不同淹水时间对分蘖期中稻生育动态及产量的影响

通过盆栽定植试验,研究了中稻(徽两优6号、两优1128)在分蘖末期受不同淹水时间胁迫后生长发育和生理特性的动态变化,并同时考察了其产量结构。结果表明,淹水胁迫下,两个品种水稻生育期推迟,始穗到齐穗历时增加,且随淹水时间的增加而延长;淹水后短期内植株株高降低,但成熟前7 d时淹水2 d、4 d的处理株高反而略高于对照;植株绿叶数、绿叶面积、根长、根表面积、根体积、根系活力和相对叶绿素含量(SPAD值)均随淹水胁迫加重而显著减少(淹水2 d处理植株根系活力升高);但经过恢复生长,淹水胁迫后20 d,各淹水处理SPAD值已和对照非常接近,并且一直保持到成熟前7 d,其他各指标数值在轻度淹水胁迫(淹水2 d和4 d)下和对照接近而无显著差异,重度淹水胁迫(淹水6 d、8 d和12 d)下和对照差距缩小,成熟前7 d,由于淹水胁迫早衰严重而差距重新拉大;两个水稻品种减产幅度均随淹水时间的延长而加剧,淹水6 d处理的产量已经降至对照的50%左右,产量下降的原因是总粒数减少、空秕粒数增加和结实率降低等因素综合作用的结果。

Effects of Waterlogging Stress on Growth and Yield of Middle Season Rice at the Tillering Stage

A pot experiment was carried on the dynamic effects of waterlogging stress on growth and yield of middle season rice at the tillering stage. The results indicated that the growth period of two varieties were prolonged under the waterlogging stress. Compared to CK, the height of rice decreased in the early period, but the height of 2 d treatment and 4 d treatment increased in the mature period. The green leaves, green leaf area, root length, root surface area, root volume, root activity and SPAD significant reduced with the ag- gravate of waterlogging stress. After recovery growth, the SPAD and other characteristics of rice closed to the control, and then the gaps increased in maturity because of premature decay. The yield of two varieties decreased with the time of inundation, the yield of 6 d treatment had dropped to about 50% of the control. The reduction of yield was result from the decrease of total grains, the increase of empty grains and the decline of seed setting rate.