Overcoming dormancy of Pinus pinceana seeds

After several unsuccessful attempts to germinate seed of Pinus pinceana Gordon, seeds from 12 populations in three regions of Mexico were subjected to four treatments (whole seeds, de-coated seeds, de-coated seeds placed on half of their seed coats and cracked seed coat in the micropylar area) to determine the type of dormancy and promote germination in P. pinceana seeds. The germination percentage ranged from 9-86% for whole and de-coated seed, respectively. The speed of germination ranged from a peak value of 0.53 for whole seed to 8.75 for de-coated seed. It was concluded that mechanical restriction imposed by the seed coat and chemical inhibition were the major factors preventing germination. Variation in germination parameters was found to be under strong genetic control. Family variance ranged from 16.5% to 23.7% of the total variance for germination percentage and peak value, respectively.