title: [Effects of weak light stress on grain yield and photosynthetic traits of maize].
abstract: Through shading at 0-14 days before pollination (S1), 1-14 days after pollination (S2), and 15-28 days after (S3) pollination, this paper studied the effects of weak light stress on the grain yield and photosynthetic traits of maize cultivars FY3 and TY2. The results showed that all treatments of shading induced a decreased grain yield, among which, treatment S1 had the largest decrement, and FY3 was more sensitive to the shading. Weak light stress made the time of maximum grain-filling (Tmax) appeared later, grain-filling slowed down, and mass accumulation decreased. The earlier the weak light stress occurred, the later the Tmax appeared. During shading, the Chl (a + b) content, Chl a/b ratio, photosynthetic rate (Pn) as well as the photochemical efficiency (Fv/Fm) and actual quantum yield of PS II electron transport (phi(PS II)) in maize leaves decreased significantly, while the relative content of Chl b increased, and the intercellular CO2 concentration (Ci) and non-photochemical quenching (NPQ) increased markedly. After the shading ended, the Chl (a + b) content, Chi a/b ratio, Pn, Fv/Fm, phi (PS II), Ci, and NPQ restored gradually to the levels of non-shading, but the relative content of Chl b decreased, which suggested that non-stomatal limitation was part of the reason for the decreased Pn under weak light stress.
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian 271018, Shandong, China. jiashifang@126.com
authors.forename: Shi-fang
authors.initials: SF
authors.lastname: Jia
authors.forename: Shu-ting
authors.initials: ST
authors.lastname: Dong
authors.forename: Kong-jun
authors.initials: KJ
authors.lastname: Wang
authors.forename: Ji-wang
authors.initials: JW
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
mesh_terms: D018533:Biomass; D002523:Edible Grain / Q000254:growth & development* / Q000528:radiation effects; D010788:Photosynthesis / Q000502:physiology* / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects; D013472:Sunlight; D003313:Zea mays / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects
chemical_list: D045332:Photosystem II Protein Complex