Differential effect of whole-ear shading after heading on the physiology, biochemistry and yield index of stay-green and non-stay-green wheat genotypes.
Two winter wheat cultivars (the functional stay-green CN12 and non-stay-green CN19) were used to investigate the effects of ear-shading on grain yield and to elucidate the differential mechanisms of different cultivars. The photosynthetic parameters, chlorophyll fluorescence, antioxidant enzyme activities, and chlorophyll contents were measured 0, 15 and 30 days after heading (DAH) under both shaded and non-shaded conditions. The final grain-yield index was also measured. Shading had a smaller effect on the net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs), maximal photochemical efficiency of PSII (Fv/Fm) and coefficient of non-photochemical fluorescence quenching (qN) but a greater effect on both superoxide dismutase (SOD) and catalase (CAT) activities in CN12 than it did in CN19. Shading slightly altered the timeframe of leaf senescence in CN12 and may have accelerated leaf senescence in CN19. Moreover, shading had only a small effect on the weight of grains per spike (WGS) in CN12 compared with CN19, mainly resulting from the number of grains per spike (NGS) rather than the 1000-grain weight (SGW). In conclusion, the flag leaves of functional stay-green wheat could serve as potential "buffers" and/or "compensators" for ear photosynthesis, which is actively regulated by the antioxidant enzyme system and prevents yield loss. Thus, a functional stay-green genotype could be more tolerant to environmental stress than a non-stay-green genotype.
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.|Department of Biology and Chemistry, Chongqing Industry and Trade Polytechnic, Fuling District of Chongqing, China.
Qing
Q
Li
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Shengfu
S
Zhong
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Sifan
S
Sun
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Syeda Akash
SA
Fatima
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Min
M
Zhang
State Key Laboratory for the Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Wanquan
W
Chen
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Qianglan
Q
Huang
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.
Shengwen
S
Tang
Provincial Key Laboratory of Plant Breeding and Genetics, Sichuan Agricultural University, Chengdu, Sichuan, China.|State Key Laboratory for the Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Peigao
P
Luo
D002245:Carbon Dioxide / Q000378:metabolism; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D002523:Edible Grain / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005838:Genotype; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D054046:Plant Stomata / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
D002245:Carbon Dioxide; D002374:Catalase; D013482:Superoxide Dismutase