Comparison of Chlorophyll Fluorescence and Photosynthesis of Two Strawberry Cultivars in Response to Relative Humidity

• Published in: Weon'ye gwahag gi'sulji Vol. 38; no. 1; pp. 66 - 77
• Main Authors: Choi, Hyo Gil, Jeong, Ho Jeong
• Format: Journal Article
• Language: English
• Published: 한국원예학회HST 01.01.2020; 한국원예학회
• Subjects: 농학; stomatal conductance; transpiration rate; electron transfer; energy fluxes; root activity
• ISSN: 1226-8763; 2465-8588; 2465-8588; 1226-8763
• DOI: 10.7235/HORT.20200007

The aim of this study was to evaluate growth response of two greenhouse-grown strawberry cultivars grown under two different relative humidity (RH) regimes using photo-physiological measurements, such as photosynthetic rate and photosynthesis efficiency (with the initial chlorophyll fluorescence curve part of 0 ‑ 30millisec (OJIP) transients). The two different RH regimes (< 40% and > 60% RH) were maintained during daylight hours from November 20, 2018 to December 20, 2018. After 15 days of controlled humidity treatment, we found significant differences in photosynthetic rates, stomatal conductance, energy flux trapped by one active photosystem II reaction center (TRo/RC), and rate of electron transport flux of photosystem II reaction center (ETo/RC) values relative to cultivar type and RH. However, after 30 days of humidity treatment, the significant differences in these photosynthesis related parameters were responses related to RH treatment effects regardless of the cultivars. Both ‘Arihyang’ and ‘Keumsil’ cultivars grown under > 60% RH (during the day) showed higher root activity, reflecting multiple turnover of QA reductions (Ss), TRo/RC, and ETo/RC values than when grown under < 40% RH. In addition, relative variable chlorophyll fluorescence at 2millisec (Vj) and relative variable chlorophyll fluorescence at 30millisec (Vi) values were higher in the ‘Arihyang’ cultivar (regardless of RH) than in the ‘Keumsil’ cultivar. We conclude that maintaining high relative humidity inside greenhouses during the cold season (when RH is naturally low) will optimize strawberry fruit yield by enhancing root activity and photosynthetic rates. KCI Citation Count: 0