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Artigos
Publicados em Periódicos
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P040-00 Estrutura e dinâmica
de uma população de Collophyllum brasiliense em uma floresta
higrófila do sudeste do Brasil Marques MCM, Joly CA* Age and
spatial structures of a population of Calophyllum brasiliense
(Clusiaceae) were studied in a 3600 m2 area of a swamp forest
in Brotas, São Paulo State. During the first census, 1658
plants were tagged and after one year this number increased
to 1706. Seedling (29.7%) and juvenile (5.3%) mortality was
caused, mainly, by soil erosion and deposition during the
rainy season, because the plants were buried. Subadult (0.7%)
and adult (0%) mortality was very low. A large number of new
seedlings was concentrated in the lower parts of the study
site and in soil depressions where the water carried seeds
which were deposited and germinated. Recruitment rate for
seedlings was high (48.1%), while for juvenile (7.3%), subadult
(1.9%) and adult (0%) were much lower. Plants of all classes,
from seedlings to adults, presented a clustered distribution,
due to the topography of the study site, which facilitates
seed accumulation, and to a higher number of seeds under the
canopy of reproductive individuals. Fruit dispersion by bats
or water, seed survival under hypoxic conditions, seedling
tolerance to waterlogging, age structure with a significant
predominance of seedlings and population growth explain why
C. brasiliense is the most abundant species in the forest
studied and also in other similar forests in Southeastern
Brazil. Revista Brasileira de Botânica 23(1): 107-112, 2000.
*E-mail: cjoly@unicamp.br
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| P041-00
Estrutura da Mata da Silvicultura, uma floresta estacional semidecidual
Montana no município de Viçosa, MG Meira-Neto JAA, Martins FR*
Revista Árvore 24(2): 151-160, 2000. *E-mail: fmartins@unicamp.br |
| P042-00 Ecophysiology
and respiratory metabolism during the germination of Inga sessilis
(Vell.) Mart. (Mimosacea) seeds subjected to hypoxia and anoxia
Okamoto JM, Joly CA* This paper presents a study on the respiratory
metabolism of germinating seeds of Inga sessilis subjected to
normoxia, hypoxia and anoxia. Although it is typical of environments
where waterlogging seldom occurs, 40% of its seeds are able
to germinate under hypoxia; yet, anoxia periods over 96 h are
lethal to the seeds. Ethanol is the main product of the seeds
anaerobic metabolism, but the steep increase in lactate after
24 anoxia or 48 h hypoxia may explain the drop in seed viability.
Revista Brasileira de Botânica 23(1): 51-57, 2000. *E-mail:
cjoly@unicamp.br |
| P043-00
Nova espécie do gênero Ichthyocthere (Heliantheae-Asteraceae)
Pereira RCA, Semir J* Bradea 8(28): 155-158, 2000. *E-mail:
semir@unicamp.br |
| P044-00
A new species of Chaetostoma (Melastomataceae) from Minas Gerais,
Brazil Romero R, Martins AB* Candollea 54(2): 449-452, 2000.
*E-mail: amartins@unicamp.br
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| P045-00 Growth
and leaf demography of two Cecropia species Santos FAM* Alometria,
crescimento e demografia de folhas de uma espécie de Cecropia
associada com formigas (C. glazioui) e outra não (C. hololeuca),
foram estudadas em área de floresta Pluvial Atlântica, no SE
Brasil. As relações entre os diâmetros dos caules e as alturas
das plantas foram semelhantes nas duas espécies. Cecropia glazioui
apresentou maior crescimento anual e entrenós maiores que C.
hololeuca. A emerg6encia e a mortalidade de folhas foram sazonais
nas duas espécies, sendo o número de folhas mais variável ao
longo do ano em C. hololeuca que em C. glazioui. As curvas de
sobrevivência de folhas foram intermediárias entre os Tipo I
e Tipo II de Deevey, sendo que folhas jovens de C. glazioui
apresentam probalidade de sobrevivência e expectativas de vida
maiores que as de C. hololeuca. A produção de folhas menos variável
durante o ano, e a maior sobrevivência de folhas novas em C.
glazioui podem estar relacionadas à associação com formigas.
