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Influence of Temperature on Leaf Dark Respiration of Diverse Tall Fescue Genotypes 1
Author(s) -
Volenec J. J.,
Nelson C. J.,
Sleper D. A.
Publication year - 1984
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/cropsci1984.0011183x002400050019x
Subject(s) - festuca arundinacea , biology , respiration , photosynthesis , horticulture , photoperiodism , point of delivery , yield (engineering) , zoology , environmental factor , botany , agronomy , poaceae , materials science , metallurgy
Reduction of dark respiration (R D ) of mature tissues could improve herbage yield of tall fescue ( Festuca arundinacea Schreb.), especially during summer. Our objectives were to 1) examine the response of R D of collared leaf blades to temperature in seven genotypes of tall fescue, and 2) examine the interrelationships between R D , concentrations of water‐soluble carbohydrate (WSC) and N Of leaf blades, and sward yield components. Seven randomly selected genotypes were vegetatively propagated into pots. In Exp. I, established plants were allowed to regrow in controlled‐ environment chambers at leaf blade temperatures of 20, 27, or 34°C, while in Exp. II regrowth of genotypes was at 20, 25, and 30°C. A 14‐h photoperiod with photosynthetic photon flux density of 650 and 665 μmol m −2 s −1 was provided in Exp. I and II, respectively. After 6 weeks of regrowth at the specified temperatures, R D of center‐sections of recently‐collared leaf blades was measured manometrically and CO 2 exchange rate (CER) was measured on similar leaves using an infrared gas analyzer. Within both experiments, R D at temperatures of 27°C or less were similar, averaging 10.8 and 6.8 μmol 0 2 kg −1 s −1 for the genotypes with the highest and lowest R D , respectively. At 30°C genotypes did not differ in R D but rates averaged 40% higher than those at 27°C or less. No plants survived at 34°C. The CER decreased as temperatures increased and was not related to R D or any other characteristic measured. At 27° C or less concentrations of WSC were lowest, while concentrations of N were highest in leaf blades of genotypes with high R D . As temperatures increased, concentrations of WSC decreased while N increased. Genotypes with high R D had significantly lower yield per tiller (YPT) and mass of WSC per stem base when compared with low‐R D plants. Genotypic variation for R D was apparent at temperatures between 20 and 27°C. Therefore, selection for altered R D would be more efficient at temperatures favorable for growth. Low N and high WSC concentrations of leaf blades may result from selection for low R D of collared leaf blades. Large stem bases with high concentration of WSC may also be selected indirectly with low R D , resulting in high YPT.