Abstract

HERNANDEZ-VITAL, Carlos Rafael; ALVAREZ-MOCTEZUMA, José Guadalupe; ZAVALA-CHAVEZ, Fernando  and  ESPINOSA-ROBLES, Policarpo. Estudio cariológico de Quercus laurina Humb. & Bonpl.. Rev. Cien. For. Mex [online]. 2009, vol.34, n.105, pp.173-184. ISSN 1405-3586.

Oaks (Quercus spp., Fagaceae) are the most important broad-leaved trees of Mexico temperate regions, due to their abundance. However, they have rarely been studied from the karyological point of view. Little information about the genus Quercus exists, which is based upon American and European species. In these studies, it is reported that 12 is the chromosome basic number and 24 the somatic chromosome number. The objective of this research project was to make a karyological analysis of Q. laurina for taxonomy purposes. Root tips were isolated from young seedlings, preserved in 30g/L paradichlorobenzene and fixed on 6:1:1 (v:v:v) Carnoy's solution. Carmin-acetic was used to stain. The squash technique with acetic acid was used. Chromosome study was determined for mitotic cells during metaphase. Q. laurina karyological study show a diploid species, a basic chromosome number of x = 12, a haploid complement of 37.2 μm, a centromeric index of 40.83 μm, and a intrachromosomal asymmetry index of 0.28 and a karyotype of 18 metacentric and six submetacentric chromosomes. Q. laurina karyomorphology is similar to other Quercus species.

Keywords : Karyomorphology; karyotype; oak; Fagaceae; chromosome number; Quercus laurina.