ABSTRACT
In assessing the quality of seed lots, the vigor tests are complementary to the germination test and they identify differences in the degree of deterioration of the lots. For safflower, there is little information regarding these tests. In this way, the intention of this study was to adapt the accelerated aging test methodology to assess the physiological potential of safflower seeds (Carthamus tinctorius). For this purpose, 12 seed lots were evaluated for thousand-seed weight, germination, first germination count, seedling emergence test (emergence percentage, emergence speed index, relative emergence frequency and the initial, final and mean times) and accelerated aging. For the accelerated aging test, the traditional and saline methods were used. For this, the samples were conditioned in periods of 0, 8, 16, 24, 32 and 48 hours at 42 °C. Afterwards, they were submitted to the germination test, with evaluation of normal seedlings on the 3rd day. The 12 lots were evaluated within each period, in independent experiments. The data were submitted to analysis of variance and the means were compared using the Scott-Knott clustering method at 5% probability. In the traditional accelerated aging test the periods of 16, 24, 32 and 48 hours were more efficient in differentiating the lots in vigor levels, as they stratified the lots in three classes and the time of 8 hour classified the lots in two levels of vigor. In the accelerated saline aging method the time 32 hours were more efficient since it ranked seed lots at three levels of vigor and the periods of 8, 16 and 24 hour stratified the lots in two levels. In results obtained by the principal component analysis it was verified. The variables traditional accelerated aging for 24 and 32 hours correlated with emergence in the field. Therefore, the traditional accelerated aging test at 42 °C for 24 hours are promising for evaluating the physiological quality of safflower seeds.
Subject(s)
Plant Physiological Phenomena , Carthamus tinctorius/physiologyABSTRACT
ABSTRACT: The gabirobeira is a species native to the Brazilian Cerrado with potential for use in cropping systems. This study evaluated the effect of the cytokinin 6-benzylaminopurine (BAP) on root cuttings of gabirobeira (Campomanesia adamantium). The plant material was obtained from gabirobeira progenies of one and two-years-old. The cuttings were segmented in 5 cm length and 1.90 to 3.22 mm diameter, immersed in the following BAP concentrations: 0.0; 1.0; 2.0 and 4.0 mg L-1 for 15 seconds and planted in trays containing the substrate Bioplant®. A complete randomized experimental design was adopted in a factorial scheme 2x4, (cuttings age x BAP concentrations) with fifteen replicates per treatment. After 140 days the number of cuttings with shoots, number of shoots, number of leaves, and diameter of the main root were evaluated. The better development of the cuttings was observed on progenies of two-years-old. The lowest cytokinin concentrations promoted the better emission and number of shoots of the progenies from both ages.
RESUMO: A gabirobeira é uma espécie nativa do Cerrado brasileiro com potencial para uso em sistemas de cultivo. O objetivo deste estudo foi avaliar o efeito da 6-benzilaminopurina (BAP) em estacas radiculares de progênies de Gabirobeira (Campomanesia adamantium). As estacas radiculares foram obtidas de progênies de Gabirobeira de um e dois anos de idade. Estes foram segmentados em 5 cm de comprimento e apresentavam entre 1,90 a 3,22 mm de diâmetro, imersos nas concentrações: 0.0; 1.0; 2.0 e 4.0 mg L-1 de BAP por 15 segundos e plantados em bandejas contendo Bioplant®. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2x4 (idades das estacas x concentrações de BAP), com quinze repetições por tratamento. Após 140 dias, foram avaliados o número de estacas com brotações, número de brotações, número de folhas e diâmetro da raiz principal. Estacas de raízes de progênies de dois anos de idade apresentaram melhor desenvolvimento. Menores concentrações de citocinina trouxeram melhores resultados de emissão e número de brotações das progênies de ambas as idades.
ABSTRACT
ABSTRACT The present study reports a shoot organogenesis-based system for in vitro regeneration of Passiflora miniata, an Amazonia passion fruit species. Root segments were cultured in Murashige and Skoog (MS) medium supplemented with different concentrations (range 2-9 µM) of 6-benzyladenine (BA); thidiazuron (TDZ) or kinetin (KIN). Plant growth regulators were not added to the control treatment. Root explants have showed a high regenerative potential. After 30 days of in vitro culture, the root explants showed several shoots formed direct and indirectly. TDZ provided the best response in the differentiation adventitious shoots, mainly in the presence of 6.8 µM. The cytokinins BA and KIN responded producing a reduced number of shoots. After 120 days, rooted regenerated plants were transferred to a greenhouse for acclimatization. This regeneration system opens new perspectives for micropropagation and conservation of this wild Amazonic passion fruit species.