Journal of Plant Pathology & Microbiology

Inter-specific differences in growth, leaf phenology in seedlings of Quercus suber L., Quercus canariensis Willd and their hybrid (Quercus afares Pomel) grown in the nursery

International Conference on Plant Physiology & Pathology

June 09-10, 2016 Dallas, USA

Sameh Mhamdi

French National Institute for Agricultural Research, France

Posters & Accepted Abstracts: J Plant Pathol Microbiol

Abstract:

Outside of the systematic, leaf longevity (Leaf lifespan) is used to classify trees into two main groups: evergreen and deciduous species. It varies significantly according to the forms of life between taxonomic groups and the long succession gradient. Co-occurrence of winter-deciduous and evergreen oaks is common in some Mediterranean type climate areas. Nevertheless, in the Tunisian forests, we don�??t have enough information about the functional inter-specific diversity among oak species, particularly in the mixed stand marked by the simultaneous presence of cork oak (Quercus suber L, evergreen oak), zeen oak (Quercus canariensis Willd., deciduous oak) and their putative hybrid (Quercus afares Pomel, deciduous), endemic oak species threatened with extinction. This study has been designed to estimate the leaf lifespan, the relative growth rate in height (RGRH) and in basal diameter (RGRBD), and the count of different growth flushes in samplings in semi-controlled conditions (nursery), it made at 4 weeks interval and observations on each plant over 17 months. The aim is to better characterize and compare the hybrid to the co-occurring parental species for these functional traits. Differences were observed between parental species and their hybrid, both at growth and phenology. Indeed, Q. suber saplings reached higher total height and number of growth flushes (7 flushes per year) then saplings of Q. canariensis had established an average of 5 flushes per year, while Q. afares individuals showed much less growth flushes (2 units per year) and are the less performing specie. Also, the leaf lifespan of seedling of two species (Q. suber and Q. canariensis) has exceeded the duration of the experiment on most of cohorts, but their hybrid (Q. afares) lost all leaves on all cohorts. The shorter leaf lifespan of Q. afares is in accordance with its phenology in the field but for Q. canariensis the long leaf lifespan contrast with observations for adult trees in the field where phenology is strictly annual. This study allowed us to differentiate the hybrid Q. afares of both parental species through the characterization of growth and leaf lifespan at seeding stage.

Biography :

Email: samehmhamdi2006@yahoo.fr