Yams (Dioscorea spp.) consist of approximately 600 species. Presently, these species are threatened by genetic erosion due to many factors such as pest attacks and farming practices. In parallel, complex taxonomic boundaries in this genus makes it more challenging to properly address the genetic diversity of yam and manage its germplasm. As a first step toward evaluating and preserving the gene...

We examined levels of genetic variation and genetic structure in the leafy cactus (Pereskia guamacho) in arid and semiarid zones in Venezuela. We surveyed genetic diversity within 17 populations using 19 allozyme loci. Genetic diversity was relatively high at both the species (P(s) = 89%, A(s) = 3.26, AP(s) = 3.53, H(es) = 0.24) and population (P(p) = 63%, A(p) = 1.90, AP(p) = 2.42, H(ep) = 0.2...

BACKGROUND AND AIMS The sedge genus Carex, the most diversified angiosperm genus of the northern temperate zone, is renowned for its holocentric chromosomes and karyotype variability. The genus exhibits high variation in chromosome numbers both among and within species. Despite the possibility that this chromosome evolution may play a role in the high species diversity of Carex, population-leve...

The premise that guides my research is that phytoplankton community dynamics reflect a complicated interaction between environmental variability and the inherent genetic and physiological variation present within individual species of phytoplankton. My goal is to determine how genetic and physiological diversity is maintained within individual species of diatoms and how this diversity is shaped...

Rice (Oryza sativa L.) is one of the most significant cereal crops, about 3 billion people, nearly half the world's population; depend on rice for survival and it offers up to 80% of daily energy intake in most of the Asian countries. Knowledge of the distribution, extent and pattern of genetic variation is useful for estimation of any possible loss of genetic diversity and its role in breeding...

Biodiversity at multiple levels — genotypes within species, species within functional groups, habitats within a landscape — enhances productivity, resource use, and stability of seagrass ecosystems. Several themes emerge from a review of the mostly indirect evidence and the few experiments that explicitly manipulated diversity in seagrass systems. First, because many seagrass communities are do...

Mark Vellend* and Monica A. Geber National Center for Ecological Analysis and Synthesis, 735 State Street, Suite 300, Santa Barbara, CA 93101, USA Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA *Correspondence and present address: Departments of Botany and Zoology, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada ...

different species of streptomyces are common in most types of soil. some certain species are plant pathogenic especially on potato. this study was conducted to evaluate genetic diversity among some local streptomyces spp. strains isolated from soil and infected tubers in potato farms in northwest of iran. repetitive dna elements (box, eric and rep) as genetic markers were used for diversity stu...