Respuesta germinativa de cuatro especies forestales nativas del macizo del Cajas

Abstract

Seeds are very useful in plant production for restoration and germplasm conservation purposes. The main goal of this study was to evaluate the germinative response of four native tree species (Hedyosmum luteynii, Myrcianthes rhopaloides, Oreocallis grandiflora, Weinmannia fagaroides) from the Cajas Massif. Seed morphology and seed physiology of these species were evaluated, through an imbibition test in order to define seed coat type for each species. Moreover, the type of endosperm, location of the embryos and the size of seeds and embryos were analyzed. Additionally, seed color were evaluated. In order to evaluate the germinative response of the species above-mentioned, the following thermic treatments were applied: 1) Warm stratification. 2) Cold stratification. 3) Immersion in gibberellic acid. 4) Acid scarification. The results showed that all species had permeable seed coat and also the seed color was a positive indicator for germination for H. luteynii and O. grandiflora. The endosperm and embryos for M. rhopaloides and O. grandiflora were classified as peripheral from a morphological point of view, H. luteynii classified as linear underdeveloped and W. fagaroides as linear fully developed. The stratification treatments did not affect the germination rate. Immersion in gibberellic acid caused higher germination rate and reduced the days until germination. The acid scarification produced a low germination in comparison with other treatments. The knowledge generated in this study on native tree species will have an application in reforestation and conservation programs.