patterns were obtained when AFLP was performed using either a Perkin-Elmer 480 or a Perkin-Elmer 9700 Thermocyclers, each programmed with a different PCR profile.