Cristiane Gouvêa Fajardo

Reproductive biology of Protium spruceanum (Burseraceae), a dominant dioecious tree in vegetation corridors in Southeastern Brazil

We investigated the reproductive biology of Protium spruceanum (Benth.) Engler in vegetation corridors of secondary Atlantic forest in Lavras, southern Minas Gerais State, Brazil. The reproductive phenology was investigated fortnightly over a one year period. Floral biology studies involved pollen viability analysis, nectar production, stigmatic receptivity, pollen tube growth, visiting insect species and visit rates. The small, pale yellowish flowers (0.3-0.4 cm diameter) are functionally unisexual and organized in dense inflorescences (ca. 45 flowers). P. spruceanum presented annual flowering between September and November. Staminate flowers supplied a high percentage of viable pollen (90.6%) and relatively abundant nectar (x = 4.5 μL). Pistillate flowers produced only nectar to flower visitors (x = 4.0 μL). The effective pollinators were Apis mellifera and Trigona sp. (Hymenoptera, Apidae). Pollen tubes of cross-pollinated flowers were observed entering the ovaries 48 h after pollination. The fruiting season is from October to March, with a peak in November, coinciding with the rainfall peak. Ecological implications of these findings, and alternative arguments to explain the high genetic diversity at regional landscape are discussed.

DIVERSIDADE GENÉTICA E SELEÇÃO DE INICIADORES ISSR EM UMA POPULAÇÃO NATURAL DE MANGABA (Hancornia speciosa Gomes) (APOCYNACEAE)

The knowledge of genetic diversity of native species has great value when it aims at the improvement and conservation of natural populations. In that direction, theobjective of this study is to select ISSR primers (inter simple sequence repeat) to Hancornia speciosa(Apocynaceae), as to quantify the genetic variability of a natural population. It was sampled 15 individuals of a population located in Natal/RN. Stem samples were collected for subsequent DNA extraction. For the selection, 19 IRSS primers were tested, six of them were effective, presenting clearer and numerous loci (UBC 808, UBC 810, UBC 826, UBC 827, UBC 841, UBC 842) totaling 63 loci. Of which, only 30 (47.62%) presented polymorphism. The value of PIC (polymorphic information content) for the selected primers averaged 0.37, ranging from 0.26 to 0.44. Genetic diversity was considered low in the population, with the number of observed alleles (na = 1.48), number of effective alleles (ne = 1.32), diversity index of Nei (He = 0.18) and Shannon index (I = 0.26). The allelic diversity patterns found indicates the occurrence of a recent population bottleneck. The use of ISSR markers for Hancornia speciosa is effective as measuring the genetic diversity of individuals, working as a support for strategies and plans that aim the conservation and maintenance of the species.

Distribuição Espacial de Cattleya granulosa Lindl.: Uma Orquídea Ameaçada de Extinção

Cattleya granulosa is an endemic and endangered orchid species of the coastal region of northeastern Brazil. This study aimed to evaluate the levels of spatial aggregation in a preserved population, in an area of 4.225 m2 of the conservation unit of ‘Parque das Dunas’ Natal, Rio Grande do Norte state, Brazil. We evaluated the life form of the population as well as its neighborhood density factor (NDF) to determine the spatial distribution in distance classes, using the SpPack software program. Regarding the life form, 73% of the plants (N = 136) were epiphyte and 27% were terrestrial (N = 50). The epiphytes present specificity with a single host tree, Eugenia spp. (Myrtaceae). The spatial pattern of Cattleya granulosa is aggregated, with the highest density of neighbors (NDF) within a radius of 5 m. These data suggest restricted dispersion with direct influence on actions for conservation of the species.

Distribuição Espacial de Cattleya granulosa Lindl.: Uma Orquídea Ameaçada de Extinção / Spatial Distribution of Cattleya granulosa Lindl.: An Endangered Orchid Species

Cattleya granulosa is an endemic and endangered orchid species of the coastal region of northeastern Brazil. This study aimed to evaluate the levels of spatial aggregation in a preserved population, in an area of 4.225 m2 of the conservation unit of ‘Parque das Dunas’ Natal, Rio Grande do Norte state, Brazil. We evaluated the life form of the population as well as its neighborhood density factor (NDF) to determine the spatial distribution in distance classes, using the SpPack software program. Regarding the life form, 73% of the plants (N = 136) were epiphyte and 27% were terrestrial (N = 50). The epiphytes present specificity with a single host tree, Eugenia spp. (Myrtaceae). The spatial pattern of Cattleya granulosa is aggregated, with the highest density of neighbors (NDF) within a radius of 5 m. These data suggest restricted dispersion with direct influence on actions for conservation of the species.