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Presents information on a study which reconstructed the phylogeny of the tropical tree family, Dipterocarpaceae based on nucleotide sequence. Characteristics of the family; Data collection and analysis; Results and discussion.

AbstractDeforestation and selective logging in the tropics may have serious consequences on genetic processes in tropical tree populations, affecting long-term survival of a given species as well as tropical forest communities. Because understanding the effects of human-induced changes on genetic processes is of utmost importance in formulating sound conservation and management plans for tropical forest communities, we developed microsatellite or simple sequence repeat (SSR) markers for the tropical tree Carapa guianensis (Meliaceae) and assessed the polymorphism of SSRs in adult and sapling populations in a large contiguous forest and in selectively logged and fragmented forests. The number of alleles in polymorphic loci ranged between 4 and 28. No inbreeding was detected in saplings or adult cohorts, but the allelic richness was lower in the sapling cohort of the isolated fragment. Genetic distances, Nei’s D and (δµ)2, and RST values among saplings were greater than among adult cohorts, suggesting restriction of gene flow due to deforestation and habitat fragmentation. These SSR loci may be used to address many related questions regarding the population and conservation genetics of tropical trees. [ABSTRACT FROM AUTHOR]

Focuses on the use of microsatellites or simple sequence repeats (SSRs), in the studies of tropical trees (Leguminosae). Information on materials and methods used; Indepth look at the results of the parsimony analysis; Details on the discussion of the use of the microsatellites.

The article focuses on a study to find identification of novel microsatellite markers for Saraca asoca, tree species in India. Topics discussed include economic impact of Saraca asoca, information on population genetic, extraction of Genomic DNA using Polymerase chain reaction, and analysis of population genetic structure and gene flow.

Bacillus velezensis EB14, isolated from a leaf of Populus × jackii, possesses antagonistic activity against Sphaerulina musiva, a fungal pathogen of Populus sp. that causes leaf spots and stem cankers on poplars, limiting the utility of hybrid poplars as plantation trees. We sequenced the genome of B. velezensis EB14 to gain insights into the underlying basis of its antagonistic activity. Here, we report the complete genome sequence of B. velezensis EB14, a gram-positive bacterium of the family Bacillaceae. Through antiSMASH analysis, we predicted several gene clusters coding for the biosynthesis of antimicrobial compounds and several genes involved in plant bacterial interactions. These findings support the potential of developing B. velezensis EB14 as a biocontrol agent against S. musiva in poplar plantations. The genome of B. velezensis EB14 along with genome sequences of closely related B. velezensis species are invaluable for comparative genomic analyses to gain insights into bacterial, fungal, and host plant interactions. [ABSTRACT FROM AUTHOR]

Nothapodytes nimmoniana Graham (Icacinaceae) is a small tree distributed along a 1600 km mountain range in the Western Ghats biodiversity hotspot in southern India. The stem wood of N. nimmoniana accumulates high concentration (about 0.3% by dry weight) of the anti-cancer alkaloid, camptothecine (CPT). Several endophytic fungi isolated from this plant have been shown to produce camptothecine in vitro. In this study, we examined the diversity and distribution of fungal endophytes of N. nimmoniana along its entire distributional range in the Western Ghats and investigated if the CPT-producing endophytes are restricted to any specific clade. The leaf and stem of N. nimmoniana were sampled from 18 sites along the Western Ghats spanning 8-18°N lat. Endophytes were recovered from all sites with the colonization frequency ranging from 0% to 52% across the sites. One hundred and four endophytic fungal isolates were recovered from 118 plants and characterized both morphologically and by sequencing the internally transcribed spacer region of the nuclear rDNA gene. The fungal isolates belonged to 45 species (44 Ascomycetes and one Basidiomycetes). Fusarium and Hypoxylon were the most predominant genera comprising over half of the total isolates. Interestingly, CPT-producing endophytes were not restricted to any specific clade. We discuss these results in the context of the growing interest in endophytic fungi as possible alternative sources of plant secondary metabolites. [ABSTRACT FROM AUTHOR]

Ninety-one young-of-the-year Atlantic salmon Salmo salar were captured using a non-invasive snorkelling technique in a 38 m section of Catamaran Brook, New Brunswick, Canada, to test whether related fish settle closer to one another than unrelated fish. A maximum likelihood estimate of parentage relationships assessed by genotyping eight microsatellite loci revealed five half-sibling families in the sample of fish. Related juvenile S. salar were not found closer to one another than unrelated fish in three analyses at two spatial scales: a comparison of the relatedness of focal fish to their nearest neighbour and to their four nearest neighbours, and a correlation of the pair-wise relatedness and distance matrices for all fish in the sample. The lack of a kin-biased dispersion pattern may be related to the lower density of fish or the scarcity of full-siblings at the study site compared to laboratory conditions. [ABSTRACT FROM AUTHOR]

Proposes a paradigm shift in the explanation of the observed patterns of seed abortion in Dalbergia sissoo by extending the principles of sociobiology to plants. Estimation of genetic relatedness between seed pairs; Number of seeds and ovules and seed to ovule ratios of five trees of Dalbergia sissoo examined; Distribution of the similarity index among single-seeded pods and pairs of seeds within each of the two-seeded pods.

Abstract:We compared deforestation rates and the extent of fragmentation inside and outside protected areas in the Sarapiquí region of Costa Rica. We determined deforestation rates using remotely sensed images with supervised classification. We georeferenced the processed images and then transformed them to vector format for final mapping and parameter quantification. The deforestation rate in protected areas was low and declined sharply from 0.56% annually between 1976 and 1986 to 0.16% from 1991 to 1995. Outside the protected areas, the rate decreased from 3.6% in 1976–1986 to 2.8% in 1986–1991, but it increased again to 3.2% in 1991–1995. Fragmentation outside the protected areas increased considerably: the number of patches increased from 537 in 1976 to 1231 in 1996, while during the same period the average size of patches decreased from 0.95 to 0.25 km2. Forest landscapes in the Sarapiquí region are likely to lose considerable biodiversity because of the past forest loss and fragmentation even without further increases in deforestation and fragmentation. [ABSTRACT FROM AUTHOR]

Nothapodytes nimmoniana is a medicinally important tree species that occur in the Western Ghats, a megadiversity hotspot in southern India. Inner stem bark of the tree contains an important anti-cancer alkaloid, camptothecin for which the natural population of the tree is heavily harvested. In this paper, we report the isolation and characterization of eight polymorphic microsatellite loci using enrichment hybridization protocol. Analysis of 36 individuals representing two populations revealed three to 12 alleles per locus. Observed heterozygosity ranged from 0.21 to 0.94 for the two populations. None of the loci tested showed linkage disequilibrium. These markers are invaluable for evaluating the genetic structure and assessing the genetic impacts of harvesting of N. nimmoniana in the Western Ghats to formulate strategies for conservation of the species. [ABSTRACT FROM AUTHOR]