Marlove Fátima Brião Muniz

Efeito da luz, temperatura e estresse hídrico no potencial fisiológico de sementes de funcho

The objective of this study was to evaluate the effects of light, temperature and hydric stress on the germination and vitality of fennel seeds.. First, the seeds were sowed on paper at constant temperatures of 20, 25, 30oC or alternating temperatures of 20-30oC in the presence or absence of light. In a second step, seeds were kept on paper in aqueous polyethylene glicol (PEG 6000) at the osmotic potentials equivalent to zero; -0,05; -0,10; -0,15; -0,20; -0,25;-0,30MPa. According to the results, it was possible to conclude that germination of fennel seeds occurred in presence or absence light. The fennel seeds germinated better at constant temperatures of 20 and 25oC but 30oC was not useful for the germination test. The decrease in the osmotic potentials reduced the germination and vigor of fennel seeds, and vigor was more affected than germination. The germination was drastically reduced, starting at -0,1 MPa for fennel when there was a decrease in the osmotic potentials with polyethylene glicol 6000.

Fungos antagonistas a Sclerotinia sclerotiorum em pepineiro cultivado em estufa

White mold caused by Sclerotinia sclerotiorum may severely damage vegetables grown in greenhouses. To develop a biological control program for this pathogen proper antagonists are needed. This work aimed to select efficient fungi antagonists for controlling S. sclerotiorum on cucumber (Cucumis sativus) grown in greenhouses, and to evaluate the effect of the antagonist on the growth of the vegetable. An isolate of S. sclerotiorum obtained from cucumber and 112 fungi isolates belonging to four genera were used: Trichoderma, Fusarium, Penicillium, and Aspergillus. For the in vitro experiment, the cellophane method was used and eight Trichoderma virens isolates were selected that had inhibited the pathogen growth by 94 to 100%. Greenhouse experiments used sterilized and non-sterilized substrate in plastic cups and non-sterilized substrate in plastic bags. The substrate was inoculated with S. sclerotiorum and the eight isolates of T. virens were used as antagonists. All eight isolates controlled damping-off of plants caused by S. sclerotiorum, but the effect on cucumber growth varied according to the isolate and the substrate treatment.

Avaliação da qualidade de sementes e mudas de cedro.

Belonging to the Meliaceae family, cedro ( Cedrela fissilis Vell.) presents a great economical and ecological importance. The wood is light and easy to work, being suggested to the manufacturing of furniture in general, also it is used to reset degraded areas. The objective of this work was to evaluate the quality of Cedrela fissilis seedlings and seeds from Rio Grande do Sul, Santa Catarina and Parana, through the accomplishment of varied tests of vigor, test of health and evaluation of the quality of seedlings produced from these seeds. The present study showed that the presence of fungi pathological potential – Aspergillus spp. and Penicillium spp. – can cause losses in the germination. Considering tests with seeds collected in the different states of the South Region, it was possible to verify that differences of the vigor levels exist. The fungi found in the seeds can cause damages in the production.

Influence of packaging on physiological quality of maize seeds

This study aimed to evaluate the physiological quality of maize seeds of six varieties submitted to the storage in plastic packaging and cloth bags. The moisture content, germination, germination first count, emergence, speed emergence rate, length and dry weight of seedlings were evaluated. During the six months of storage, the seed moisture content did not exceed 13%. The germination and emergency was reduced in both packagings, and in the plastic packaging, the reduction was due to the removal of oxygen from inside the package, while for the seeds stored in cloth bags, it was because of infestations of insect pests and increasing incidence of fungi due the ambient conditions during storage. The varieties performed differently regarding the physiological parameters of quality seeds, depending on the packaging used. The length and dry mass in the two types of storage presented values near or above the initial condition at the end of six months. The maintenance of maize seed physiological quality during storage depends on the variety and type of packaging.

Envelhecimento acelerado em sementes de azevém com e sem solução salina e saturada

The objective of the present study was to evaluate the methodology of the accelerated aging test to evaluate the physiological potential of s ryegrass seeds, as well as verify the possibility of the use of unsaturated and saturated solution of NaCl as an option for control of water uptake by seeds during the test without reducing its sensitivity. Four lots of ryegrass seeds were tested for germination, seedling emergence, speed emergence and accelerated aging (periods of 24, 48, 72 and 96h, with or without the use of saturated and saline solution of NaCl). The use of unsaturated and saturated solution of NaCl reduces water absorption by ryegrass seeds during the accelerated aging test, resulting in a rate of deterioration is less pronounced ,less drastic and more uniform results. Option 24h with unsaturated solution (SNS) was only able to stratify plots into two groups and should not be designated as promising. Thus, it should be used the 48h saturated NaCl solution (SSS), which stratified into three lots.

