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Adaptation of a white clover population to ozone stress
Author(s) -
HEAGLE ALLEN S.,
McLUGHLIN MICHAEL R.,
MILLER JOSEPH E.,
JOYNER RONALD L.,
SPRUILL SUSAN E.
Publication year - 1991
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1991.tb01008.x
Subject(s) - biology , trifolium repens , horticulture , population , stolon , clone (java method) , botany , dna , demography , genetics , sociology
summary White clover ( Trifolium repens L.) ‘Regal’ and tall fescue ( Festuca arundinacea Schreb.) ‘Kentucky 31’ were grown together in a field and exposed for two seasons in open‐top chambers to six ozone (O 3 ) regimes ranging from 0.59 to 1.95 times the ambient O 3 concentration. Plants that survived were propagated clonally and used in the present study to determine whether selection for resistance or sensitivity to O 3 had occurred. Relative foliar sensitivity of surviving clones to various short‐term O 3 , exposure regimes was determined with and without infection by several viruses. In tests of all surviving clones with viruses present, higher percentages of clones that survived two seasons at the high O 3 levels were resistant to short‐term exposure to O 3 , than were those that survived exposure to the low O 3 treatments. Only one of the 33 clones that survived exposure to charcoal‐filtered air (059 treatment) was O 3 ‐resistant while 19 of the 30 clones surviving the 1.95 treatment were O 3 ‐resistant. Conversely, eight clones that survived the 0.59 treatment were sensitive to O 3 while none of those that survived the l.95 treatment were sensitive. The results indicate that selection pressure in the presence of O 3 stress was for resistance to O 3 . Various combinations of five common viruses of clover were present among the surviving clones. Shoot‐rip meristem culture was used to free one O 3 ‐resistant and one O 3 ‐sensitive clone from at) viruses. The relative O 3 sensitivity of these two clones was not affected by viruses. Further testing is required to determine the relationships between relative foliar sensitivity to short‐term O 3 exposure and relative sensitivity to growth effects caused by long‐term exposure.