RESUMO No presente trabalho, o objetivo foi adequar a metodologia do teste de envelhecimento acelerado para avaliação INTRODUÇÃOO coentro (Coriandrum sativum L.) é uma hortaliça folhosa muito utilizada na culinária brasileira, em especial na região Nordeste do Brasil, sendo uma cultura de grande rotatividade comercial. A qualidade das sementes utilizadas pelos agricultores está relacionada de forma direta ao seu potencial fisiológico, representado pela germinação e vigor, expressando sua capacidade de originar plântulas normais (PEREIRA et al., 2011).Para determinar o potencial germinativo de um lote de sementes, utiliza-se o teste de germinação, porém, esse teste, isoladamente, não determina a efetiva qualidade da semente, dessa forma, os testes de vigor fornecem informações complementares, que permitem detectar diferenças fisiológicas para lotes de mesma porcentagem de germinação. Dentre os testes utilizados e também considerados como um dos mais sensíveis para a avaliação do vigor de sementes destaca-se o teste de envelhecimento acelerado (MARCOS FILHO, 1999), uma vez que seus resultados se relacionam com o potencial de conservação das sementes.Um aspecto de grande relevância a ser considerado no teste de envelhecimento acelerado é o tamanho da semente, pois, segundo RAMOS et al. (2004), para espécies de sementes relativamente pequenas, como as de hortaliças, tem-se obtido resultados menos consistentes, devido à variação muito acentuada no grau de umidade ao final do I

-Chia cultivation is expanding in Brazil, but there is still no standardized test to evaluate the quality of the seeds. Therefore, vigor tests that expose seeds to stress conditions must be standardized. This study aimed to establish the methodology for the accelerated aging test in chia seeds. Six chia seed lots with similar germination behavior were used. They were submitted to germination, first germination count, seedling emergence, emergence speed index and accelerated aging tests. Aging periods of 24, 48, and 72 hours were used in the conventional methodology, and also with the use of unsaturated and saturated sodium chloride (NaCl) solutions. The results obtained from the accelerated aging tests revealed tendencies for lot separation similar to the classification of chia seed lots in relation to the physiological potential obtained in the preliminary quality tests. The accelerated aging test can be used to evaluate the physiological potential of chia seeds by using water or unsaturated saline solution. In the conventional test (water), the seeds should be exposed for 24 hours. When using unsaturated saline solution, the exposure time must be of 48 hours.

No abstract

Ryegrass (Lolium multiflorum Lam.) is forage with the potential to increase pasture area in Southern Brazil. It is an option for more profitable and intensive use of floodplain areas during the cold seasons of the year. However, irrigation of crops in these areas in the summer can result in the salinization of the soils that have inadequate drainage, preventing the removal of salt by leaching. The objective of this study was to evaluate the performance of ryegrass seeds using different concentrations of sodium chloride. Four commercial ryegrass cultivars of PGG Wrightson Seeds Brazil were used: Inia Bakarat, Inia Scorpio, Inia Camaro, and La Estanzuela 284. Saline substrates consisted of Germitest® paper wetted with sodium chloride solution at five osmotic potentials (0, -0.2, -0.4, -0.6 and -0.8 MPa). The study was conducted at the "Flavio Rocha" Didactic Seeds Analysis Laboratory and involved analysis of the following indicators of salt stress response: germination (%), first germination count (%), plantlet length (cm), and plantlet dry phytomass (mg/seedling). The results showed that saline stress conditions caused by reduced osmotic potential affected ryegrass seed germination and vigor, as well as decreased the stature of the aerial and root parts of the seedlings. Out of the cultivars evaluated, La Estanzuela 284 was the most tolerant to saline stress. It is possible to cultivate ryegrass in areas with salinity up to mean values of -0.2 MPa osmotic potential. In this study, no significant decrease in seedling performance was observed.

