title: Effects of apical meristem mining on plant fitness, architecture, and flowering phenology in Cirsium altissimum (Asteraceae).
abstract: •
  
  
  OBJECTIVE
  Interactions that limit lifetime seed production have the potential to limit plant population sizes and drive adaptation through natural selection. Effects of insect herbivory to apical meristems (apical meristem mining) on lifetime seed production rarely have been quantified experimentally. We studied Cirsium altissimum (tall thistle), whose meristems are mined by Platyptilia carduidactyla (artichoke plume moth), to determine how apical damage affects plant maternal fitness and evaluate both direct and indirect mechanisms underlying these effects.•
  
  
  METHODS
  In restored prairie, apical mining was manipulated on tall thistles by applying insecticide, water, or no spray to apical meristems. We quantified effects on lifetime seed production, plant architecture, and flowering phenology. Seed germinability and seedling mass were evaluated in a greenhouse.•
  
  
  RESULTS
  Apical meristem miners decreased lifetime seed production of C. altissimum, but not seed quality. Higher mortality rates of damaged plants contributed to reduced seed production. Apical damage reduced plant height and increased the proportion of blooming flower heads in axial positions on branches. Apical damage delayed flowering and shortened flowering duration.•
  
  
  CONCLUSIONS
  Apical meristem mining reduced plant maternal fitness. The shift in the identity of blooming flower heads from terminal to axial positions contributed to this reduction because axial heads are less fecund. Shorter, meristem-mined plants may have been more susceptible to competition, and this susceptibility may explain their higher mortality rates. The kinds of changes in architecture and phenology that resulted from apical damage to C. altissimum have been shown to affect floral visitation in other plant species.
authors.affiliation: Department of Land Resources and Environmental Sciences, Montana State University, PO Box 173120, Bozeman, Montana, 59717-3120 USA.
authors.forename: Subodh
authors.initials: S
authors.lastname: Adhikari
authors.affiliation: Department of Biological Sciences, Wichita State University, 1845 Fairmount, Wichita, Kansas, 67260-0026 USA.
authors.forename: F Leland
authors.initials: FL
authors.lastname: Russell
mesh_terms: D000818:Animals; D031180:Cirsium / Q000254:growth & development / Q000502:physiology*; D017753:Ecosystem; D005298:Fertility; D035264:Flowers; D060434:Herbivory; D056626:Inflorescence; D018519:Meristem; D009036:Moths; D012098:Reproduction; D012639:Seeds; D013312:Stress, Physiological
keywords: Asteraceae; Cirsium altissimum; apical meristem mining; flowering phenology; insect herbivory; plant architecture; plant fitness; reproductive success