Abstract Detail

Anatomy and Morphology

MACK, JAIMIE-LEE K. [1], DAVIS, ARTHUR RALPH [2].

Studies of the growth pattern, anatomy, ultrastructure, and nectar composition of the petal spur of Centranthus ruber (Valerianaceae).

Certain angiosperm families contain species whose flowers form spurs – hollow, tubular outgrowths of the calyx or corolla that usually conceal nectar. In this way, a mutualism exists between plants with spurred flowers and their primary pollinators, commonly based on tongue length. However, spurs of only a few species have been examined for their patterns of growth. In Centranthus ruber, a species visited frequently by butterflies, each flower bears a short spur that initiates from a zone of cells at the abaxial base of the tubular corolla. After an inaugural period of cell division, cellular elongation (anisotropy) dominates almost exclusively to account for the spur’s final length (4.5 mm). Although the spur’s external surface is smooth - lacking trichomes and stomata - internally the spur possesses both secretory and non-secretory trichomes. The former are unicellular and secrete nectar along the abaxial surface of the spur’s entire length, whereas the non-secretory hairs may help ward off small, nectar-robbing insects. The unicellular secretory trichomes, plus the companion cells of the spur’s phloem supply, exhibit wall ingrowths but each represents a different type of transfer cell. Nectar secretion begins at anthesis and its carbohydrate composition (ca. 70% sucrose) remains constant as the flower ages.

1 - University of Saskatchewan, Biology, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada
2 - UNIVERSITY OF SASKATCHEWAN, Department Of Biology, 112 Science Place, SASKATOON, SK, S7N 5E2, Canada

Keywords:
Centranthus
cellular growth
nectar
spur
trichomes.

Presentation Type: Poster
Session: P, Anatomy and Morphology
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PAM007
Abstract ID:470
Candidate for Awards:None