Winter wheat (Triticum aestivum L. cv. Jingdong 8) was exposed to short-term high ozone treatment after anthesis and then was either well irrigated with soil water content (SWC) of 80-85 % (O 3 +W) or drought treated (SWC 35-40 %, O 3 +D). Short-term ozone exposure significantly decreased irradiance-saturated net photosynthetic rate (P N ) of winter wheat. Under good SWC, P N of the O 3 -treated plant was similar to that of control on 2 d after O 3 -exposure (6 DAA), but decreased significantly after 13 DAA, indicating that O 3 exposure accelerated leaf senescence. Meanwhile, green flag leaf area was reduced faster than that of control. As a result, grain yield of O 3 +W was significantly decreased. P N of O 3 +D was further notably decreased and green flag leaf area was reduced more than that in O 3 +W. Consequently, substantial yield loss of O 3 +D was observed compared to that of O 3 +W. Although P N was significantly positively correlated with stomatal conductance, it also had notable positive correlation with the maximum photochemical efficiency in the dark adapted leaves (F v /F m ), electron transport rate (ETR), photochemical quenching (q P ), as well as content of chlorophyll, suggesting that the depression of P N was mainly caused by non-stomatal limitation. Hence optimal soil water condition should be considered in order to reduce the yield loss caused by O 3 pollution.
In order to study the responses of winter wheat cultivars released in different years to short-term high O 3 exposure, an old cultivar ('Nongda 311', released in 1960s) and a modern one ('Yannong 19', released in 1990s) were treated with an O 3 exposure (145 ± 12 mm 3 m -3 , 4 h d -1 for 3 d) shortly after anthesis stage (> 50 % main stems blossomed). During the O 3 exposure, light-saturated photosynthetic rate (P N ) and stomatal conductance (g s ) of both cultivars decreased considerably. Elevated O 3 did not decrease dark-adapted maximum photochemical efficiency, but induced significant reduction in actual photochemical efficiency and thereby considerably increase in non-photochemical quenching. P N , g s of the modern cultivar 'Yannong 19' decreased more than the older one 'Nongda 311', indicating the former exhibited higher sensitivity to O 3 than the latter. After O 3 exposure, P N , g s and chlorophyll (Chl) content in flag leaf decreased more quickly than control, indicating induction of faster premature leaf senescence. As a result, the short-term O 3 exposure caused substantial yield loss, with larger reduction in 'Yannong 19' (-19.2 %) than in 'Nongda 311' (-8.4 %). Our results indicated that high O 3 exposure at grain filling stage would have greater negative impacts on the high yielding modern cultivar relative to the old one with lower yield.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.