Search

Traditional hop (Humulus lupulus L.) cultivars have been used in the brewing industry for a long time. Globally, about ten new breeding lines were released to the market in each decade from ~1970 to 1999. Since 2006, the rate of release of new cultivars has increased tenfold. It is, therefore, important to identify their genotype and origin. Molecular genetic methods based on DNA are the most appropriate technology for this purpose. Recently, we developed an efficient marker system for the authenticity control of hop genotypes based on expressed sequence tag-simple sequence repeats (EST-SSR). In the present study, we enlarged the previously established EST-SSR set with 27 new polymorphic markers and evaluated molecular genetic variability within 135 traditional and new world hop cultivars. Two sets of 10 markers effectively differentiated all used cultivars, with the exception of cultivars derived from the same original genotype such as Saaz, Spalt, Tettnang and Nadwislawsky. Results of molecular genetic variability analyses corresponded with the genealogical and geographical origin of the key cultivars.

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Traditional hop (Humulus lupulus L.) cultivars have been used in the brewing industry for a long time. Globally, about ten new breeding lines were released to the market in each decade from ~1970 to 1999. Since 2006, the rate of release of new cultivars has increased tenfold. It is, therefore, important to identify their genotype and origin. Molecular genetic methods based on DNA are the most appropriate technology for this purpose. Recently, we developed an efficient marker system for the authenticity control of hop genotypes based on expressed sequence tag-simple sequence repeats (EST-SSR). In the present study, we enlarged the previously established EST-SSR set with 27 new polymorphic markers and evaluated molecular genetic variability within 135 traditional and new world hop cultivars. Two sets of 10 markers effectively differentiated all used cultivars, with the exception of cultivars derived from the same original genotype such as Saaz, Spalt, Tettnang and Nadwislawsky. Results of molecular genetic variability analyses corresponded with the genealogical and geographical origin of the key cultivars. [ABSTRACT FROM AUTHOR]

The Opuntia spp., most likely few individuals, were introduced in the Iberian Peninsula in the beginning of the 16th century, after the discovery of America, spreading afterwards throughout the Mediterranean basin. We analysed, for the first time, the genetic diversity in a set of 19 Portuguese Opuntia spp. populations from the species O. ficus-indica, O. elata, O. dillenii and O. robusta using nuclear microsatellite (nuSSR) markers. The Italian cultivars 'Bianca', 'Gialla' and 'Rossa' were included in the study for comparison purposes. The nuSSR amplifications produced from five to 16 alleles, with an average of 9.2 alleles per primer pair, and average polymorphism information content of 0.71. The estimated Dice coefficient among populations varied from 0.26 to 1.0, indicating high interspecific genetic diversity but low genetic diversity at the intraspecific level. The hierarchical clustering analysis revealed four major groups that clearly separated the four Opuntia species. Among the O. ficus-indica populations, two sub-clusters were found, one including the white pulp fruits (with cv. Bianca) and the other with the orange pulp ones and including the cv. Gialla, the cv. Rossa, and one pale yellow pulp population. No genetic differences were found between the inermis form, O. ficus-indica f. ficus-indica, and the rewilded spiny one, O. ficus-indica f. amyclaea. The dendrogram indicated that the clustering pattern was unrelated to geographical origin. The results revealed a low level of genetic diversity among the Portuguese populations of O. ficus-indica. [ABSTRACT FROM AUTHOR]

Sunflower is one of the most important oilseed crops. Evaluation of genetic diversity and grouping of genotypes and lines are computed as important agents for plant breeding programms. In this study, the genetic diversity and classification of some advanced inbred lines of sunflower developed during different breeding programs were studied using ISSR markers. Among 21 primers, 15 ISSR primers were selected for their reproducibility. A total of 70 bands were produced through ISSR primers which 27 and 43 bands out of them were monomorphic and polymorphic, respectively. Results revealed that primer UBC 807 (0.4) had the highest polymorphism information content value and primer UBC 804 (0.15) had the lowest value. Using Dice similarity coefficient the lowest amount of genetic similarity (0.65) was observed between breeding lines SF25 with SF278 and the highest ones (0.93) was observed between lines HA336 and SF315. Cluster analysis using UPGMA algorithm was divided the studied lines into 8 separate groups. Regarding to principal coordinates analysis; each component accounts a small percentage of the total variation which emphasis on good genomic distribution of selected ISSR primers.

