Phenotyping and genotyping studies in native and cultivated forest tree species in Argentina

MARCUCCI POLTRI SN, SOLA G, ARANA V, BOZZI J, AZPILICUETA MM, PASTORINO M, SCHMID P, GAUCHAT ME, RODRIGUEZ G, BELABER E, ROTUNDO C, REDES J, PAHR N; FERNÁNDEZ ME, GYENGE J, MARTÍNEZ MEIER A, DALLA SALDA G, SERGENT AS, BAROTTO AJ, MONTEOLIVA S, ALARCÓN P, LÓPEZ LAUESTEIN D,COSACOV A, VEGA C , ; FORNÉS L, GRIGNOLA J, TRÁPANI A, LEDESMA T, TRANOWSKI C, CORTIZO S, CERRILLO TM, OBERSCHELP J, HARRAND L, ; SCHLICHTER T, FASSOLA H, HOPP HE, PANIEGO N, VERGA A, GALLO L, LÓPEZ J,MARCÓ M.

Talca

Conferencia; First Latin American Conference on Plant Phenogyping and Phenomics for plant breeding; 2015

Universidad de Talca

Phenotypic analyses of native and introduced tree species are carried out at the National Institute for Agricultural Technology (INTA) of Argentina since at least 30 years. Its national level Forest Program includes genetic analysis for breeding, conservation and restoration of natural ecosystems, aiming at increasing tree productivity, wood quality and more recently, resistance to different abiotic stresses.Molecular markers have been applied for breeding purposes mainly in Eucalyptus, Pinus, Populus and Salix species, and for diversity and phylogeographic analysis mostly in native Nothofagus spp., Austrocedrus chilensis, Salix humboltiana, Prosopis spp., Cedrela spp. and Araucaria spp. species. The genotyping systems used were: SNPs panel, SNP in candidate genes, DArT array, AFLP, SSR, cpSSR, RFLP-cpDNA. Large-scale phenotyping and genotyping for association analysis of field trial assays and native forest have been carried out for growth (in a conventional way: diameter at breast height-4 years old-, stem volume, total height), and physical and chemical properties of wood by Near Infrared reflectance (NIR): lignin content (Klason and total) and composition (Syringyl/Guaiacyl) and ethanolic extractives, and by conventional methods for determination of wood density stiffness and strength. Phenology and morphological traits, such as taxonomical traits of leaves and fruits, have been studied in native species. In addition, several ecophysiological traits related to drought stress resistance (e.g. maximum hydraulic conductance, xylem vulnerability to cavitation, wood capacitance, leaf osmotic adjustment, etc.) are being analysed in several forestry species (Pinus spp., Eucalyptus spp., Cedrela spp., Pseudotsuga menziesii, Austrocedrus chilensis and Prosopis alba) , trying to determine which traits are more important in terms of adaptability to climate change in species with different resistance mechanisms (avoidance vs tolerance). Relationships between these functional traits and easily measured traits, such as wood microdensity by X-ray methodology or NIR reflectance of wood or leaves, are being developed in order to have sound traits for large-scale phenotyping purposes. Other ecophysiological studies are exploring variation in traits related to resistance to multiple abiotic stresses (salinity, water-logging and drought) in Salix clones, resistance to low temperatures in Eucalyptus species, and high water use efficiency in Pinus spp. The identification of markers linked to genomic regions (genes and QTL) involved in the control of traits of interest were mainly focalized on two strategies that involved genome wide association analysis (GWAS) applied in E. grandis and E. globulus and genetic mapping in E. grandis. Information coming from these analyses was also considered in genomic selection studies in E. grandis.Phylogeography studies of different native forest species have being developed in order to characterize the genetic variation along their natural environmental distribution to detect high-priority populations for conservation and domestication purposes. In this regard, studies are available for: Nothofagus spp and Austrocedrus chilensis in Patagonia; Cedrela lilloi in Argentine Yungas Rainforest; Araucaria angustifolia in Argentine Northeast region; and Prosopis spp in Chaco, North Espinal and Patagonia regions.Marker assisted management of diversity was applied for six clonal seed orchards (CSO) of Pinus taeda L. to increase the efficiency and genetic stability in the commercial seeds through an appropriate design and management. Also diversity was evaluated in an introduced population of P. caribaea var hondurensis to be used as male in convenient hybridization with P. elliotti.Although conventional tree phenotyping techniques measure the most relevant traits, the addition of phenomics (large-scale phenotyping) combined with high throughput genotyping methodologies could greatly contribute to improve these previous studies and integrate the information provided by ecophysiological approaches in Argentine breeding and conservation forest programs.