ABSTRACT:The objective was to evaluate the effect of seed wheat coated with zinc, in its physiological, sanitary attributes and enzyme quality, during storage. We used two batches of seed, for seed treatment, we used commercial product as a source of zinc in the form of ZnSO 4 , along with fungicide and polymer. It was tested for levels 0, 1, 2, 3 and 4 mL ZnSO 4 kg -1 seed. The physiological quality, during the storage period, was analyzed by the tests: moisture content, hectoliter weight, germination, emergence, index emergence rate, tetrazolium and sanity test. It was concluded that the doses 3 mL and 4 mL of ZnSO 4 to assist in the ultimate expression of the seeds physiological quality, until six months stocked. This coating promotes a smaller reduction in the viability of seeds, furthermore, results in a lower incidence of fungi on seeds during storage. Also help to maximize the expression of physiological seed quality of higher and lower quality, respectively. The micronutrient zinc associated with fungicide and polymer had a lower incidence of fungi during the storage period.

The physiological performance of seeds is related to their physiological quality and seed vigor, while their health quality may interfere with germination and early seedling establishment in the field due to the interaction of microorganisms associated with seeds. The study aimed to evaluate the physiological performance and health quality of cucumber seeds and to verify the relationship between these attributes. The physiological quality of cucumber seeds was evaluated by standard germination tests, first count of germination, controlled deterioration test, electrical conductivity test, seedling emergence, emergence speed index, and traditional accelerated aging and aging modified with saline for 48, 72, and 96 h. The health quality of cucumber seed lots was evaluated by blotter test. Stratification of cucumber seed lots by seedling emergence was similar to seedling emergence by controlled deterioration test, first count of germination, and electrical conductivity results. The cucumber seed lots evaluated showed high germination rates; however, lots 1 and 3 had a better performance in vigor tests than lots 2 and 4. Fungi detected in the blotter test were Alternaria sp., Aspergillus sp., Cladosporium sp., and Penicillium sp. Seed lots 2 and 4 had low vigor evaluated by seedling emergence and controlled deterioration, and showed a higher incidence of Penicillium sp. in the evaluation of health quality of seeds. The incidence of Penicillium sp. may negatively affect the vigor of cucumber seeds evaluated by seedling emergence and by controlled deterioration test.

-This study aimed to evaluate, at 15, 20 and 25 ºC, the physiological potential and enzyme activity of seedlings from six samples of rice seeds stored for one year and treated with growth-promoting rhizobacteria (Pseudomonas synxantha) and the bioactivator thiametoxam. The following were evaluated: seed germination, first germination count, root protrusion speed index, emergence percentage and emergence speed index, shoot and root length and enzyme activity (esterases, α-amylase and peroxidases) at 15, 20 and 25 ºC. In these conditions, thiametoxam and the rhizobacteria P. synxantha (DFs 185) improved the physiological performance of rice seeds with physiological qualities at low temperatures (20 and 15 ºC) and did not change the expression of the esterase and peroxidase isoenzymes. The rhizobacteria P. synxantha (DFs 185) increased the expression of the enzyme α-amylase at low temperatures.

Lavender, an aromatic and medicinal plant, used in the extraction of essential oil, as an ornamental and meliferous plant, can be successfully propagated as long as the light, the nutrient medium and the growth regulators are adequate. The aim of the study was to evaluate the effect of different concentrations of indolebutyric acid (IBA) associated to distinct light spectra, on the in vitro rooting of Lavandula angustifolia. The experiment consisted in the combination of two concentrations of indolebutyric acid in the growth medium (0 and 0.1 mg L-1) and two light spectra, using cellulose acetate filters (blue and red), besides the control (without filter), totaling six treatments with four repetitions. For each repetition five explants were used. After 30 days, the variables evaluated were: survival percentage, number of buds and leaves, shoot length, number of roots, length of the longest root, shoot fresh and dry matter weight. There was a significant interaction among the indolebutyric acid concentrations and the light filters for the variables number of buds, leaves and roots and shoot length. Except for leaf number, promising results were obtained when the explants were held under red filters and with a concentration of 0 mg L-1 of indolebutyric acid in the growth medium. From these results, it can be concluded that the best in vitro rooting of Lavandula angustifolia is obtained when there is no indolebutyric acid in the growth medium associated with the use of the red filter.