Response of Mid-season Rice to Waterlogging at Filling Stage and Its Consideration in Design of Drainage Standard

YAN Jun; WU Qixia; ZHU Jianqiang

doi:10.13522/j.cnki.ggps.2017.05.011

Abstract：The impact of waterlogging at grain-fill stage on growth and yield of mid-season rice was experimentally studied.The impact of both waterlogging duration (from 3-9 days) and flooding depth (from 1/4 to 3/4 of plant height) at early grain-fill stage was examined.In the experiment,we measured the response of physiological traits and metabolism to the waterlogging.The results showed that the plant height,internode length,malonaldehyde (MDA) and peroxidase (POD) in the leaf blade sincreased with the waterlogging duration and flooding depth.Superoxide dismutase (SOD) in the leaf blade and SOD and POD in the roots change as follows:When waterlogging duration was 3 days they increased with flooding depth,while when the waterlogging duration is 6 and 9 days,they increased firstly and then decreased as the flooding depth increased.When waterlogging duration was the same,the MDA activity in the roots also increased first and then decreased as the flooding depth increased.Yield reduction was due to the decrease in panicle setting rate and grain quality.When the flooding depth was 1/4,2/4,3/4 and 4/4 of the plant height and the waterlogging duration was more than three days,the yield reduced by 10.73％,10.82％,22.23％,and 45.81％,respectively,in comparison with the control.Taking a reduction of 20％ in seed yield (80％ of relative yield) as a standard in designing drainage in paddy field,when the flooding depth was 1/4,1/2,3/4,and 4/4 of the plant height,the flooding water must be drained 9.9,5.0,3.3,and 2.5 days,respectively,after the watedogging happened,to ensure that the yield reduction does not exceed 20％.