Analysis of genetic diversity is a major step for understanding evolution and breeding applications. Recent advances in the application of the polymerase chain reaction make it possible to score individuals at a large number of loci. The RAPD technique has been successfully used in a variety of taxonomic and genetic diversity studies. The genetic diversity of 18 accessions of Thymus kotschyanus collected from different districts of Iran has been reported in this study, using 30 random amplified polymorphic DNA primers. Multivariate statistical analyses including principal coordinate analysis (PCOA) and cluster analysis were used to group the accessions. From 29 primers, 385 bands were scored corresponding to an average of 13.27 bands per primer with 298 bands showing polymorphism (77.40%). A dendrogram constructed based on the UPGMA clustering method revealed three major clusters. The obtained results from grouping 18 accessions of T. kotschyanus with two studied methods indicated that in the most cases the applied methods produced similar grouping results. This study revealed nearly rich genetic diversity among T. kotschyanus accessions from different regions of Iran. The results showed RAPD marker was a useful marker for genetic diversity studies of T. kotschyanus and it was indicative of geographica variations.

ISSR molecular marker was used to investigate genetic diversity of 'Dare Gazi' genotypes of Mashhad Esteghlal orchard and its relationship with other commercial and native cultivars of pear. Among 'Dare Gazi' genotypes of Mashhad Esteghlal orchard 23 genotypes were selected base on difference in tree vigor, leaf color, shape and color of fruit and also 33 other commercial and native pear cultivars from Esteghlal orchard and other Mashhad commercial orchards were studied. A total number of 230 DNA fragments were obtained using 11 primers of which 225 were polymorphic. On average, each primer produced 20.9 bands. Dice similarity coefficient ranged from 0.27 (between 'Dom Kaj' and Asian pear) to 1 (between 'Dare Gazi' 1 and 2 genotypes). Sample cluster dendrogram indicated that 56 genotypes were divided into 12 distinct clusters. The dendogram generated on the principle of Unweight Pair Wise Method using Arithmetic Average (UPGMA) was constructed by Dice coefficient and the genotypes were grouped into 12 clusters. 'Dare Gazi' genotypes did not show 100% similarity due to seed propagation or mutation, as 'Dare Gazi' 3 and 18 genotypes had the lowest similarity coefficient (0.64). Asian pears were placed in a separate group from European pears. And 'Dare Gazi' genotypes from different orchards were grouped separately, but all of them are called as 'Dare Gazi' pear for convenience. ISSR molecular marker can well identify the genetic variability among genotypes and cultivars and found suitable for grouping them. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sugarcane is an important crop that caters about 80 percent sugar requirement of the world. Modern day cultivated sugarcane is a complex hybrid between its few species like Saccharum officinarum L. and S. spontaneum L. having complex aneuploidy genomes with almost eight sets of basic chromosome number. Its flowering behaviours in the country and use of setts as seed narrow downs its genetic base. Molecular characterization provides the basis for determining its variability to start reasonable breeding program. Microsatellite markers have the unique ability to determine the extent of genetic divergence among sugarcane genotypes. In present study 49 SSR primers were utilized for selection of genetically diverse genotypes among 20 sugarcane cultivars adopted in Pakistan. A total of 420 bands were generated with a size range from 50 bp to 600 bp. The total number of bands generated by single primers pair ranged from 3 to 22. Polymorphic information contents (PIC) estimated ranged from 0.7 to 0.3. Cluster analysis grouped genotypes into four distinctive clusters at 70% genetic homology. Principal Coordinate analysis generated 50.04% variation from first 4 PCoA, of which PCoA-1 and PCoA-2 accounted 31% variability. PCoA divided genotypes into 4 groups in a similar pattern as generated with cluster analysis and authenticated the results of cluster analysis. Four genotypes viz; and were selected for future breeding endeavours S-03-US-694, S-05-FSD-307, S-08-FSD-19 HSF-240 involving crossing between genotypes that may provide valuable strategies for pyramiding beneficial gene(s) in novel sugarcane cultivars. It is concluded that use of SSR marker is very reliable approach for identification of diverse genotype(s) where phenotypic similarity of the cultivars leads to difficulty while selections of parents for hybridization. [ABSTRACT FROM AUTHOR]

