Prior knowledge about the physiological behavior of seeds under storage conditions allows the use of appropriate techniques to maintain viability. The goal of the present study was to classify the behavior of Simarouba amara seeds regarding their physiological potential during storage. The seeds were obtained from mature fruits, collected from five parent plants located at the Joanes-Ipitanga Environmental Protection Area (EPA) (Simões Filho, Bahia) in January 2018. Two experiments were carried out in a completely randomized design. In the first one, seed desiccation tolerance was evaluated with seven moisture contents: 5%, 7.5%, 10%, 12.5%, 15%, 25% and 35.6% (initial moisture). A germination test was carried out to evaluate the seeds’ vigor. In the second experiment, the seeds were stored with moisture contents of 7.5%, 12.5% and 35.6% at temperatures of 8 °C, 15 °C and 20 °C) for two storage periods, two and four months, and samples were taken to determine moisture content and conduct the germination test. Germination tests were performed in BOD chambers at 30 °C and with 12-hour light photoperiod. Daily counts were performed for the number of germinated seeds. We measured germination percentage, mean germination time, uncertainty index, percentage of normal seedlings, and percentage of unviable seeds. Simarouba amara seeds tolerate desiccation up to 7.5% moisture content, but lost viability when stored under this condition. At four months of storage all seeds lost viability. Simarouba amara seeds are recalcitrant and lose viability before reaching two months of storage.
We investigated the associations of seasonality, dispersal modes and seed germination speeds with the fruiting of Clusia nemorosa, Pleroma fissinervium, and Vochysia pyramidalis in a gallery forest, Chapada Diamantina, Brazil. Observations of mature fruits with dispersing seeds were carried out from 2003 to 2006. Cross-correlation and circular statistics were performed to test the relationships among fruiting and abiotic factors, and phenological seasonality. Dispersion syndromes were defined and germination experiments were performed after seed collection (n =100/species), using four replicates. The species evidenced seasonal fruiting. Clusia nemorosa produced zoochoric seeds and V. pyramidalis anemochoric seeds, which were dispersed during the rainy season and positively correlated with precipitation; P. fissinervium produced autochoric seeds, released during the dry season to early rainy season, being positively correlated with insolation and negatively with humidity. The rotating wing seeds of V. pyramidalis were released in the rainy season and aided floating in watercourses, characterizing hydrochory. Clusia nemorosa and V. pyramidalis germinated (2-6 days) more rapidly than P. fissinervium (9 days). Seasonality, dispersal modes, and optimal germination conditions modulated the fruiting of the species examined, whose reproductive strategies responded to environmental drivers such as precipitation, favoring germination during the rainy season.
Os testes de germinação são ferramentas indispensáveis na caracterização de lotes de sementes. Entretanto, não há prescrição para condução do teste de germinação para sementes de Parapiptadenia blanchetii (Benth.). As informações a respeito da espécie são limitadas a taxonomia e área de distribuição. O objetivo desse estudo foi determinar a duração do teste de germinação para sementes de P. blanchetii, com emprego de regressão segmentada. O experimento foi conduzido nas temperaturas de 20, 25, 30 e 35 °C, e quatro repetições de 25 sementes. A curva de germinação foi ajustada por modelos de regressão response-platô: linear segmentado com platô (MPL) e o quadrático segmentado com platô (MPQ). Para a germinação, o MPQ apresentou o melhor ajuste a 20 °C e 25 °C. No entanto, nas temperaturas de 30 °C e 35 °C o desempenho dos dois modelos foi semelhante. Para a formação de plântulas normais o melhor ajuste dos dados foi no MPQ nas temperaturas de 25 °C e 30 °C, nas demais temperaturas o MPL apresentou melhor desempenho. A duração dos testes de germinação depende do critério de germinação e da temperatura. Para os testes de germinação, realizados em temperaturas de 30 °C ou 35 °C, ao adotar a protrusão radicular como critério de germinação, recomenda-se única contagem no quarto dia após a semeadura. Para avaliar a formação de plântulas normais, sugere-se primeira e segunda contagem, aos seis e nove dias.
This study aims to determine the effect of nursery production time and container size on the quality standards of production of Simarouba amara seedlings based on nursery and field performance. The work was conducted in two phases: evaluation of nursery growth and field performance. A completely randomized design was used in both phases. Three container sizes (55, 180 and 280cm³) and four nursery production times (105, 125, 135 and 145 days) were tested. Height, collar diameter and survival were evaluated. S. amara seedlings can be produced in a 180 cm³ container with a maximum nursery production time of 125 days. The quality standard for seedlings corresponds to collar diameter ≥ 4.2 and height ≥ 9.1 cm.
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