Revista Brasileira de Botânica 23(2): 133-141, 2000. *E-mail:
fsantos@unicamp.br |
| P046-00
The pollination of Stenorrhynchos lanceolatus (Aublet) L. C.
Rich. (Orchidaceae: Spiranthinae) by hummingbirds in southeastern
Brazil Singer RB, Sazima M* Hummingbird pollination is documented
for a natural population of Stenorrhynchos lanceolatus Aublet.
L. C. Rich. occurring in Rio de Janeiro State, southeastern
Brazil. The plants are pollinated by Phaethornis eurynome (Phaethorninae),
Thalurania glaucopis (females only) and Leuchochloris albicollis
(Trochilinae). The plants offer nectar as a reward and the pollinaria
become stuck to the surface of the hummingbirds. The orchid
population received a few (0-4) hummingbird visits per day,
with about 83% of the flowers being pollinated. In spite of
the low frequency of visits, the granular structure of the pollinarium
plus the behaviour of the most frequent pollinators, a very
high fruiting success was promoted. The pollinaria may remain
up to 6.30 hours on the hummingbird's bill, enhancing the chances
of cross-pollination and long-distance pollen flow. Plant Systematics
and Evolution :221-227, 2000. IF= *E-mail: msazima@unicamp.br
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| P047-00
Anatomia do eixo vegetativo de Dahlstedtia pinnata (Benth.)
Malme e D. pentaphylla (Taub.) Burk. (Leguminosae, Papilionoideae)
Teixeira SP*, Gabrielli AC Revista Brasileira de Botânica 23(1):
1-11, 2000. *Phone: 3788-7844 |
| P048-00 Secretory
cavities and pellucid dots in leaflets of Lonchocarpus (Leguminosae,
Papilionoideae, Millettieae) Teixeira SP, Castro MM, Tozzi AMGA*
The occurrence of leaflet secretory cavities in 23 Brazilian
species of Lonchocarpus was surveyed anatomically and compared
with data from external morphology to evaluate their taxonomic
significance. This study reveald three cases: presence of secretory
cavities associated with pellucid dots, pellucid dots corresponding
to false secretory cavities, and absence of pellucid dots and
secretory cavities. These results indicate that in this genus
the "glandular pellucid dots" cited in morphological descriptions
do not always correspond to secretory cavities, and that their
nature must always be confirmed by histological sections. Secretory
cavities have systematic significance at subgeneric taxonomic
level for the genus Lonchocarpus. Plant Systematics and Evolution
221(1-2): 61-68, 2000. IF = 1.302 *E-mail: anatozzi@unicamp.br |
| P049-00 Structural
and functional characterization of myotoxin I, a Lys49 phospholipase
A(2) homologue from Bothrops moojeni (Caissaca) snake venom
Soares AM, Andriao-Escarso SH, Angulo Y, Lomonte B, Gutierrez
JM, Marangoni S*, Toyama MH, Arni RK, Giglio JR Myotoxin-I (MjTX-I)
was purified to homogeneity from the venom of Bothrops moojeni
by ion-exchange chromatography on CM-Sepharose. Its molecular
weight was estimated by SDS-PAGE. Protein sequencing indicated
that MjTX-I is a Lys49 myotoxin and consists of 121 amino acids,
containing a high proportion of basic and hydrophobic residues.
It shares a high degree of sequence identity with other Lys49
PLA(2)-like myotoxins, but shows a significantly lower identity
with catalytically active Asp49 PLA(2)s. The three-dimensional
structure of MjTX-I was modeled based on the crystal structures
of three highly homologous Lys49 PLA(2)-like myotoxins.. Although
the myotoxic and lethal activities of the modified toxins were
reduced by these treatments, neither its edema-inducing or Liposome-disrupting
activities were significantly altered. Rabbit antibodies to
native MjTX-I cross-reacted with the chemically modified forms,
and both the native and modified MjTX-I preparations were recognized
by antibodies against the C-terminal region 115-129 of myotoxin
II from B. asper, a highly Lys49 PLA(2)-homologue with high
sequencial similarity. Archives of Biochemistry and Biophysics
373(1): 7-15 , 2000. IF = 2.386 *E-mail: marango@unicamp.br
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