Morphological characterization of seeds and germination of Pseudotsuga menziesii (Mirb.) Franco (Pinaceae)

Pseudotsuga menziesii (Mirb.) Franco is a species of economic and ecological importance for Mexico. Several actions have been implemented for its ex situ conservation. However, the lack of characterization data is a limiting factor in genebanks. In this study, morphological characteristics and seed germination traits were evaluated in 12 accessions of P. menziesii from Tlaxcala and Puebla. Fifteen seed variables, germination percentage (PG), days to germination (DG) and radicle growth (CR) were measured in 100 seeds (four replicas of 25 seeds each) per accession. A principal component analysis, a cluster analysis and the estimation of the relationship between seed variables and germination traits were performed. The variables that had largest influence on the distribution of morphological variation were: LA, ASC, AS and AA/AS. The accessions were distributed in five general groups according mainly to their geographical origin. For some accessions, PG and CR had a direct relationship with seed size variables. These results showed the presence of variation and the influence of seed morphology on the germination of the evaluated accessions.