title: Morphological and physiological responses of different wheat genotypes to chilling stress: a cue to explain yield loss.
abstract: BACKGROUND
  The eco-physiological mechanism of wheat yield loss resulting from chilling stress is a fundamental scientific issue. However, previous studies have focused on hexaploid wheats, and few studies on the morphological and physiological plasticity of wheat plants. Six different wheat genotypes were tested under chilling stress to investigate the physio-morphological parameters as well as the loss of grain yield in growth chambers.
  
  
  RESULTS
  Chilling stress resulted in significant loss in grain yield in all genotypes. Under chilling stress, diploid wheats generated zero harvest, and tetraploid genotypes also suffered from a pronounced loss in grain yield, compared with the control group. In contrast, hexaploid genotypes acquired relatively high maintenance rate of grain yield among three species.
  
  
  CONCLUSIONS
  Diploid and tetraploid wheat genotypes maintained relatively large leaf area and high photosynthetic rates, but they were subjected to significant declines in vascular bundle number and productive tillers as a consequence of the inhibition by sink growth under chilling stress. The hexaploid wheats were found to have relatively low leaf area and photosynthetic rates. These genotypes also stored more soluble carbohydrates and exhibited stronger sink enhancement, ensuring the translocation and redistribution of assimilates. Our findings provided a new theoretical understanding of yield stabilization in the domestication process of wheat genotypes under chilling stress. © 2017 Her Majesty the Queen in Right of Canada. Journal of The Science of Food and Agriculture © 2017 Society of Chemical Industry.
authors.affiliation: Institute of Soil and Water Conservation, Northwest A & F University, Yangling, China.
authors.forename: Pu-Fang
authors.initials: PF
authors.lastname: Li
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada.
authors.forename: Bao-Luo
authors.initials: BL
authors.lastname: Ma
authors.affiliation: Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors.forename: You-Cai
authors.initials: YC
authors.lastname: Xiong
authors.affiliation: Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Zhang
mesh_terms: D002170:Canada; D002241:Carbohydrates / Q000737:chemistry; D003080:Cold Temperature; D005838:Genotype; D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000032:analysis; D011123:Polyploidy; D013312:Stress, Physiological; D014908:Triticum / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology
chemical_list: D002241:Carbohydrates; D010940:Plant Proteins
keywords: chilling stress; different wheat genotypes; grain yield; yield formation