Abstract Detail

Anatomy and Morphology

Dupin, Julia [1], Smith, Stacey [2].

Anatomy of reversal: evolution of fruit type in Datureae (Solanaceae).

Transitions between fleshy and dry fruits are common in many families of flowering plants, e.g. Gesneriaceae, Solanaceae and many monocot families. In Solanaceae, transitions between the different types of fleshy and dry fruits appear to be frequent, five shifts in each direction. Here we sample all principal fruit types in the Datureae tribe to trace the anatomical and developmental changes associated with the transition from a fleshy berry to a dry capsule. By focusing on Datureae, we can build on the previous work by Pabon-Mora and Litt (2011), which included the irregularly dehisced capsules of Datura inoxia. In addition to comparing the anatomical features of fleshy and dry fruits in the tribe, we explore the characters that could explain the different dehiscence mechanisms within species in Datura. Specifically, we test the hypothesis that regularly dehisced fruits are anatomically more organized, that is, that dehiscence zones are clearly marked, and pericarp cell organization is more uniform. Lastly, we place these results into phylogenetic context to determine if the transition between berries and regularly dehisced capsules was a stepwise process, given the number of traits likely required for a dry fruit.Our anatomical comparison of capsules and berries in Datureae and the analyses of character evolution show that the reversal seen in Datura fruits (from berry to capsule) results from a complex series of steps. The transition to a regularly dehisced capsule involves first the loss of endocarp collenchyma and gain of mesocarp sclerenchyma, followed by a change to large amphicribral bundles in the pericarp. The presence of large amphicribral vascular bundles is homoplasious in Datureae, but even so, we conclude that the organization of bundles is an important factor in dehiscence mechanism in capsules of Datura, and in differentiating regular and irregular dehiscence. While capsules and berries in Datureae are functionally different, we found overlapping anatomical characters between the two types of fruit, such as the presence of collenchyma in the mesocarp. Our results also demonstrate the relevance of phylogenetic context when discussing the evolution of characters. We found that the re-evolution of capsules in Datura fruits is due to the evolution of different characters when compared to other genera that produce capsules in Solanaceae.

1 - University of Colorado at Boulder, Department of Ecology and Evolutionary Biology, Campus Box 334, Boulder, Colorado, 80309, USA
2 - University Of Colorado-Boulder, School Of Biological Sciences, Campus Box 334, Boulder, CO, 80309-0334, USA

Keywords:
Datureae
Solanaceae
Fruit
capsules.

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 6:15 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: PAM008
Abstract ID:498
Candidate for Awards:Katherine Esau Award,Developmental and Structural Section best poster