Open Access

ARTICLE

Study of the mitotic and meiotic chromosomes of sotol (Dasylirion cedrosanum Trel.)

by Hernández-Quintero JD, MH Reyes-Valdés, DV Mendoza-Rodríguez, M Gómez-Martínez, R Rodríguez-Herrera

1 Estudiante de Postgrado. Universidad Autónoma Agraria Antonio Narro, Departamento de Fitomejoramiento, Calzada Antonio Narro 1923, C.P. 25315 Saltillo, Coahuila, México.
2 Profesor e Investigador. Universidad Autónoma Agraria Antonio Narro, Departamento de Fitomejoramiento, Calzada Antonio Narro 1923, C.P. 25315 Saltillo, Coahuila, México.
3 Técnico Académico. Universidad Autónoma Agraria Antonio Narro, Departamento de Fitomejoramiento, Calzada Antonio Narro 1923, C.P. 25315 Saltillo, Coahuila, México.
4 Profesor e Investigador. Universidad Autónoma de Coahuila, Facultad de Ciencias Químicas, Boulevard Venustiano Carranza s/n, 25000 Saltillo, Coahuila, México.

* Corresponding Author:Address Correspondence to: M. Humberto Reyes-Valdés, e-mail:

Phyton-International Journal of Experimental Botany 2015, 84(1), 107-112. https://doi.org/10.32604/phyton.2015.84.107

Abstract

The genus Dasylirion is a group of plants typically present in the Chihuahuan Desert, perennial, with a dioecious sexual behavior and commonly called sotoles. This genus has been little studied from the biological point of view, and the bases of its reproductive response remain unknown. In this work we studied the chromosome number and meiotic response of Dasylirion cedrosanum in the county of Saltillo, Coahuila, located at the North East of Mexico. For the preparation of mitotic chromosomes, we used a technique based on enzymatic treatment with pectolyase and cellulase, as well as staining with acetocarmin dye. For the study of meiosis, male flower buds were collected, fixed and stained for analysis with the same dye. As a result, the gametic (n = x = 19) and somatic chromosome (2n = 38) numbers of D. cedrosanum are reported for the first time, being consistent with previous findings in other Dasylirion species, which points to a constant ploidy level across the genus. Variation was observed in the morphology and size of the somatic chromosomes, with types ranging from submetacentric to subtelocentric, and sizes oscillating in a range of 4.43 µm, with an average total length of 112.38 µm for the diploid chromosome complement. This shows that the chromosome complement of D. cedrosanom would belong to a 3B classification of Stebins, with a medium variation between chromosome lengths and low chromosome asymmetry. This variation indicates the feasibility of constructing a chromosome ideotype for this species. The meiotic chromosome pairing showed a chromosome behavior consistent with a disomic inheritance characteristic of a diploid species, with prevalence of ring and chain bivalents, typically without pairing abnormalities. Bivalent configurations in all cases were symmetrical.The normal and symmetrical meiotic pairing indicates a balanced production of gametes, and suggests the absence of heteromorphic sex determination.

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