Contribución al estudio polínico de especies ornamentales: "Bignoniaceae"

Abstract

The pollen morphology of twelve species of the genera Campsis, Catalpa, Doxontho„lacaranda, Pandorea, Podranea, Pyrostegia„Spathodea,Tecoma and Tecomaria, usually cultivated in the Mediterranean Region are studied by light and scanning electron microscopy. Pollen was acetolysed by the method of Erdtman (1960) modificated by Reitsma (1969) and mounted in glycerine jelly for light microscopy. For scanning electron microscopy the pollen were coated of gold evaporate. Centered in the tropics, particulary South America, this family is primarily entomophilous and their species has been shown as melliferous, but the numerous showy flowers of some species may shed pollen and to produce local concentracition in atmosphere and be caught by spore-trap. The twelve taxa examined can be divided into five well defined types: Campsis grandillora,C.radicans and Spat hodea campanulata have 3-colpate pollen; Doxantha unguis- cati, Pandorea jasminoides, P. pandorana, Podranea ricasoliana, and Tecomaria capensis have 3-colporoidate pollen; Jacaranda acutifolia have 3-colpate pollen; Pyrostegia ignea have 12-colpate pollen while Catalpa bignonioides and Tecoma stans have pollen grains agrupate in tetrades. However, the genera included in a same type can be separate on the basis of the sexine patterns.Se estudian con el microscopio óptico (MO) y con el microscopio electrónico de barrido (MEB) la morfología polínica de 12 especies de Bignoniaceae habitualmente cultivadas como ornamentales en la Región Mediterránea. Los taxones estudiados se pueden dividir en 5 clases en base a la morfología polínica que presentan: Campsis grandiflora • C. radicans y Spat hodea campanulata poseen granos de polen trizonocolporados; Doxantha unguis-cati, Pandorea jasminoides, P. pandorana, Podranea ricasoliana, yTecomaria capensis presentan granos de polen trizonocolporoidados; en Jacaranda acutifolia el polen es tricolpado y en Pyrostegia ignea 12-pantocolpado mientras que Catalpa hignonioides y Tecoma stans tienen los granos de polen agrupados en tétrades. No obstante, los géneros incluidos en una misma clase se han diferenciado, por tipos, en base a la ornamentación que presenta la superficie del grano de polen