The present study examines the leaf variations in leaf traits of four Hoya R. Br. species from Philippines namely: (1) H. buotii Kloppenburg, (2) H. halconensis Kloppenburg, (3) H. mindorensis Schlechter red bearing flowers; and (4) H. mindorensis Schlechter yellow bearing flowers. Leaf samples (n= 30 leaves) were collected from each plant group and measured with nine architectural traits. The results showed variability in the leaves using univariate and multivariate analysis. Data ordination depicted variations in leaf morphology. The two plant groups H. mindorensis red bearing flowers and H. mindorensis yellow bearing flowers were consistently variable as supported by principal coordinate analysis, cluster analysis and two way Anova (P<0.001). The variability of the two plant groups could be due to developmental instability, plasticity or taxonomic identity, one being the subspecies of the other. Hence, a closer study to investigate the significant variability of the two plant groups was recommended. Distinct separation of H. buotii and H. halconensis was detected being regularly mistaken as one species. The study demonstrated the applicability of multivariate analysis as effective tool in numerical taxonomy. Multivariate analysis can be employed to demonstrate likelihood of relationship among various Hoya species. [ABSTRACT FROM AUTHOR]

Aromatic rice is a kind of specialty rice of the world and is nature's gift to Indo-Pak region. The study aims to evaluate the genetic diversity and relationship among 40 aromatic rice comprising 34 small and medium-grained aromatic rice along with 6 long-grained Basmati rice through microsatellite marker (SSR) analysis using 24 primerpairs, of which 22 (91.6%) were polymorphic. In total, 51 alleles were detected for 22 polymorphic primer-pairs, with an average of 2.3 alleles per locus. Polymorphism Information Content (PIC) values ranged from 0.05 to 0.57 with an average of 0.33. Four SSR loci revealed PIC values higher than 0.50 and are RM224, RM257, RM241 and RM217. The genotype 'Ganjeikalli' discriminated from rest of genotypes and the basmati-types distinguished from non-basmati types by SSR markers, 'RM249' and 'RM104', respectively. Dendrogram based on the cluster analysis by microsatellite polymorphism, grouped 40 aromatic rice genotypes into 2 major clusters at simple matching (SM) coefficient value of 0.48. Both cluster I and II were divided into 2 subclusters at SM coefficient value of 0.66 and 0.76 respectively, and are further formed sub-subclusters at below subcluster level on basis of eco-geographic regions of Odisha. Clustering pattern obtained in the study revealed that individuals present in cluster-I was more diverse than cluster-II. In subcluster II (i), genotype-pairs Jhingisiali and DP-24, 3114-1 and IC-257505, IC-283204 and IC-283311 were showed extreme similarity (100%) between them. Principal Coordinate Analysis (PCoA) explained that the amount of genetic variation present in SSR molecular data was 63.4% through its cumulative value of first 3 coordinates. Based on this study, the use of SSR marker as a tool to evaluate genetic diversity and their relatedness, which is essential for varietal identification, classification, purity maintenance and conservation of indigenous scented rice germplasm, was elucidated. [ABSTRACT FROM AUTHOR]

Analysis of genetic diversity is a major step for understanding evolution and breeding applications. Recent advances in the application of the polymerase chain reaction make it possible to score individuals at a large number of loci. The RAPD technique has been successfully used in a variety of taxonomic and genetic diversity studies. The genetic diversity of 18 accessions of Thymus kotschyanus collected from different districts of Iran has been reported in this study, using 30 random amplified polymorphic DNA primers. Multivariate statistical analyses including principal coordinate analysis (PCOA) and cluster analysis were used to group the accessions. From 29 primers, 385 bands were scored corresponding to an average of 13.27 bands per primer with 298 bands showing polymorphism (77.40%). A dendrogram constructed based on the UPGMA clustering method revealed three major clusters. The obtained results from grouping 18 accessions of T. kotschyanus with two studied methods indicated that in the most cases the applied methods produced similar grouping results. This study revealed nearly rich genetic diversity among T. kotschyanus accessions from different regions of Iran. The results showed RAPD marker was a useful marker for genetic diversity studies of T. kotschyanus and it was indicative of geographica variations. [ABSTRACT FROM AUTHOR]

