[Caracterización y herencia del hábito de crecimiento colgante y esterilidad masculina en Vaccinium elliottii Chapman]

Abstract

Two plants of Vaccinium elliottii found in the forest in north Florida and named Chattahoochee and Torreya had a weeping growth habit characterized by a canopy with hanging branches. Chattahoochee was found to be male sterile. Morphological and reproductive studies were carried out to characterize the weeping growth habit, and attempts were made to develop a screening method that would identify the growth habit of seedlings at an early age in seedling populations thought to be segregating for normal and weeping growth habits. Also, progenies from crosses between male sterile Chattahoochee and male-fertile Vaccinium elliottii were studied to evaluate the inheritance of this trait. The weeping growth habit in Torreya was characterized as dichotomous, with some branches growing decumbent and others upright, but with the resulting average Propagation of Chattahoochee and Torreya by softwood cuttings showed a strong polarity. Callus and roots developed only from the proximal-cut ends. The orientation of the stems from which the cuttings were taken did not influence the subsequent growth habit of the plants produced from the cuttings. The screening methods that were tested to classify young seedlings for growth habit (light orientation, position of plants with respect to the pull of gravity, and growth of meristematic tips that were tied in a downward direction) did not clearly separate weeping and non weeping plants. The analysis of data from pollen amount and pollen staining is consisten with the hypothesis that male sterility was due to heterozygosity for a dominant male sterile gene in Chattahoochee