Abstract

SALAYA-DOMINGUEZ, José M.; LOPEZ-UPTON, Javier  and  VARGAS-HERNANDEZ, J. Jesús. Genetic and environment variation in two progeny tests of Pinus patula. Agrociencia [online]. 2012, vol.46, n.5, pp.519-534. ISSN 2521-9766.

Pinus patula Schiede ex Schltdl. et., Cham. is an endemic pine of México improved abroad because of its fast growth rate and should be evaluated to be reintroduced into the country. In this study the development of progenies with different breeding levels was compared in two trials in contrasting environments: Aquixtla, Puebla, at 2930 m (S1) and Acaxochitlán, Hidalgo, at 2260 m elevation (S2). Survival was evaluated at 6 years of age and at 5 and 6 years normal diameter (ND), total height (ALT), and stem volume (VOL) of 36 families improved in Colombia and South Africa (group M) and of 36 native families phenotypically selected (group S). At 6 years, survival was 72.7 % in S1 and 90 % in S2, with better growth in the latter site. There were significant differences (p≤ 0.05) between the two groups of families in all variables in both years. Progenies of the M group were higher in the volume of the trunk in S1 (4.3 vs. 3.6 dm³) but not in S2 (10.7 vs. 13.5 dm³). In S1, heritabilities ⁽h_i²) for growth traits ranged from 0.09 to 0.12 and in S2 from 0.26 to 0.35. Families of M Group had higher values of h_i² in S1 but in S2 values were similar. Genetic (r_g) and phenotypic (r_p) correlations between the growth variables for S1 and S2 ranged from 0.80 to 1.0 (≥ 0.80) at both ages. The genotypeX environment interaction (GX A) was high because the values of r_B in both ages were lower than 0.70 and 0.0 in some cases. The group of M families had lower GX A interaction in all variables evaluated.

Keywords : Pinus patula; G X A; progenies; genetic parameters; reintroduction.