Inter-specific differences in architectural and morphological traits on seedlings of cork oak (Quercus suber L.), zeen oak (Quercus canariensis Willd.) and their hybrid afares oak (Quercus afares Pomel) growing in the greenhouse

Abstract: The genus Quercus L. has a problematic taxonomy because of widespread
hybridization among them. Its shows highest morphological variations among species and
populations (Kremer and Petit, 1993). This study is part of a general research work on the
characterizations and variabilities of two co-occurring Quercus species – one deciduous
(Quercus canariensis Willd.) and one evergreen (Quercus suber L.) and their hybrid Q. afares (deciduous). Quercus afares is an endemic species in Tunisia and Algeria, and it is rated as vulnerable in oaks species, although there are only few studies about this species compared to parental species. In this work, we have studied the interspecific differences in some morphological traits related to seedlings of this species regarding parental species, by
quantification of total number of leaves, ramification number, flush number and chlorophyll
concentration (SPAD) in 90 seedlings from the three species growing in a greenhouse under
optimal conditions. The significance of the differences among species for each trait were
evaluated through one way analysis of variance using average value using SPSS software, and
species pairwise comparisons were performed with Tukey post hoc tests at the P < 0.05
significance level. The results showed a significant variation between the three species; the
most significant differences of hybrids were found between Q. suber and Q. afares than between Q. canariensis and Q. afares. However, Q. suber and Q. canariensis remained distinct for all traits. The hybrid was separated from the remaining species for flush number and the SPAD. Quercus suber showed the higher means for the number total of leaves, ramification number while the higher average for flush number. Results obtained in this study demonstrate the usefulness of morphological, architectural, and functional traits in delimitation of hybrid species and its parental species.