TITLE:
Germination Response of Ornamental Pine Seeds on a Two-Way Thermogradient Plate
AUTHORS:
Marcos Vieira Ferraz, Kathia Fernandes Lopes Pivetta, Hugh W. Pritchard, Tim Marks, Marcelo Vieira Ferraz, Leandro José Grava de Godoy
KEYWORDS:
Thermogradient Plate, Temperature Regime, Germination Percentage
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.1,
January
10,
2018
ABSTRACT: The objective of this study was to evaluate the
effect of temperature on germination of Pinus tabuliformis Carrière seed, Pinus gerardiana Wall. ex D. Don and Pinus roxburghii Sarg. Seeds of three species were distributed in Petri
dishes with 1% agar solution; for the first step it was placed on a 2-way
Grant’s thermogradient plate (a bi-directional incubator) for a period of 28
days and during the second step in an incubator type B.O.D. also for 28 days
with non-germinated seeds in the first step. This instrument allows an
assessment of a wide regime of constant and
alternating temperatures, resulting to 144 different combinations of
temperature, scheduled to the temperatures 4°C - 40°C. The lighting regime was 12 hours
photoperiod for the two stages of the experiment. The best temperature for the
germination of P. tabuliformis was 26.2°C (minimum of 7.9°C and maximum 37.0°C) and P. roxburghii was 15.6°C (minimum 10, 4°C and maximum 37.0°C). The seeds are neutral photoblastic. P. gerardiana showed low germination
percentage (below 10%). The temperature that provided the highest germination
percentage for P. tabuliformis was
26.2°C and 15.6°C for P.
roxburghii.