Enhanced photosynthesis endows seedling growth vigour contributing to the competitive dominance of weedy rice over cultivated rice

作者：Lei Dai, Xiaoling Song, Baoye He, Bernal E. Valverde, Sheng Qiang · 发表于：Pest Management Science · 年份：2016 · DOI：10.1002/ps.4471 · 被引用次数：39 · 研究领域：Weed Control and Herbicide Applications、Rice Cultivation and Yield Improvement、Allelopathy and phytotoxic interactions

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 CO 2 concentration, 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 Q A . 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