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Post‐Harvest Seed Dormacy Effects on Kleingrass Germination Following Simulated Digestion by Cattle
Author(s) -
Ocumpaugh W. R.,
Tischler C. R.,
Valle L. S.
Publication year - 1995
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1995.0011183x003500010047x
Subject(s) - germination , dormancy , biology , digestion (alchemy) , panicum , seed dormancy , agronomy , horticulture , botany , chemistry , chromatography
Grass seed germinability declines linearly with increased exposure to in vivo and in vitro digestion, but the factors that regulate loss of seed germinability are unknown. One potential mechanism of seed survival during digestion is seed dormancy. A recently developed in vitro procedure to simulate grass seed passage through the digestive system of cattle ( Bos spp.) has permitted the evaluation of mechanisms controlling seed germinability following digestion. Our hypothesis was that ‘Selection 75’ kleingrass ( Panicum coloratura L.) seed with a high level of post‐harvest dormancy would withstand the negative effects of digestion better than TEM‐LD1 kleingrass seed with a low level of post‐harvest dormancy. Seed harvested in 1991 and 1992 was frozen to maintain dormancy status and subjected to 24, 48, and 72 h of in vitro digestion each year. Germinability was tested in half of the seed immediately following digestion, and half was stored at 24°C to allow for natural loss of dormancy. When germinated immediately following digestion, Selection 74 seed maintained most of its dormancy and germinated poorer than TEM‐LD1 kleingrass seed. However, after 6 to 8 mo of storage, digested seed of both genotypes exhibited similar linear declines in germination with increased digestion time. Seed of TEM‐LD1 digested for 48 or 72 h and then stored for 6 to 8 mo, germinated 15 to 25 percentage units poorer than similarly digested seed without storage. We concluded that post‐harvest seed dormancy of kleingrass is not an effective mechanism for maintaining viability of seeds when passed through the digestive system of cattle; however, such dormancy probably is a factor in maintaining seed viability after it is excreted.