c8.12.16 – Phenotypic plasticity of bud set process in a P. nigra full-sib family

Fabbrini F (1), Gaudet M (1), Harfouche A (1), Bastien C (2), Beritognolo I (3), Scarascia Mugnozza G (4), Sabatti M (1)

(1) Department for Innovation in Biological, Agro-food and Forest systems, University of Tuscia, Via S. Camillo de Lellis, 01100 Viterbo, Italy.; (2) Laboratory of Breeding, Genetics and Physiology of Forest Trees, National Institute for Agricultural Research, BP 20619, Ardon, 45166 Olivet Cedex, France.; (3) Institute for Mediterranean Agriculture and Forest Systems, National Research Council, Via Madonna Alta, 06128 Perugia, Italy.; (4) Department of Agronomy, Forestry and Land use, Agricultural Research Council, Via del Caravita, 00186 Roma, Italy.
Collocazione: c8.12.16 – Tipo Comunicazione: Poster
8° Congresso SISEF *
Sessione 12: “Poster” *

Contatto: Francesco Fabbrini (f.fabbrini@tiscalinet.it)

Abstract: Among forest trees, poplars are important components of riparian ecosystems and are now accepted by the scientific community as ideal model to study perennial plants. They offer several advantages as a model system, including rapid growth, ease of cloning, prolific sexual reproduction, small genomic size and facile transgenesis. In poplar, perception of critical night-length signal leads to apical bud set even if studies showed that the timing of bud formation is also influenced by other factors such as temperature, nutrition and drought. A new protocol has been proposed recently to dissect the growth cessation in poplar and bud set key traits (phase, duration, sub-period) were defined to better characterize the bud set process dissecting the contribution of the different phenological traits to the dynamics of bud set. Besides, the role of phenotypic plasticity as a source of variability to determine short- and long-term plant response in different environments, can be used to evaluate the possibility of temperature-mediated plasticity in climate change scenarios. In the present study, the genetic variability and the broad-sense heritability have been examined in a P. nigra full-sib family (POP5) planted in two experimental trials in central (Viterbo; 42°25’N, 12°05’E) and northern (Cavallermaggiore; 44°42’N, 07°40’E) Italy. Genotype by site (G×S) interaction and phenotypic plasticity were also detected. Results showed that the different phases, especially the onset of growth cessation (phase 2.5), provide the higher contribution to the genetic variance. Duration of traits appears to be highly influenced by the environmental factors, especially the duration of bud formation (duration of subprocess 1) that might be particularly important in the adaptation to short term fluctuations of temperature. A Gaussian distribution and transgressive segregation for all phenological phases were observed in P. nigra pedigree in both sites. Taking advantage of two contrasting environments, we found that temperature, one of the most contrasting environmental variables between the study sites, seems to influence the sensitivity only of the most plastic genotypes within pedigree. The general classification of genotypes was mainly maintained at the onset of the process due to the more important “scale change” effect in the G×S. Data showed that a contribution of 25% of the overall G×S interaction was explained by selecting only five most plastic genotypes for the different traits analysed. Strong random changes were observed for the duration traits. The relative ecovalence analysis allows the identification of stable genotypes across environments and can be used as a tool in tree breeding.

Parole chiave: Populus Nigra, Bud Set, G × S Interaction, Phenotypic Plasticity

Citazione: Fabbrini F , Gaudet M , Harfouche A , Bastien C , Beritognolo I , Scarascia Mugnozza G , Sabatti M (2011). Phenotypic plasticity of bud set process in a P. nigra full-sib family . 8° Congresso Nazionale SISEF, Rende (CS), 04 – 07 Ott 2011, Contributo no. #c8.12.16