Abstract Detail

Development and Structure

Ray, Dustin [1], Miller, Elise [1], Arthur, Andrew [1], Savage, Jessica [1].

Spring floral phenology of temperate trees in relation to vascular cambium reactivation.

The phenological transition from winter dormancy to floral and leaf bud burst relies on the delivery of sugars and water to allow for growth of leaves and floral parts. The vascular tissues (xylem and phloem) are responsible for delivery of sugars and water, and as a result are crucial for the expansion of floral and leaf buds. The phloem could be especially important for delivering both water and sugar to developing buds because in many species sieve tubes differentiate and appear functional often weeks before the initiation of xylogenesis would allow movement of water to floral and leaf buds. While vascular cambium activity has been studied alongside leaf phenology, floral phenology is rarely reported despite its importance for plant fitness. To better understand the relationship between floral phenology and phloem reactivation, we collected stems from four co-occurring temperate species (Acer negundo, Cornus sericea, Alnus spp, Fraxinus pensylvanica) with differing spring floral and foliar phenologies from cambial dormancy in late February through xylogenesis in mid-June 2019. From transverse sections of ethanol-preserved stems, we measured the width of the cambial zone and the current season phloem and investigated their relationship to spring leaf and floral phenological events (ex. bud burst, anthesis, leaf out). Phloem thickness and cambial generally changed in opposition. In three of the four species, xylogenesis occurred after flowering, and in all four species, xylogenesis occurred prior to leaf out. Unraveling the dynamics of coordination between floral, foliar, and phloem phenology will allow for better predictions of flowering trees to changes in climate.

1 - University of Minnesota Duluth, Department of Biological Sciences, 1035 Kirby Drive 207 Swenson Science Building, Duluth, MN, 55812, USA

Keywords:
phenology
Phloem Architecture
Cambium
anatomy.

Presentation Type: Oral Paper
Session: DS3, Development and Structure III
Location: /
Date: Thursday, July 22nd, 2021
Time: 12:30 PM(EDT)
Number: DS3010
Abstract ID:581
Candidate for Awards:None