title: Enhanced photosynthesis endows seedling growth vigour contributing to the competitive dominance of weedy rice over cultivated rice.
abstract: BACKGROUND
  Weedy rice, as one of the worst paddy field weeds worldwide, bears vigorous seedlings and dominantly competes with cultivated rice causing serious crop yield losses. To elucidate the causes of its stronger seedling vigour endowing its dominant competition with cultivated rice, comparative studies on seedling growth characteristics were conducted among six weedy rice biotypes and the two indica and japonica cultivars Shanyou-63 (SY-63) and Zhendao-8 (ZD-8), respectively, in the greenhouse.
  
  
  RESULTS
  Weedy rice emerged 2 to 3 days earlier, rapidly grew 1.3-1.7 cm taller daily, produced more secondary adventitious roots and greater aboveground fresh biomass than cultivated rice. Moreover, weedy rice exhibited greater photosynthetic pigment content, net photosynthetic rate, stomatal conductance, intercellular CO2concentration, transpiration rate, and chlorophyll fluorescence kinetic parameters. An enhanced overall photosynthetic activity in weedy rices was attributed to the combined action of a larger antenna, more active reaction centres and higher quantum yield for electron transfer beyond QA.
  
  
  CONCLUSIONS
  Enhanced photosynthesis of weedy rice at the seedling stage should be the main factor for leading to strong competitive dominance over cultivated rice. © 2016 Society of Chemical Industry.
authors: Weed Research Laboratory, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P.R. China.|College of Life Science and Technology, Henan Institute Science and Technology, Xinxiang, 453003, Henan, P.R. China.
authors: Lei
authors: L
authors: Dai
authors: Weed Research Laboratory, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P.R. China.
authors: Xiaoling
authors: X
authors: Song
authors: Weed Research Laboratory, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P.R. China.
authors: Baoye
authors: B
authors: He
authors: Weed Research Laboratory, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P.R. China.|Investigación y Desarrollo en Agricultura Tropical, S.A., Tambor, Alajuela, 4050, Costa Rica.
authors: Bernal E
authors: BE
authors: Valverde
authors: Weed Research Laboratory, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P.R. China.
authors: Sheng
authors: S
authors: Qiang
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D002734:Chlorophyll / Q000737:chemistry; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010788:Photosynthesis; D054046:Plant Stomata / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology / Q000528:radiation effects; D057685:Plant Weeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D002734:Chlorophyll; D002245:Carbon Dioxide
keywords: competition; photosynthesis; seedling growth characteristics; weedy rice