| Abstract Detail
Physiology & Ecophysiology Melcher, Peter [1], Preston, Jill [2]. Understanding freezing and drought resistance mechanisms in Pooidae. Pooids constitute approximately 3,800 species of grasses, containing many of the world's most important crop, forage, and turf species, including barley, oats, rye, and tall fescue. Despite their ancestry in the tropics, pooids have diversified extensively throughout the temperate zones. This is probably due in part to their novel adaptation to an extended period of freezing/desiccation stress. The goal of this study was to determine the range of responses to freezing and drought of several grass species in this group. To achieve this, several different species of pooids were either subjected to drought treatments or cold acclimated and then subjected to freezing treatments. For the freezing experiments, leaf tissue samples were collected from cold-adapted plants and were then exposed to a suite of temperatures ranging from +5 to –30 oC using a controlled cooling environmental chamber. The temperature at which intercellular ice crystal formation occurred was measured by determining ice-nucleation temperature responses of tissue using fine-wire thermocouples interfaced to a datalogger. Cellular and tissue damage was also determined from ion-leakage and from chlorophyll fluorescence imaging of photosystem of samples exposed to the same cold temperature treatments. Plant responses to drought stress were assessed from pressure volume curve analysis of leaf samples and by determining the water stress that caused stomatal closure of plants exposed to varying drought conditions. Both soil and leaf water status were measured during drought treatments and stomatal closure was monitored using both a gas exchange system and determined from anatomical assessment from stomatal peels. Log in to add this item to your schedule
1 - Ithaca College, Biology, 953 Danby Road, Ithaca, NY, 14850, United States 2 - University Of Vermont, Plant Biology, 63 Carrigan Drive, 111 Jeffords Hall, Burlington, VT, 05405, United States
Keywords: Freezing drought fluorescence stomata.
Presentation Type: Poster Session: P, Physiology & Ecophysiology Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center Date: Monday, July 23rd, 2018 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: PPE003 Abstract ID:390 Candidate for Awards:None |