Genetics of anthracnose panel canker disease resistance and its relationship with yield and growth characters in half-sib progenies of rubber tree (Hevea brasiliensis)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The amphibian tree of life

The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit HI (12S and 16S ribosomal RNA and tRNA(Valine) genes, 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, rhodopsin, tyrosinase, and seven in absentia, and the large ribosomal subunit 28S (approximate to 2,300 bp of nuclear sequences; ca. 1.8 million base pairs; x ($) over bar = 3.7 kb/terminal). The dataset includes 532 terminals sampled from 522 species representative of the global diversity of amphibians as well as seven of the closest living relatives of amphibians for outgroup comparisons.

Floristic composition of the tree stratum of a semideciduous mesophytic forest in the municipality of Jahu, SP, Brazil

A floristic study was carried out in an area of semideciduous mesophytic forest, lied in the municipality of Jahu, São Paulo State, Brazil. Due to the fact of the forest be crossed by three small rivers, for the sampling process, the forest was divided in two sampling areas: Area I (under the influence of the rivers) and Area II (without this influence). Differences in the abundance of some species between the two sampling areas were observed.

The absolute configuration of 1-(3 ',4 '-dihydroxycinnamoyl)cyclopentane-2,3-diol from the Amazonian tree Chimarrhis turbinata

An antioxidant, 1-(3',4'-dihydroxycinnamoyl) cyclopentane-2,3-diol [ or ( E)-2,3-dihydroxycyclopentyl-3-(3',4'-dihydroxyphenyl) acrylate ( 1)], and two known trans- and cis-chlorogenic acid methyl esters were isolated from the ethanolic extract of the leaves of Chimarrhis turbinata. The relative configuration of 1 was determined by NMR and by comparison of the circular dichroic spectrum ( CD) with those of the enantiomers of synthetic 3', 4'-dimethoxycinnamoyl analogues. The absolute configuration of one of the synthetic enantiomers was determined using the CD exciton chirality method. This established the structure of naturally occurring 1 as (E)- 2,3-dihydroxycyclopentyl- 3-(3', 4'-dihydroxyphenyl) acrylate.

Evaporative water loss and oxygen uptake in two casque-headed tree frogs, Aparasphenodon brunoi and Corythomantis greeningi (Anura, Hylidae)

Evaporative water loss (EWL) and oxygen uptake ((V) over dot o(2)) was measured in two species of tree frogs with cranial co-ossification, Aparasphenodon brunoi and Corythomantis greeningi. Both species use their head to seal the entrance of bromeliads, tree holes or rocky crevices used as shelters. EWL was significantly reduced in sheltered individuals of both species as compared with those exposed nude to desiccation. EWL per unit area through the head surface was significantly lower than the body skin for A. brunoi but not for C., greeningi. EWL per unit surface area through C. greeningi body skin was about 50% that of A. brunoi, indicating a less permeable skin in the former species. The relationship between cranial coossification and EWL is discussed. ((V) over dot o(2)) in A. brunoi was comparable with other anurans of similar size, whereas in C. greeningi, it was lower than predicted from body mass. Moreover, ((V) over dot o(2)), in C. greeningi showed less sensitivity to temperature increase than in A. brunoi. C. greeningi occurs in a drier environment than A. brunoi, and this appears to be reflected in their EWL and ((V) over dot o(2)) characteristics. (C) 1997 Elsevier B.V.

Mineralogy and forms of potassium in red yellow latosol of a guava (Psidium guajava) tree orchard

A trial was conducted during 1994-95 to study the effect of potassium fertilization on a guava (Psidium guajava L.) culture for 3 years. The control plots (without K) showed fruit production and potassium exportation that did not agree with the levels obtained by chemical analysis of the soil. Physical, chemical, mineralogic and morphologic analyses were performed on the red yellow latosol to identify minerals able to supply potassium, with emphasis on the fact that guava trees have a considerably widespread root system. The results obtained confirmed the presence of minerals in this soil that can supply potassium to the trees through weathering. Feldspars were identified in the silt fraction and micas in the clay fraction by X-ray diffractometry. The determination of total potassium revealed that the silt fraction of the soil had the largest absolute amounts of potassium, followed by clay. However, in view of its greater content, clay was the fraction that contributed most to the total amounts of potassium detected.