Barley is an economically important cereal crop especially for feed and malt production, but its value as food is increasing due to various health benefits. Wild barley is the progenitor of modern day barley cultivars possessing a rich source of genetic variation for various biotic and abiotic stresses. Species-specific molecular markers have great potential for efficient introgression of these important traits from wild to cultivated barley. In the present study, 140 microsatellite markers were screened to assess the genetic variation and species-specific markers between wild and cultivated germplasm. Of these 140, a polymorphic set of 48 genomic (g SSR) and 16 EST- SSRs amplified a total of 685 alleles. Cluster analysis discriminated all 47 accessions and classified wild and cultivated genotypes into two distinct groups, according to their geographic origin. Our analysis indicated that g SSRs were more informative than EST-based SSRs. Results from PCo A analysis for species-specific alleles clearly suggest that wild barley genotypes contain a higher number of unique alleles. [ABSTRACT FROM AUTHOR]

Abstract: Sequence Tagged Microsatellite Sites (STMSs) and morphological trait markers were used to evaluate 33 rhododendron germplasm for genetic diversity assessment and discrimination power. The average genetic diversity estimates were 0.724 (morphological traits) and 0.174 (STMSs) marker datasets. The Shannon index was higher for morphological traits (1.797) than STMS (0.302). The correlation coefficients obtained by the Mantel matrix correspondence test, which was used to compare the cophenetic matrices for the two markers, showed that estimated values of relationships given for morphological and STMS were not significantly related (p >0.05). The dataset from STMS, supported by the total probability of identity (1.13×10−9) and total paternity exclusion probability (0.9999), allowed all accessions to be uniquely identified. In summary, STMS marker proved to be an efficient tool in assessing the genetic variability among old broad leaf rhododendron genotypes. The pattern of variation appeared to be consistent, and it can be used for germplasm conservation and management for restoration of historical genetic resources. [Copyright &y& Elsevier]

The objective of the present study was to characterize the diversity of 15 Festuca rubra accessions collected from northern Spain on the basis of amplified fragment length polymorphism (AFLP) and flow cytometry variation. Additionally, all accessions along with the cultivar Wilma (Festuca nigrescens ssp. nigrescens) were evaluated for susceptibility to one isolate of dollar spot fungus (Sclerotinia homoeocarpa F.T. Bennett) collected in Asturias. Five AFLP primer combinations of EcoRI and MseI produced 980 bands; 82.3% were polymorphic and used for analysis. The best combination of primers was EcoRI-AGC+MseI-CAG, because these displayed the highest degree of polymorphism. Jaccard's similarity coefficients between accessions varied from 0.30 to 0.63 and revealed low genetic similarity. Both the unweighted pair group method with arithmetic mean dendrogram and principal coordinate analysis distinguished two groups of accessions. Genetic variability in these accessions was not related to the geographic origin or to the agronomic data. Three accessions exhibited moderate resistance to dollar spot disease and may be valuable parent material for introducing this resistance in other susceptible cultivars. [ABSTRACT FROM AUTHOR]

Isozyme analysis is a valuable tool for determining genetic relationships among breeding lines and populations. The recently developed DNA technologies which can assay a greater proportion of the plant genome are providing a plentiful array of additional genomic markers. The objective of this research was to compare random amplified polymorphic DNA (RAPD) versus isozyme-based estimation of relationships among 24 accessions of a hexaploid wild oat, Avena sterilis L. The accessions were evaluated for variation in 23 enzyme systems and by 21 10-mer primers. A total of 77 polymorphic isozyme bands and 115 polymorphic RAPD bands were observed. Two matrices of genetic distances were estimated based on band presence/ absence. These matrices were subsequently utilized in cluster analysis and principal coordinate analysis. Both isozymes and RAPDs were proficient at distinguishing between the 24 accessions. The correspondence between the elements of both distance matrices was moderate ( r=0.36**). Nevertheless, the overall representation of relationships among accessions by cluster analysis and ordination was in considerable agreement. The two techniques contrasted most notably in pair-by-pair comparisons of relationships. RAPD analysis resulted in a more definitive separation of clusters of accessions. The most significant impact of the DNA-based markers probably will be the more accurate determination of relationships between accessions that are too close to be accurately differentiated by isozymes. [ABSTRACT FROM AUTHOR]