Efectos de progenies y arquitectura del roble pellín, Nothofagus obliqua (Mirb.) Blume

JAVIER PUNTIERI; JAVIER GROSFELD; MARINA STECCONI; CECILIA BRION; MARÍA MARTA AZPILICUETA; LEONARDO GALLO

Rosario, Argentina

Jornada; XXX Jornadas Argentinas de Botánica; 2005

Sociedad Argentina de Botánica

The architectural features of Nothofagus obliqua seedlings growing in a nursery were analysed and compared among seven progenies from the same region of Argentina (Quila-Quina). The length, number of nodes and basal diameter of annual shoots of the trunk and the position of branches and buds were recorded for at least 42 plants per progeny. Whereas first-year shoots had one extension unit (EU) for all plants, second-year shoots consisted of one or two EU. The probability of development of two EU was not affected by the progeny, but that of apex death was progeny dependent. Differences among progenies were detected in shoot size (length, number of nodes and diameter), the number of distal nodes withering after shoot extension and the node of origin of the relay branch after the death of a parent shoot’s apex. The likelihood of branch development from the distal nodes of a shoot was more affected by the withering and death of the distal portion of the shoot in some progenies than in others. The selection of a particular natural site for the collection of N. obliqua seeds for reproduction in nurseries should incorporate the seeding individual as a source of architectural variation among seedlings. By careful selection of seed-supplying trees within a N. obliqua population, morphological and architectural variability among seedlings may be reduced.