Phytosociological study on the tree stratum of a semideciduous mesophytic forest in the municipality of Jau, SP, Brazil

Through the point-centered quarter method, a phytosociological study was carried out in an area of semideciduous mesophytic forest with 190 ha, in the municipality of Jahu,SP. Due to the fact of the forest be crossed by three small rivers, for the sampling process, the Total Area was divided in two sampling areas: the Area I (under the influence of the rivers) and the Area II (without this influence). Some differences between the two regions were observed.

EXTRAFLORAL NECTARIES IN THE TROPICAL TREE GUAREA-MACROPHYLLA (MELIACEAE)

This paper describes the anatomy and morphology of the complex nectary systems of the tropical tree Guarea macrophylla Vahl (Meliaceae) and presents the first record of extrafloral nectaries occurring on reproductive organs (fruits) of a member of the order Sapindales. The extrafloral nectaries of G. macrophylla occur on petioles, petiolules, the abaxial surface of all leaflets, leaf buds, and over the surface of fruits. All extrafloral nectaries are distinctly raised above the surface. Foraging ants collect extrafloral nectar on Guarea trees both day and night. We suggest that the presence of extrafloral nectaries might be a useful taxonomic character for the identification of Guarea species.

Preliminary study of a methodology based on the degree-days concept for predicting the phenological phases of crops

This work develops a methodology (using the degree-days concept and linear regression), to forecast the duration of phenological phases in crops. An experiment was conducted in the greenhouse with three cultivars of cowpea (Vigna unguiculata (C.) Walp.), cv. California-781, Tvx 5058-09C and IT 81D-1032. The methodology was based on the relative thermal efficiency rate, determined for each species or cv. The results show that the proposed methodology may be a good alternative in works involving crops, especially because it does not require the repetition of the experiments.

Floristic composition of the tree stratum of a semideciduous mesophytic forest in the municipality of Botucatu, São Paulo state

The floristic composition was studied in an area of semideciduous mesophytic forest, with 120 ha, in the municipality of Botucatu, SP, Brazil. This forest lies on the ascent of the Cuesta of Botucatu. Due to the heterogeneity of the relief, for the sampling process, the forest was divided in three regions: the upper one (comprising the strip of forest on the plateau), middle on (the forestal area lied on the ascent properly said) and the lower one (the strip of forest on the plain). The tree sampling regions showed some differences among them and this must be connected to the differences in the soil.

A REACHABILITY TREE FOR STATECHARTS AND ANALYSIS OF SOME PROPERTIES

Statecharts are an extension to finite state machines with capability for expressing hierarchical decomposition and parallelism. They also have a mechanism called history, to remember the last visit to a superstate. An algorithm to create a reachability tree for statecharts is presented. Also shown is how to use this tree to analyse dynamic properties of statecharts; reachability from any state configuration, usage of transitions, reinitiability, deadlocks, and valid sequence of events. Owing to its powerful notation, building a reachability tree for statecharts presents some difficulties, and we show how these problems were solved in the tree we propose.

Diversity and geographical distribution of phytoplasmas infecting China-tree in Argentina

Yellows diseases associated with phytoplasmas cause high mortality in China-tree (Melia azedarach) in Argentina, but there has been no previous large-scale survey to determine their diversity and geographical distribution. To assess the presence and identity of phytoplasmas affecting this species throughout the country, 425 samples of symptomatic trees collected at different geographic locations were analysed by a polymerase chain reaction (using universal and group-specific primers) and restriction fragment length polymorphism. Phytoplasmas belonging to 16SrIII-B group were detected at almost every location sampled, whereas 16SrXIII-C group phytoplasmas, reported for the first time in Argentina, were only found in two regions sharing similar agro-ecological characteristics (Northeast provinces and Tucuman). Double infections with 16SrIII-B and 16SrXIII-C group phytoplasmas were also recorded. Nucleotide sequencing of the 16S rDNA of three Argentinian 16SrXIII-C group phytoplasma isolates revealed high identity (99.6-99.3%) with the CbY1 isolate reported from Bolivia.

Amazonian tree mortality during the 1997 El Nino drought

In 1997, the Amazon Basin experienced an exceptionally severe El Nino drought. We assessed effects of this rare event on mortality rates of trees in intact rainforest based on data from permanent plots. Long-term (5- to 13-year) mortality rates averaged only 1.12% per year prior to the drought. During the drought year, annual mortality jumped to 1.91% but abruptly fell back to 1.23% in the year following El Nino. Trees dying during the drought dirt not differ significantly in site or species composition from those that died previously, and there was no detectable effect of soil texture on mortality rates. These results suggest that intact Amazonian rainforests are relatively resistant to severe El Nino events.