• Slow-grown in vitro conservation of Heliconia champneiana cv. Splash under different light spectra Note

    Rodrigues, Paulo Hercílio Viegas; Arruda, Flávia; Forti, Victor Augusto

    Abstract in English:

    ABSTRACT: In vitro techniques, with the purpose of conserving the genetic resources of plants, are fundamental to the feasibility of establishing germplasm banks and enabling the commercial production of micropropagated plants. The aim of this study was to evaluate the use of different spectra of light in in vitro germplasm conservation by slow grown storage of Heliconia Champneiana cv. Splash. Explants of heliconia in vitro were submitted to the following light treatments: CW (control white), B100 (100 % blue), R100 (100 % red) and R70B30 (70 % red/30 % blue), all with PFD = 25 μmol m2 s–1, maintained in vitro for two time periods, namely P1, 6 weeks and P2, twelve weeks, and were statistically evaluated after each interval with respect to: height, fresh weight, number and length of roots, number of leaves, and pseudostem diameter, in addition to the rate of acclimatization in percentage terms. Treatment B100 presented the lowest level of development in the two periods, and 100 % survival in acclimatization.
  • Vigor-S, a new system for evaluating the physiological potential of maize seeds Note

    Castan, Danielle Otte Carrara; Gomes-Junior, Francisco Guilhien; Marcos-Filho, Julio

    Abstract in English:

    ABSTRACT: The refinement of vigor tests and the possibility of utilizing computer resources for the effective evaluation of the seed physiological potential have attracted considerable interest from research and seed technologists. The aim of this study was to evaluate the physiological potential of maize seeds using the newly-created Automated Analysis of Seed Vigor System (Vigor-S) compared with other recommended seed vigor tests; two maize hybrids were used, each represented by seven seed lots. Germination and vigor (cold test, saturated salt accelerated aging, and field seedling emergence) evaluations were conducted. For the evaluation of seed vigor with the use of seedling image analysis resources, two systems were compared: the Seed Vigor Imaging System (SVIS®), developed by Ohio State University, USA and the Vigor-S, resulting from collaboration between USP/ESALQ and EMBRAPA (Embrapa Instrumentation). Using these two systems, three day old seedlings were scanned and the images were analyzed. Similar results for the vigor index, uniformity of development, and seedling length were obtained. The computerized image analysis of seedlings using Vigor-S has advantages with respect to accuracy, speed, and the possibility of automatic application to a worksheet. It is a consistent alternative for the evaluation of maize seed vigor, and produces information compatible with that obtained by the accelerated aging test and SVIS®.
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