Abstract Detail

Biotic and abiotic stress

Mercer, Kristin [1], Perales, Hugo [2].

Flowering and fitness: plasticity and local adaptation in maize landraces in Chiapas, Mexico.

Plant populations evolve in response to environmental gradients resulting in differential adaptation. Mountainous regions, where elevation creates temperature, UV-B, and other clinal gradients, allow for study of plastic responses of wild and cultivated plants to environmental variation, as well as of local adaptation. In crop centers of diversity where landraces are common, understanding these phenomena facilitates basic understanding of evolutionary processes and provides insight for existing farming systems combatting climate change. We ask: (1) how does flowering phenology and fitness respond to environmental change and (2) to what degree do these patterns change with yearly variation? We collected maize populations along a transect in Chiapas, Mexico. Within 100m of each of three elevational levels (600m, 1550m, 2050m), we collected nine maize populations in three to four communities. In 2011 and 2012, these 27 populations were then reciprocally planted into randomized complete block design field experiments at three gardens, each at approximately one of the same three collection elevations. Landraces, especially from the highlands, had some minor difficulty flowering out of their elevation of origin, though this was exacerbated in the lowland and midland gardens in 2012. Flowering time was mostly influenced by garden with higher elevation (lower growing degree days) increasing time to flower; but the highland landraces also trended towards having the latest flowering, though less so as elevation increased. By contrast, anthesis-silking interval showed clear patterns of local adaptation (apart from short ASI commercial varieties) with the shortest values in the local types. Highland types had very low survival to reproduction under lowland conditions and midland types were also challenged there, while improved varieties had generally high survival to reproduction in all locations. For plants that did reproduce, we saw local adaptation and types were most differentiated under lowland conditions; the highland environment differentiated the types the least. Stress brought on by being out-of-place was reflected in our fitness metrics. Here, fitness appeared to be mechanistically linked to responses along a continuum from complete lack of flowering to not silking (retaining only male function) to delaying silking (elongating ASI). Thus, responses to stresses brought on by climate change will likely affect flowering and thereby affect important fitness traits. Future analysis will explore the direct relationship between these variables and consider how climate change may select on these flowering traits.

1 - Ohio State University, Horticulture and Crop Science
2 - El Colegio de la Frontera Sur, Agroecologia

Keywords:
none specified

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PBA013
Abstract ID:1116
Candidate for Awards:None