Superação de dormência na qualidade de sementes e mudas: influência na produção de Senna multijuga (L. C. Rich.) Irwin & Barneby

The objective of this work was to determine the physiological and sanitary quality of Senna multijuga seeds related to the methods of dormancy overcoming and the influence on the seedlings quality. The seeds had been submitted to the following methods :immersion in water fervent, the seeds had been immersed in water, at 100°C, until cooling for 24 hours; acid escarification, where the seeds had been immersed in sulfuric acid (H 2 SO 4 ) 90%, for 10 and 20 minutes, and control (without treatment). The tests of sanity, germination and tetrazolium had been carried through, and were evaluated the quality of the seedlings. For the germination of the evaluation an factorial project was used (4 X 2), with four methods of dormancy X two light periods, for substrate paper and vermiculite. The acid scarification consisted in the method most efficient for the dormancy of Senna multijuga seeds. Penicillium sp. and Aspergillus sp. they had for its increased incidence when the seed coast was damaged by the acid scarification for 20 minutes. The control of Fusarium spp. increases gradual with the increase of the time of sulfuric acid exposition.

Qualidade de sementes de milho armazenadas em diferentes embalagens

The storage is a decisive part of seed production of high quality. The objective of this study was to evaluate the physical, physiological and sanitary quality of three maize varieties seeds, stored for six months in plastic packaging and cotton bags. Germination, quantification of insect damage and seed health were evaluated. In the plastic packaging storage, were observed reduction in the germination, but the presence of insect pests was lower. The storage in cotton bag reduced the seeds quality, due to the presence of insect pests and the high incidence of Fusarium, Penicillium and Aspergillus. The storage in plastic package provided the maintenance of seeds quality, with a lower incidence of insects and fungi when compared to the cotton bags. The varieties showed different answers in relation to the packages used.

Maturação fisiológica e coleta de sementes de Eugenia uniflora L. (Pitanga), Santa Maria, RS.

This study aimed to accompany the physiologic maturation, their indicative parameters and to identify the moment adapted for the seed harvest of Eugenia uniflora , evaluating also the incidence of fungus in fruits and seeds. The research was carried out from August to October of 2004 in Santa Maria, RS. Samples of fruits and seeds were collected weekly, from three main trees, with beginning to the seven days after the anthesis (DAA) and end to the 77 DAA. The observed variables were: length, diameter, weight and sanity of fruits and seeds and moisture content, dry mass and germination of the seeds. The appropriate time for the seed harvest, in the period and place being studied, occurred between 56 and 63 DAA, when the fruits presented red coloration and the seeds high germination. In that period, the size and the weight of fruits and seeds reached their maximum values and the moisture content and dry mass of the seeds showed tendency to the stabilization. The fungi Cladosporium sp. and Alternaria sp. presented the largest incidence taxes in the fruits and in the seeds and they can influence the storage and the germination Eugenia uniflora seeds.

Qualidade sanitária e fisiológica de sementes de abóbora variedade menina Brasileira.

ABSTRACTHealth and Physiological Quality of ‘Menina Brasileira’ Squash Seeds The objective of this work was to evaluate and correlate the health and physiological qualities of squash seeds of the variety Menina Brasileira (Cucurbita moschata.). We evaluated two squash seed lots produced in the agroecological systemWe evaluated two squash seed lots produced in the agroecological system and four seed lots produced in the conventional system with and without chemical treatment. The seed lots were submittedThe seed lots were submitted to health tests with freezing, germination and vigour, following Blotter test methodology (first count, germination speed, accelerated ageing and seedling emergence tests). The results from the health and physiological tests indicated a difference between seed lots from different origins: the agroecological lots showed the highest incidence of fungi and the conventional lots without chemical treatment showed the highest physiological potential. The fungiThe fungi Fusarium oxysporum, Alternaria alternata, Cladosporium cucumerinum, Aspergillus niger, Penicillium digitatum, Rhizopus stolonifer and Phoma terrestris were found to be associated with seeds. The health quality did not interfere with the physiological quality of the ‘MeninaThe health quality did not interfere with the physiological quality of the ‘Menina Brasileira’ squash seeds.

Detection, transmission, pathogenicity and chemical treatment of fungi in Ceiba speciosa seeds

Neste trabalho avaliou-se a incidencia, transmissao, patogenicidade de fungos e a eficiencia do tratamento quimico no controle dos mesmos em sementes de paineira (Ceiba speciosa) oriundas de diferentes locais do sul do Brasil. Para tanto, utilizaram-se sete amostras de sementes, com as quais realizaram-se testes de germinacao, sanidade empregando-se o metodo do papel-filtro (PF) e de plaqueamento em batata-dextrose-agar (BDA), transmissao e patogenicidade dos fungos e tratamento quimico das sementes. A germinacao variou de 0 a 59,5%. Foram detectados os seguintes fungos associados as sementes: Fusarium sp., Alternaria sp.,Colletotrichum sp., Curvularia sp. e Pestalotia sp.; sendo que Fusarium sp. foi encontrado em todas as amostras. Ambos os metodos de deteccao, PF e BDA, foram eficientes na deteccao da maior parte dos fungos. Alternaria sp. e Fusarium sp. foram transmitidos via sementes. Os isolados de Alternaria sp., Colletotrichum sp. e Fusarium sp. foram patogenicos as plântulas e os tratamentos das sementes com tiofanato metilico e a mistura captan + tiofanato metilico reduziram a incidencia de Fusarium sp.