Resumo

RODRIGUEZ-ROJAS, Teresa J. et al. Pollen viability, stigma receptivity and pollination type in five Echeveria species under greenhouse conditions. Rev. Mex. Cienc. Agríc [online]. 2015, vol.6, n.1, pp.111-123. ISSN 2007-0934.

Echeveria, is a representative genus from Crassulaceae to represent 97% of endemic genus; its plants have attractive morphological characteristics for ornamental horticulture. Knowledge of reproductive characteristics are useful for genetic improvement, necessary to be used in pollination and increase the chance of successful fertilization. The objective was to determine pollen viability, stigma receptivity and pollination type of five species of Echeveria, for breeding purposes. The work was done from 2011 to 2013, in Cuernavaca, Morelos. Five species E. agavoides, E. elegans, E. runyonii, E. pumila, E. perle were used. Pollen viability was determined by staining with carmine acetic acid. Stigma receptivity was assessed with the Osborn method; assessment was at 8:00, 10:00, 12:00, 14:00, 16:00, and 18:00 h. For pollination type four modes were performed: 1) self-pollination; 2) emasculating and cover flowers; 3) intra-specific cross-pollination; and 4) inter-specific cross-pollination; fruit set and seed viability was evaluated. E. agavoides had higher percentage of viable pollen (72.7%). Greater receptivity was from 12:00 to 14:00 hrs (94.6 to 98%). In the four modes of pollination 100% of fruit set was obtained; there was only viable seeds in fruits of intra-specific cross pollination (12.3%) and inter-specific cross pollination (11.3 to 12.3%). The pollination of the species studied were crossed E. perle and E. runyonii can not serve as females by not forming viable seeds.

Palavras-chave : Echeveria spp.; cross-pollination; generative reproduction; seed viability.