Effects of the parasitism of Struthanthus flexicaulis (Mart.) Mart. (Loranthaceae) on the fitness of Mimosa calodendron Mart. (Fabaceae), an endemic shrub from rupestrian fields over ironstone outcrops, Minas Gerais State, Brazil

Fabiana Alves Mourão, Claudia Maria Jacobi, José Eugênio Côrtes Figueira, Eugênia Kelly Luciano Batista
2009 Acta Botânica Brasílica  
Parasitic plants (mistletoes) may alter the growth, reproduction and physiology of their hosts. Mimosa calodendron (Fabaceae) is a legume abundant in rupestrian fields on ironstone outcrops, frequently attacked by the hemiparasite Struthanthus flexicaulis (Loranthaceae). The objective of this study was to evaluate the consequences of parasitism by S. flexicaulis on the fitness of M. calodendron. The intensity of parasitism and mortality on hosts of different sizes was evaluated, and foliage
more » ... ed, and foliage cover, fruit and seed set in parasitized and non-parasitized individuals were compared. More than 65% of a population of 1820 individuals was attacked. Host density positively influenced parasitism. The mortality and number of attacked hosts increased with their crown diameter. Heavily parasitized individuals showed 75 to 95% reduction of leaf cover and fruit production of 25% of those non-parasitized. Although no statistical difference was detected between the number of seeds per fruit, seed weight was lower in attacked plants. Parasitism by S. flexicaulis on M. calodendron may alter its population structure and dynamics, by reducing survival and fecundity rates.
doi:10.1590/s0102-33062009000300023 fatcat:4szx7sfapndpfetw4x7qpwlrba