Increasing the Understanding of Plant Invasions in Southern South America: First Symposium on Alien Plant Invasions in Chile

The first symposium on Alien Plant Invasions in Chile was held in southern Chile in November of 2002. Chile represents an interesting setting to study biological invasions because of its long history of introductions, and its high rate of endemisms that makes it more prone to invasions. However, little is known about plant invasions in Chile and the country lacks a clear policy on alien species. The speakers at the symposium discussed their research on several aspects of alien plant invasions in southern Chile and Argentina. They also elaborated a list of future challenges of plant invasion ecology for the area. The package of recommendations may be useful for other developing countries with similar state of knowledge of their flora and similar environmental and economic issues. We expect that this type of meeting will help to stimulate the scientific debate about invasion ecology and the development of coordinated research to answer local questions, while contributing to find generalities in plant invasion patterns and processes.     

Bioecology of the fiddler crab <Emphasis Type="Italic">Uca uruguayensis</Emphasis> and the burrowing crab <Emphasis Type="Italic">Chasmagnathus granulatus</Emphasis> (Decapoda,Brachyura) in the Refugio de Vida Silvestre Bahía Samborombón,Argentina

The aim of the present work conducted at the Refugio de Vida Silvestre Bahía Samborombón, Argentina, is to analyse the most relevant aspects of the life cycles of Chasmagnathus granulatus and Uca uruguayensis: their abundance, size distribution and sex ratio in order to be used for make management purposes. A total of 1200 individuals of U. uruguayensis (megalopae, juveniles and adults) and 957 individuals of C. granulatus (juveniles and adults) were collected from March 2001 to February 2003. U.␣uruguayensis had a maximun density of 42 ind./m² in February 2003, while the maximun density of C.␣granulatus was 52 ind./m² in June 2001. Minimun density was zero individual for both species in July 2002. Each environmental factor sampled (temperature of water, salinity and pH) was correlated with the abundance of each species by Pearson’s linear correlation analysis. Sex ratio did not significantly differ from the expected Mendelian ratio, except for U. uruguayensis in December 2002 (male-biassed) and C.␣granulatus in June and December 2001, April 2002 and February 2003 (female-biassed). Ovigerous females of U. uruguayensis and C. granulatus were found during the summer.     

Clinical Trial of a Combination of Lynestrenol and Mestranol (Lyndiol) as an Oral Contraceptive Agent

Contraception with lynestrenol-mestranol (Lyndiol) was studied in 332 Mexican women during a period of two and one-half years. Side effects were minimal or transient. No pregnancies occurred in those who took the medication according to instructions. The women were followed with yearly pelvic examinations and Papanicolaou smears, serial endometrial biopsies and extensive studies of blood, liver and glandular function. Complete ophthalmological studies were done on 30 patients. No clinical or laboratory evidence of harmful effects could be demonstrated. Return to ovulation (using pregnanediol excretion and endometrial biopsies as parameters) occurred in all of 22 women studied in the first three post-treatment cycles. Eight posttreatment pregnancies and the resulting offspring were normal. The first post-treatment cycle, as with other oral contraceptives, was unpredictable and tended to be prolonged. It varied in length from 22 to 60 days.     

Nuclear ribosomal DNA phylogeny and its implications for evolutionary trends in Mexican Bursera (Burseraceae)

The genus Bursera (Burseraceae) is one of the most diversified and abundant groups of plants of the tropical dry forests of Mexico. In order to provide a basis for better understanding of its evolutionary biology, we reconstructed a phylogeny of 57 species and varieties using the nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) of 18S–26S and the 5.8S coding region of nuclear ribosomal DNA. We used four species of the allied genera Commiphora and Boswellia and one species of Spondias (Anacardiaceae) as outgroups. Our results support the views that Bursera is monophyletic and more closely related to Commiphora than to Boswellia. The division of Bursera into sections Bullockia and Bursera is also strongly supported by our phylogeny. Several other subclades also had high bootstrap values, especially within section Bursera. We use the phylogeny as a basis for discussing evolutionary tendencies in bark, leaves, breeding systems, and fruits.     

Development of the inner ear of the brown trout (Salmo trutta fario): II. Cytodifferentiation and innervation of sensory cells

The study of the sensory organs of the trout labyrinth by means of electron microscopy show that hair cells differentiate gradually in these organs; all of them produce new cells over a long period. The course of cytodifferentiation follows a similar pattern in all organs. Afferent nerve fibers and terminals are found at approximately the same time that sensory cells are being differentiated; the efferent synapses appear latter in development. The maturation of the both types of synapses is described. © 1993 Wiley-Liss, Inc.     

Metabolite database for root,tuber, and banana crops to facilitate modern breeding in understudied crops

Roots, tubers, and bananas (RTB) are vital staples for food security in the world's poorest nations. A major constraint to current RTB breeding programmes is limited knowledge on the available diversity due to lack of efficient germplasm characterization and structure. In recent years large‐scale efforts have begun to elucidate the genetic and phenotypic diversity of germplasm collections and populations and, yet, biochemical measurements have often been overlooked despite metabolite composition being directly associated with agronomic and consumer traits. Here we present a compound database and concentration range for metabolites detected in the major RTB crops: banana (Musa spp.), cassava (Manihot esculenta), potato (Solanum tuberosum), sweet potato (Ipomoea batatas), and yam (Dioscorea spp.), following metabolomics‐based diversity screening of global collections held within the CGIAR institutes. The dataset including 711 chemical features provides a valuable resource regarding the comparative biochemical composition of each RTB crop and highlights the potential diversity available for incorporation into crop improvement programmes. Particularly, the tropical crops cassava, sweet potato and banana displayed more complex compositional metabolite profiles with representations of up to 22 chemical classes (unknowns excluded) than that of potato, for which only metabolites from 10 chemical classes were detected. Additionally, over 20% of biochemical signatures remained unidentified for every crop analyzed. Integration of metabolomics with the on‐going genomic and phenotypic studies will enhance ’omics‐wide associations of molecular signatures with agronomic and consumer traits via easily quantifiable biochemical markers to aid gene discovery and functional characterization.     

Dealing with different methods for Kluyveromyces lactis β-galactosidase purification

Several micro-scale chromatography-based procedures for purification of the β-galactosidase from the yeast Kluyveromyces lactis were assayed. Purified enzyme was suitable to be used as antigen to induce polyclonal antibodies production. Specific staining of non-denaturing PAGE gels with chromogenic substrates allowed the determination of the number of subunits forming the native enzyme.