http://www.mdpi.com/journal/diversity/special_issues/plant-genetic-div/ Dear Colleagues, Convention on the Biological Diversity and the Pan-European Biological and Landscape Diversity Strategy define biodiversity as the variety of life and its processes. Biodiversity is generally recognized on three levels: · Genetic diversity - the variety of genetic building blocks found among individual representatives of a species; · Species diversity – the variety of living organisms found in a particular place; · Ecosystem diversity - the variety of species and ecological functions and processes, both their kind and number, that occur in different physical settings. In this Diversity’s special issue we focus on the first level “genetic diversity” restricting it to the Plant aspects since the conservation and sustainable use of plant genetic resources are essential to the sustainable development of agricultural production. Plant genetic resources comprise the diversity of genetic material contained in traditional varieties and modern cultivars, as well as crop wild relatives and other wild plant species that can be used, now or in the future, for food and agriculture, including resources which contribute to people’s livelihoods by providing food, medicine, feed for domestic animals, fibre, clothing, shelter, energy and a multiple of other products and services. In this special issue will be published contributions assessing the genetic diversity in Plant species as well as contributions focusing on the aspect connected with this such as statistical methods and tools used. Mario A. Pagnotta Guest Editor Related Journal Genes - an Open Access journal of genetics and genomics. Submission Information All manuscripts should be submitted to diversity@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website. Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Diversity is an international peer-reviewed Open Access monthly journal published by MDPI. For the first two issues, to be published in 2009 and 2010, the Article Processing Charges (APC) will be waived for well-prepared manuscripts. English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections. http://www.mdpi.com/1424-2818/2/6/837/ The long tradition of common bean cultivation in Italy has allowed the evolution of many landraces adapted to restricted areas. Nowadays, in response to market demands, old landraces are gradually being replaced by improved cultivars. However, landraces still survive in marginal areas of several Italian regions. Most of them appear severely endangered with risk of extinction due to the advanced age of the farmers and the socio-cultural context where they are cultivated. The present contribution is an overview of the state of the art about the knowledge of Italian common bean germplasm, describing the most important and recent progresses made in its characterization, including genetic diversity and nutritional aspects. http://www.mdpi.com/1424-2818/2/6/837/ Thu, 27 May 2010 00:00:00 CEST Diversity 2010-05-27 2 6 Review 837 862 1424-2818 Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality 2010-05-27 doi: 10.3390/d2060837 Piergiovanni Lioi http://www.mdpi.com/1424-2818/2/5/768/ Genetic resources of crop plants are essential for crop breeding. They are conserved in gene banks in form of a large numbers of accessions. These accessions harbor allelic variants of agronomically important genes and molecular tools allow a rapid assessment of this allelic diversity. Here, we have screened a collection of 1005 wheat gene bank accessions for powdery mildew resistance and a molecular characterization for functional alleles at the wheat powdery mildew resistance locus Pm3 was carried out mostly on the resistant accessions. The two analyzed sets of accessions consisted of 733 accessions originating from 20 different countries and 272 landraces originating specifically from Afghanistan. The Pm3 haplotype (indicating the presence of a Pm3-type of gene, susceptible or resistant) was found to be abundantly present in both sets. The accessions with a Pm3 haplotype were further screened for the presence of the functional Pm3a to Pm3g alleles using allele-specific molecular markers. Pm3b and Pm3c were the most frequently found alleles while the other five alleles were detected only in few accessions (Pm3d, Pm3e, Pm3f) or not detected at all (Pm3a, Pm3g). The data further showed that Pm3b is the major source of Pm3-mediated powdery mildew resistance in wheat accessions from Afghanistan. Susceptible allelic variants of Pm3 were found to be widespread in the wheat gene pool. The presented molecular analysis of Pm3 alleles in a diverse set of wheat accessions indicates that several alleles have defined geographical origins. Possibly, the