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Abstract Detail



Physiological Section

Goodale, Uromi Manage [1].

Water balance characteristics of terrestrial, epiphytic and saprophytic orchids as an indicator of habitat preference and basis for determining long term seed storage.

To face the uncertainities of climate change and also to manage the already occurring changes we need to have a greater research focus on understudied ecosystems and on key questions related to seed ecology. Orchids are at the front line of extinction, with more species under threat globally than in any other plant family. Orchid plants produced from seed are best for developing sustainable populations, and long-term cryopreservation in liquid nitrogen at is a viable option for seed storage. For long term storage to be successful, is important to understand how water balance and oil mobilization in seeds affect seed viability when seeds are thawed from subzero to higher temperatures. The water balance characteristics of seeds of selected five species each of terrestrial, epiphytic and saprophytic orchids from the different habitats were assessed and viability tests were compared for each species. Permeability of the seed coat was assessed using the activation energy for water loss (Ea). Using the Arrhenius equation, activation energy was calculated as the amount of energy that is needed by a molecule of water to cross the seed coat by considering the seed coat as an energy barrier. This was calculated using measurements of seed moisture content, seed water loss rates, seed coat permeability, and water absorption capacity. Our studt confirms that seeds of epiphytic orchids are more porous compared to those of terrestrial species and have higher activation energy and that saprophytic species have the least porocity and activation energy. Of the three seed viability assessment tests -- fliuorecine diacetate test, tetrazolium test, Evans blue test-- we found that , allthough generally the best viability test for assessing seeds is the fluorecine diacetate test, it is best to determine the appropritate viability test for each species.


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1 - Guangxi University, Plant Ecophysiology And Evolution Group, State Key Laboratory Of Conservation And Utilization Of Subtropical Agro-bioresources, College Of Forestry,, Daxuedonglu 100, Mengla, Nanning, Guangxi, 530005, China

Keywords:
orchid
Water relations
Seed storage
Habitat preference
Viability Testing.

Presentation Type: Oral Paper:Papers for Sections
Session: 53
Location: Salon 16/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 2:00 PM
Number: 53001
Abstract ID:1255
Candidate for Awards:None


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