丘陵黄壤区不同土层厚度下3个玉米品种花后水分利用效率比较

用水分试验池和人工干旱棚模拟0.4~1.0 m土层夏季干旱胁迫,研究不同基因型玉米花后水分利用特性。结果表明:花后植株伤流强度、叶片RW C、保水力与品种的抗旱性正相关,品种的抗旱性由强至弱的顺序为C 19>C 202>C 14,并且干旱处理的伤流强度和叶片RW C随土层增厚而增强;夏旱导致玉米灌浆持续期缩短2~4d,抽雄吐丝间隔期延长0~7 d;土层厚度和品种抗旱性均与籽粒产量和WUE正相关,土层深厚(1 m)夏旱胁迫处理有利于抗旱品种成单19提高籽粒产量和WUE。但以0.7 m土层的平均产量和WUE最高,其可作为坡耕地改造和利用的参考指标之一。

Effect of soil layer thickness and genotype on water use of maize after flowering

The experiment was conducted with pit growing and waterproof shed to evaluate the water use characteristics of maize with different genotypes after blooming period under the condition of 0.4~1.0 m soil depth and summer drought stress.The results showed that the intensity of plant wound flow,relative water capacity(RWC) of leaves and water conserving ability were positively related to the drought-resistance of varieties.The drought-resistance of varieties was C19>C202>C14,and the intensity of wound flow and RWC were added with the increase of soil layer.The milk filling period was shortened 2~4 d and the intervel between tasselling and silking was prolonged 0~7 d by the treatment of summer drought.Soil layer thickuess and drought-resistance of varieties were positively related to yield and water use efficiency(WUE).Summer drought was effective to increase yield and WUE of C19 with the treatment of 1.0 m soil layer,but the average yield and WUE of maize varieties were the highest with 0.7 m soil layer,which could be used as an index to reconstruct slope farmlands.