widespread Pm3b and Pm3c alleles evolved relatively early in wheat cultivation, allowing their subsequent diffusion into a broad set of wheat lines. http://www.mdpi.com/1424-2818/2/5/768/ Wed, 19 May 2010 00:00:00 CEST Diversity 2010-05-19 2 5 Article 768 786 1424-2818 Genetic Diversity of the Pm3 Powdery Mildew Resistance Alleles in Wheat Gene Bank Accessions as Assessed by Molecular Markers 2010-05-19 doi: 10.3390/d2050768 Bhullar Mackay Keller http://www.mdpi.com/1424-2818/2/4/439/ Tobacco (Nicotiana tabacum L.) is an important agricultural crop plant for the economy of many countries. Assessment of the genetic diversity of cultivated tobacco varieties is of importance for long-term tobacco improvement. Microsatellite markers are currently the marker system of choice for genetic analysis of allopolyploid plants. In this study, we evaluated the use of 30 microsatellite markers for identification of 10 varieties of cultivated tobacco in the Republic of Macedonia. We found 24 of the microsatellite markers to be polymorphic and sufficient for identification of these varieties. Cluster analysis showed that Macedonian tobacco varieties are classifiable into three distinct groups. http://www.mdpi.com/1424-2818/2/4/439/ Wed, 24 Mar 2010 00:00:00 CET Diversity 2010-03-24 2 4 Article 439 449 1424-2818 Genetic Variability of Macedonian Tobacco Varieties Determined by Microsatellite Marker Analysis 2010-03-24 doi: 10.3390/d2040439 Davalieva Maleva Filiposki Spiroski Efremov http://www.mdpi.com/1424-2818/1/2/89/ Commiphora wightii is an endangered, endemic species found in the Thar Desert of Rajasthan, India and adjoining areas of Pakistan. The populations of this plant are rapidly dwindling due to overexploitation for their medicinally important resin. Analysis of nucleotide sequences of the internal transcribed spacer of rDNAs revealed low genetic diversity (π = 0.03905; θw = 0.05418) and high population structure (ϕST = 0.206). Parsimony based assessment and Bayesian analyses were conducted on the dataset. Mantel’s test showed a statistically significant positive correlation between genetic and geographic distance (r2 = 0.3647; p = 0.023). Anthropogenic overexploitation of C. wightii for its natural resources has resulted in population fragmentation. Initiatives should be taken immediately to preserve the diversity of this important plant species. http://www.mdpi.com/1424-2818/1/2/89/ Mon, 26 Oct 2009 00:00:00 CET Diversity 2009-10-26 1 2 Article 89 101 1424-2818 Intraspecific Variation in Commiphora wightii Populations Based on Internal Transcribed Spacer (ITS1-5.8S-ITS2) Sequences of rDNA 2009-10-26 doi: 10.3390/d1020089 Inamul Haque Rajib Bandopadhyay Kunal Mukhopadhyay http://www.mdpi.com/1424-2818/1/1/19/ This paper is an overview of the diverse, predominantly molecular techniques, used in assessing plant genetic diversity. In recent years, there has been a significant increase in the application of molecular genetic methods for assessing the conservation and use of plant genetic resources. Molecular techniques have been applied in the analysis of specific genes, as well as to increase understanding of gene action, generate genetic maps and assist in the development of gene transfer technologies. Molecular techniques have also had critical roles in studies of phylogeny and species evolution, and have been applied to increase our understanding of the distribution and extent of genetic variation within and between species. These techniques are well established and their advantages as well as limitations have been realized and described in this work. Recently, a new class of advanced techniques has emerged, primarily derived from a combination of earlier, more basic techniques. Advanced marker techniques tend to amalgamate advantageous features of several basic techniques, in order to increase the sensitivity and resolution to detect genetic discontinuity and distinctiveness. Some of the advanced marker techniques utilize newer classes of DNA elements, such as retrotransposons, mitochondrial and chloroplast based microsatellites, thereby revealing genetic variation through increased genome coverage. Techniques such as RAPD and AFLP are also being applied to cDNA-based templates to study patterns of gene expression and uncover the genetic basis of biological responses. The most important and recent advances made in molecular marker techniques are discussed in this review, along with their applications, advantages and limitations applied to plant sciences. http://www.mdpi.com/1424-2818/1/1/19/ Thu, 06 Aug 2009 00:00:00 CEST Diversity 2009-08-06 1 1 Review 19 35 1424-2818 Assessing Plant Genetic Diversity by Molecular Tools 2009-08-06 doi: 10.3390/d1010019 Linda Mondini Arshiya Noorani Mario A. Pagnotta