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Wheat Coleoptile and Root Growth and Seedling Survival after Dehydration and Rehydration
Author(s) -
Guedira M.,
Shroyer J. P.,
Kirkham M. B.,
Paulsen G. M.
Publication year - 1997
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1997.00021962008900050017x
Subject(s) - coleoptile , seedling , germination , dehydration , sowing , agronomy , biology , dry weight , horticulture , botany , biochemistry
Wheat ( Triticum aestivum L.) seed frequently is planted deeply in dry soil that supports germination but not emergence. Our objective was to ascertain the effect of dehydration on seedling survival and development, particularly the coleoptile and root, and their ability to resume growth after rehydration. Seeds of ‘Larned’, a tall, hard red winter wheat with a long coleoptile, were germinated for 1, 2, 3, 4, or 5 d and seedlings were dehydrated for 1, 2, 3, 4, or 5 d and then rehydrated. Seedling survival was greater than 75% after 1 to 3 d germination and all dehydration treatments, but declined from about 60% to zero after germination for 4 d and dehydration for 3 d or more. Dehydration reduced coleoptile lengths by 17 to 58% compared with the control. Seminal roots also were highly sensitive to dehydration, except at early stages, but were replaced quickly at all stages when seedlings were rehydrated. Changes in seed weight suggest that reserves were important for recovery of seedlings from dehydration. Increasing depth of planting and duration of germination successively reduced emergence of seedlings from seeds that were germinated for 1 to 4 d and then dehydrated for 2 d. The results demonstrated that emergence of wheat seedlings is increasingly impaired by dehydration as germination progresses, that the seedling stage when dehydration occurs is more important than the duration of the stress, and that coleoptile and root growth and seed reserves are involved in seedling responses to dehydration.