Repeatability of useful characteristics as morphological descriptors in Cedrela odorata L. clones.

Abstract

There are advances in the genetic improvement of Cedrela odorata in Mexico. The improved material must have distinguishable and stable characteristics when it grows in different places to obtain intellectual property. The objective of this study was to assess the repeatability of morphological descriptors in C. odorata clones whose vegetative reproduction has been more successful by grafting, as superior genotypes can be identified for the registration of their intellectual property. 90 clones produced by grafting at two contrasting evaluation sites (clonal trials) and in a clonal bank were assessed. 19 characters were selected: 12 quantitative and 7 qualitative; related to growth, stem, crown and leaves; only leaves were evaluated in the clonal bank. Most of the characters showed variation coefficients >20 %, which is a high level of phenotypic variability among clones. Principal Component Analysis revealed that the descriptors that contributed significantly and were consistent in the three sites were leaf length and width, petiole length and width of secondary leaflets; in the two trials diameter and straightness of the stem also contributed. The cluster analysis showed little relationship between the morphological characters with the groups of clones and provenances formed in each evaluation site. The clusters formed by the cluster analysis were distinctive at the three sites, and no clones could be consistently discriminated between sites. Genotype by environment interaction and the different rootstock in each ramet could reduce the possibility of repeatability in the characters and the registration of superior clones.