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Water loss and viability in Zizania (Poaceae) seeds during short‐term desiccation
Author(s) -
Horne Francis R.,
Kahn Ari
Publication year - 2000
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2656748
Subject(s) - desiccation , germination , biology , dormancy , population , poaceae , seed dormancy , botany , recalcitrant seed , obligate , horticulture , agronomy , demography , sociology
How Texas wild rice, Zizania texana , became isolated in the San Marcos River of Central Texas, hundreds of kilometres from other wild rice populations is not known. Zizania seeds are intolerant of short‐term desiccation. Seeds desiccated at 14% relative humidity (RH) and 75% RH do not survive after only 5–6 d and 2–3 wk of drying. Water loss is rapid and reaches a maximum at the time of seed death due to drying. And although all Zizania seeds germinate well following a long, cold dormancy period, Z. texana seeds readily germinate in the isothermic water (22°C) of the San Marcos River and Springs without an obligate, cold dormant period. Within 30–60 d of collection, Z. texana seeds germinate in substantial numbers, unlike seeds of Z. palustris , which require a long, cold dormant period. The Texas population of Z. texana may represent a relict population of a once more widely dispersed wild rice population, since the San Marcos springs probably have never gone dry.