Cibele Chalita Martins

Temperatura e substrato para o teste de germinação de sementes de pinhão-manso

Nao existem criterios para a execucao de testes de germinacao para sementes de pinhao manso publicados nas normas oficiais para analise de sementes. Assim, objetivou-se com esta pesquisa determinar o substrato, temperatura e tempo de contagem para o teste de germinacao de sementes de pinhao-manso. Para o teste de germinacao utilizaram-se quatro repeticoes de 20 sementes, contabilizando-se diariamente as plântulas normais ate que a germinacao cessasse. Inicialmente, foram avaliados os substratos em semeaduras entre vermiculita, em rolo de papel, entre areia e entre solo na temperatura alternada 20-30oC. Os substratos mais favoraveis a germinacao foram avaliados numa etapa seguinte, nas temperaturas constantes de 25, 30 e 35°C e alternadas de 15-35°C; 20-35°C e 20-30°C. Concluiu-se que o teste de germinacao de sementes de pinhao-manso deve ser realizado na temperatura alternada 20-30oC, em substrato areia ou papel e com contagem final aos 10 dias da semeadura.

Pre-germinative treatments for inaja palm seeds

Studies were carried out to evaluate inaja (Maximiliana regia Mart.) seed germination promoters. Several treatments, including vernalization, KNO3, H2SO4, hot water (H20-80°C), were applied to mature and imature fruits. The results showed that pre-germinative treatments, that promoted seed water uptake, contributed to enhance speed and germination rates. Among the treatments, unshelled of the fruits could be indicated. It was observed that inaja seeds were aparently recalcitrants and severely damaged by storage conditions which do not prevent dehydration.

TRATAMENTOS PRÉ-GERMINATIVOS E PROCEDÊNCIA DE SEMENTES DO TUCUMÃ-DO-AMAZONAS PARA A PRODUÇÃO DE MUDAS 1

Rapid, uniform seed germination followed by prompt seedling emergence are highly desir- able characteristics in seedling production. The aim of this study was to evaluate the effect of seed origin, frequency with which hydration water was changed and thermal shocks on germination and production of tucuma-do-amazonas (Astrocaryum aculeatum) seedlings. Fruits were obtained from three locations in the state of Amazonas: Manaus market, and in Maues and Taruma-acu. After cleaning and drying the endocarps and removing them, the seeds were soaked for 15 days, changing the water once or twice a day. After soak- ing, the following treatments were applied: control without immersion in H 2 O, immersion for 5 minutes in H 2 O at 50°C or 10°C; immersion for 5 minutes in H 2 O at 50°C, followed by a further 5 minutes at 10°C; immersion for 5 minutes in H 2 O at 10°C, followed by a further 5 minutes at 50°C. Treatments were evalu- ated by pre-germination, seedling emergence in the nursery and seedling production. The experiment was conducted in totally randomized design with treatments arranged in a factorial 3 x 2 x 5 (places of origin x water exchange frequency x temperature treatments) in four replications of five seeds per plot. Germination performance was not affected by the water exchange frequency, nor by exposure to thermal shocks. The origin of tucuma-do-amazonas has effect over the germination and seedling production. Index terms: Astrocaryum aculeatum, germination, soaking.

Isoenzimas no monitoramento da deterioração de sementes de Euterpe espiritosantensis Fernandes

Red-palmito Euterpe espiritosantensis Fernandes seeds are recalcitrants because they exhibit germination decreases by dehydration and have short longevity. The objective of this work was to identify efficient enzymatic systems to monitoring deterioration and loss of germination capacity of red-palmito seeds. Seeds were dryed during 0, 20, and 40h (resulting moisture content of 46, 40 and 36%, respectively) and stored at 15oC, inside closed plastic bags, during 54 weeks. The seed quality was evaluated, in six weeks intervals, by germination test and by enzymatic activity of glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, phosphoglucomutase, phosphoglucose isomerase and peroxidase, using the electrophoresis technique in polyacrylamide gel. The isoenzyme peroxidase was the unique efficient way to monitor deterioration and loss of germination capacity of red-palmito seeds.

Tipos de substratos para germinação de sementes de palmeira- real-australiana (Archontophoenix alexandrae H. Wendl. & Drude)

The objective of this work was to evaluate germinative performance of king palm seeds in different substrates and to set appropriate particle size and moisture for this substrate. Sowing was done with for replications of 25 seeds in soil, sand, paper rolls, and vermiculite of different size: micron (0.15-0.20mm), superfine (0.21-0.30mm), fine (0.30-0.50mm) and medium (1.19-0.50 mm) moistened with 0.5, 1.0, 1.5 and 2.0 times its weight in water. Germination test was carried out at 20-30°C, evaluating the first test count seven days after sowing and germination was evaluated weekly until 35 days, when abnormal seedlings and dead seeds were also counted. Germination average time and relative frequency were calculated. Micron vermiculite moistened with 1.0 times its weight in water presented the best performance as substrate for germination test of king palm seeds because it possibilities maximum germination of seeds (90%) and germination rate, requiring an average time of 15.3 days in this process.

Morphoanatomy of Myracrodruon urundeuva Fr. All. seedlings submitted to different levels of water in the soil

Myracrodruon urundeuva Fr. All. is a medicinal plant of the Caatinga biome, in brazilian northeast. This region is characterized by prolonged dry periods but little is known about the plants mechanisms to tolerate low water availability during their initial phase of growth and establishment seedling. The objective of this project was to evaluate morphological and anatomic characteristics of M. urundeuva seedlings submitted to different water levels in the soil. In a first experiment, the diaspores were sown in trays containing soil taken from the place of occurrence of the species. The substratum was moistened with water to reach 10 to 60% of the soil water retention capacity, with 5% intervals. In a second experiment, the diaspores were sown in the substratum kept at 60% of its water retention capacity for 15 days for the total seedling emergence since this is the most favorable condition for the species as identified during the first phase of this experiment. After that period, plant watering was suspended and the seedling kept in substrata at 60, 30, 25, 20, 15, and 10% of their water holding capacity for an additional period of 10 days, both experiments performed in protected environment. The increasing reduction in water availability led to a reduction in the number of leaves, the leaf area and leaflet thickness, the number of stomata in the leaf and in the cotyledon, the root length and the diameter of the central root. Characteristics such as the stem length, length, width and thickness of the cotyledon were not modified by the