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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #316728
Title: Predawn respiration rates during flowering are highly predictive of yield response in Gossypium hirsutum when yield variability is water-induced

Author
item CHASTAIN, JACK - University Of Georgia
item CHASTAIN, DARYL - University Of Georgia
item MEEKS, CALVIN - University Of Georgia
item COLLINS, CALVIN - North Carolina State University
item Sorensen, Ronald - Ron

Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2015
Publication Date: 6/19/2015
Citation: Snidera, J.L., Chastain, D.R., Meeks, C.D., Collins, C.D., Sorensen, R.B. 2015. Predawn respiration rates during flowering are highly predictive of yield response in Gossypium hirsutum when yield variability is water-induced. Plant Physiology. 183:114-120. dx.doi.org/10.1016/jplph.2015.06.003.

Interpretive Summary: Carbon release by leaves during respiration under abiotic stress may have a major limitation to crop productivity; however, respiration rates of fully expanded leaves are positively associated with plant growth rates. Given the substantial sensitivity of plant growth to drought, it was hypothesized that predawn respiration rates would be 1) more sensitive to drought than photosynthetic processes and 2) highly predictive of water-induced yield variability in Gossypium hirsutum. Two studies (at Tifton and Camilla Georgia) addressed these hypotheses. At Tifton, drought was imposed beginning at the onset of flowering (first flower) and continuing for three weeks (peak bloom) followed by a recovery period, and predawn water potential , predawn respiration rates, net photosynthesis and maximum quantum yield of photosystem II (Fv/Fm) were measured throughout the study period. At Camilla, plants were exposed to five different irrigation regimes throughout the growing season, and average water potential and predawn respiration rates were determined between first flower and peak bloom for all treatments. For both sites, fiber yield was assessed at crop maturity. The relationships between predawn water potential, predawn respiration rates and yield were assessed via non-linear regression, and the interactive effects of predawn water potential and predawn respiration rates on fiber yield was assessed using response-surface analysis. It was concluded for field-grown Gossypium hirsutum that 1) Predawn respiration rate is exceptionally sensitive to progressive drought (more so than net photosynthesis or photosystem, 2) average Predawn respiration from first flower to peak bloom is highly predictive of water-induced yield variability, and 3) average predawn water potential during flowering alters yield response to predawn respiration.

Technical Abstract: Respiratory carbon evolution by leaves under abiotic stress is implicated as a major limitation to crop productivity; however, respiration rates of fully expanded leaves are positively associated with plant growth rates. Given the substantial sensitivity of plant growth to drought, it was hypothesized that predawn respiration rates (RPD) would be 1) more sensitive to drought than photosynthetic processes and 2) highly predictive of water-induced yield variability in Gossypium hirsutum. Two studies (at Tifton and Camilla Georgia) addressed these hypotheses. At Tifton, drought was imposed beginning at the onset of flowering (first flower) and continuing for three weeks (peak bloom) followed by a recovery period, and predawn water potential ('PD), RPD, net photosynthesis (AN) and maximum quantum yield of photosystem II (Fv/Fm) were measured throughout the study period. At Camilla, plants were exposed to five different irrigation regimes throughout the growing season, and average 'PD and RPD were determined between first flower and peak bloom for all treatments. For both sites, fiber yield was assessed at crop maturity. The relationships between 'PD, RPD and yield were assessed via non-linear regression, and the interactive effects of 'PD and RPD on fiber yield was assessed using response-surface analysis. It was concluded for field-grown G. hirsutum that 1) RPD is exceptionally sensitive to progressive drought (more so than AN or Fv/Fm), 2) average RPD from first flower to peak bloom is highly predictive of water-induced yield variability, and 3) average 'PD during flowering alters yield response to RPD.