Phenotypic variation of flowering and vegetative morphological traits along the distribution for the endemic species <em>Yucca capensis</em> (Agavaceae)

Abstract

Phenotypic variation across the geographic range of a species depends upon genetic differences within and between populations as well as environmental heterogeneity. Estimating the variation in morphological and reproductive traits and determining the influence of abiotic factors on the expression of phenotype is particularly important in endemic species as a means of inferring their response to different environmental scenarios. This study analyzes the interpopulation variation in oral and vegetative traits of Yucca capensis Lenz and their relation to altitude and precipitation. At 2 different sites total plant length, stem length, stem circumference, rosette length, rosette diameter, leaf length and leaf width were measured and the number of plants with inflorescences and fruits was recorded. The results showed higher coefficients of variation for plant length, stem length and rosette length and lower coefficients of variation for leaf length and width. All of the vegetative traits differed significantly between sites. It was found that 31 % and 12 % of the plants produced inflorescences and fruits respectively and inflorescence production differed between sites, presenting a positive relation with average annual precipitation. This study shows that there is large phenotypic variation in vegetative traits and that levels of rainfall have a clear influence on the production of reproductive structures throughout the geographic range of the endemic species Y. capensis.

Keywords

• Baja California Sur
• inflorescence
• fruits
• rainfall
• enviromental variation