Erneida Coelho de Araujo

Caracterização morfológica de frutos, sementes e plântulas de Sesbania virgata (Cav.) Pers

Sesbania Virgata is a bush, pioneer and occurs naturally Brazil. It belongs to the Leguminosae-Faboideae family and is indicated for recovery-degraded areas due to its rusticity and capacity of establishing symbiosis with rhizobial. But, in spite of its wide distribution, to date there is no morphologic description of the propagation structures and the plantule. This study describes the morphologic characters of the fruits, seeds and plantules, and characterizes the germination process of Sesbania virgata. For the study of the fruit, the following aspects were observed: type; color; dimensions; texture and consistence of the pericarp; opening; and number of seeds per fruit. The aspects observed for the seeds were: color; dimensions; weigt of 1000 seeds; tegument texture and consistency; form; embroider (?), hilum and other structures position and embryo characteristics. The plantules were characterized at two stages. The plantule stage was considered when the foliage leaves were totally formed and at young plant stage starting from the appearance of the 2nd foliage leaf. The described and cultured vegetative elements were root (main and secondary), collar, hypocotyls, cotyledons, epicotyls, foliage leaf (1st and 2nd orders) and stem. The Sesbania Virgata fruit is an indehiscent legume measuring 5,8 cm with 2 to 6 seeds. The Sesbania Virgata seeds are kidney-shaped and endospermic and there is no internal tegument. The hilum and the strophiole are easily distinguishable. The apical axis-embryo is inserted in the cotyledons. The seed germination is the epigeal type.

Crescimento de mudas de mangue sob diferentes níveis de sombreamento na península de Ajuruteua, Bragança, Pará

The purpose of this study was to evaluate the influence of different levels of shading on the development of seedlings of three mangrove species (Avicennia germinans (L.) Stearn., Rhizophora mangle L. and Laguncularia racemosa (L.) Gaertn. f.). The experiment was conducted at the community of Tamatateua, Ajuruteua peninsula, Braganca, PA, Brazil. For seedling production, the propagules and seeds of the mangrove species were planted in polyethylene bags (17 x 27 cm), filled with a typical mangrove substrate. The seedlings of the three species were grown under full sun (0), 30% and 60% shading, in a completely randomized design, a 3 x 3 factorial (three species and three shading levels), with eight seedlings per replication. After nine months under shading, plant samples were taken. The variables evaluated were: the shoot/height ratio, stem diameter, shoot dry matter, stem mass, root dry matter, total dry mass matter and morphological indices. Growth of seedlings of R. mangle occurred at all light levels. Seedlings of A. germinans grew faster at full sun and at 30% shading. Whereas, seedlings of L. racemosa were able to grow at 30 and 60% shading, but they also grew faster at full sunlight.

Estádio de maturação e qualidade de sementes após repouso de frutos de maracujá amarelo

Investigation on the effect of rest of fruits on seed quality has shown a direct relationship between rest and increase in the seed germination and vigor. The objective of this study was to evaluate the influence of the degree of maturation and fruit rest on the physiological quality of passion fruit seeds. The fruits were obtained by hand pollination, and the fruits were harvested at three maturation stages: 55, 65 and 75 days after anthesis and stored at 25 and 8 oC for 7, 14 and 21 days of rest. To evaluate the seed quality, the following characteristics were assessed: mixture content, seed dry matter, germination and vigor. Seeds from 65-day-old fruits and submitted to rest for 7 days, kept in a cooled environment and at room temperature showed better physiological quality; 65-day-old fruits harvested at anthesis and stored fo seven days at 8oC and 25oC presented also the largest accumulation of dry matter.

Effect of storage and male ancestor on the quality and micromorphology of passionfruit seeds

The storage of passion fruit seeds has been investigated by some authors, because their propagation is usually through seed. Another aspect to be evaluated was the influence on pollination by the pollen donor plant, which according to some authors can contribute to obtaining better quality fruits and seeds. The objectives of this research were to evaluate the quality of the seeds, after twelve months of storage, considering the influence of the plant pollen donor (male ancestor) on the seed quality and describe the ontogenesy of the micromorfology of the seeds from fruits at different maturation stages. The fruits were obtained by controlled hand pollination and hand pollination, and the fruits were collected at four maturation stages: 55, 58, 61 and 64 days of age after anthesis. The arilo was removed and the seeds were stored in a laboratory environment and refrigerated for 12 months and then submitted to germination and vigor tests. The control of male progenitor did not influence the seed quality; the storing the seeds for one year in a refrigerated environment promoted an increase in the germination and vigor of the seeds of Yellow Passion fruit, and the best results were obtained for seeds extracted from fruits with 61 and 64 days of age after the anthesis; there was a decrease in the germination percentage in the seeds stored in the laboratory environment compared to the seeds stored in the refrigerated environment; the ontogenesis of the seed coat varied at the various stages of maturation.