Low Allozymic Variation in the Bidens pilosa L. Complex (Asteraceae)

Abstract

Bidens alba, B. subalternans, and B. pilosa form a complex group based on their morphological similarities. Bidens pilosa L. and B. subalternans DC. are herbs with a wide distribution in agricultural and disturbed areas. Bidens alba (L.) DC. varies in size from herb to subshrub and has a coastal distribution. Enzyme electrophoresis was used to evaluate genetic diversity in 12 populations of Bidens. All but three loci (Lap-1, Est, and Got) were monomorphic. Est-1 and Got were polymorphic only in B. alba. Lap-1 was polymorphic only in B. pilosa and B. subalternans. The estimates of genetic variability were low for all three taxa and all of the populations studied. Genetic diversity varied from 0.01 to 0.03. Mean genetic identities were high among populations of each species (0.99 for B. alba and 1.00 for B. pilosa and B. subalternans) and among the three species (1.00). Bidens pilosa and B. subalternans could be considered a single species if the taxonomy of the group were based solely on isozyme data.

Molecular Basis of Resistance to ALS-Inhibitor Herbicides in Greater Beggarticks

“…Because only two ALS sequences were observed for region 3, two isoforms could have identical sequence in this region. The ALS isoforms of greater beggarticks showed homology with one ALS isoform from hairy beggarticks agreeing with Grombone-Guaratini et al (2005). According to the authors, greater beggarticks and hairy beggarticks could be considered a single species if the taxonomy group was based only on isozyme data.…”

Invasive congeners are unlikely to hybridize with native Hawaiian Bidens (Asteraceae)

“…The evolution of self‐compatibility in plants has long received attention and colonization of new areas is thought to lead to the evolution of selfing or for selection of self‐compatible variants (e.g., Baker, 1955; Stebbins, 1957; Ward et al, 2012; Petanidou et al, 2012). The evidence presented here and by Grombone‐Guaratini et al (2004, 2005) suggests that B. alba may have either latent genetic variation for self‐compatibility not expressed in its native range or the polymorphism exists at such low levels (Barrett and Schluter, 2008) it has not been previously detected (Ballard, 1986). Additionally, we found that the tetraploid species B. alba and the hexaploid species B. pilosa were cross‐compatible, but with low pollen fertility.…”

Resistance and differential susceptibility of Bidens pilosa and B. subalternans biotypes to ALS-inhibiting herbicides

“…Their similarity and overlapping of characters have resulted in imprecise taxonomic characterization, difficulty in establishing clear boundaries, and doubts about the material identification (Grombone-Guaratini et al, 2005a;2005b), even in resistance experiments. These weed species are difficult to control mainly because of their high levels of inbreeding and seed production, and long term survival of seeds on the soil (GromboneGuaratini et al, 2004).…”