Progeny test analysis and population differentiation
of mesoamerican mahogany (Swietenia macrophylla)

Carlos  Navarro; Gustavo  Hernández

Progeny test analysis and population differentiation of mesoamerican mahogany (Swietenia macrophylla)

Autores

Carlos Navarro

Gustavo Hernández

Editor

Universidad de Costa Rica

Descripción

The performance of open-pollinatedsingle tree families of mahogany Swieteniamacrophylla from populations in Mesoamericawas evaluated in 3 trials established in northernCosta Rica. The trials at Upala and Lagartera(Los Chiles) contain families of Costa Ricanorigin, while the Laberinto (Los Chiles) trialcontains material from 6 Central Americancountries and Mexico. Data on root-collardiameter, total height, survival, and Hypsipylagrandella attack were collected. The analysisindicate significant family and populationdifferences for height and diameter, but H.grandella attacks were uniform over all sites.Heritabilities at 1.7 years for Upala were0.54±0.02, and 0.55±0.02 for diameter andheight, respectively; after this measurement thistrial was burned completely as a result of droughtin El Niño year, so further measurements couldnot be made. Lagartera at 0.7 years presentedheritabilities for diameter and height of0.55±0.008 and 0.57±0.008. Laberinto presentedheritabilities of 0.48±0.01 for diameter (2.9years), 0.6±0.01 for height, 0.1±0.002 for H.grandella attack; 0.07±0.002 for number ofshoots, and 0.18±0.003 for stem form 2.7 years after planting. Flooding in 1998 damaged theLagartera trial, which was also severely attackedby H. grandella. This resulted in very lowheritabilities, with large standard errors;therefore its genetic values in the firstmeasurement are considered unreliable. Theplantation recovered, and after 3 years geneticvalues were comparable with the other 2 trials.Isolated mother trees produced slow-growingfamilies in most cases, in comparison with theclustered ones or those in natural dense forests,suggesting inbreeding mechanisms.