灌水模式对春小麦光合性能和干物质生产的影响

为探寻宁夏引黄灌区春小麦节水栽培的适宜灌水模式,比较分析了6个不同灌水处理(W1:二棱水+开花水;W2:二棱水;W3:拔节水;W4:二棱水+孕穗水;W5:二棱水+拔节水+孕穗水+开花水+灌浆水;W6:二棱水+拔节水+孕穗水+开花水)下春小麦光合性能、物质积累与转运、产量性状及水分利用的差异。结果表明,灌二棱水、孕穗水或开花水的W1、W4、W5、W6处理明显增加春小麦花后旗叶光合速率、蒸腾速率和气孔导度,灌二棱水和生育后期少灌水的W1、W2、W4处理明显增加花后旗叶胞间CO2浓度。灌水次数减少会显著增加旗叶SPAD值,并降低叶面积系数,其中以缺少二棱水的W3处理最为明显。灌有二棱水和孕穗水的W4处理明显降低抽穗至开花旗叶SPAD值,增加开花至灌浆旗叶SPAD值和抽穗至开花叶面积系数,灌开花水明显增加开花至灌浆旗叶面积。灌二棱水、拔节水、孕穗水、开花水明显促进了干物质积累,灌水次数增加明显增加了叶干物质积累量,并降低茎鞘干物质比例;缺少二棱水的W3处理最不利于叶、穗干物质积累,但提高了开花至成熟叶干物质比例;灌浆水对各器官干物质积累影响不明显。二棱期至开花期缺少灌水的W1、W3、W2处理促进了开花前贮藏同化物在花后向籽粒的转运。籽粒产量随灌水次数的增加而增加;缺少二棱水明显降低穗粒数、收获指数,但增加千粒重;增加灌水次数降低了灌水利用效率,且以灌二棱水影响最为明显。综上所述,缺少二棱水对春小麦产量影响最明显,孕穗水、开花水影响次之,灌浆水影响不明显。

Effect of Irrigation Modes on Photosynthesis Characteristics and Dry Matter Production in Spring Wheat

In order to screening suitable irrigation mode for water saving cultivation technique of spring wheat in Yellow River Irrigation region in Ningxia,photosynthesis characteristics,dry matter accumulation and distribution,grain yield and WUE of wheat were investigated under six irrigation treatments (W1: irrigation at two stages of double ridge and anthesis; W2: irrigation at double ridge stage; W3: irrigation at jointing stage; W4: irrigation at two stages of double ridge and booting; W5: irrigation at five stages of double ridge,jointing,booting,anthesis,and filling; W6: irrigation at four stages of double ridge,jointing,booting,and anthesis) through field experiment.The results showed that W1,W4,W5 and W6 treatments with irrigation at double ridge stage and booting stage or anthesis stage significantly increased photosynthetic rate,transpiration rate and stomatal conductance of spring wheat; and W1,W2,W4 treatments with irrigation at double ridge stage and less irrigation at late growth stage significantly increased intercellular CO₂ concentration.Decreasing irrigation times significantly increased chlorophyll content (SPAD) of flag leaves,decreased leaf area index (LAI),the most obvious was for W3 treatment with no irrigation at double ridge stage.W4 treatment with irrigation at booting stage significantly decreased SPAD of flag leaves during heading to anthesis stage,and significantly increased SPAD of flag leaves during anthesis to filling stage,significantly increased LAI from heading stage to anthesis,irrigation at anthesis significantly affecting flag leaf area of spring wheat from anthesis to filling stage.Irrigation at double ridge ,jointing,booting and anthesis stage significantly promoted dry matter accumulation of spring wheat,increasing irrigation times significantly promoted leaf dry matter accumulation,reduced the proportion of dry matter in stem and sheath.Lack of irrigation at double ridge stage significantly decreased dry matter accumulation of leaf and spike,increased the dry matter proportion of leaves during anthesis to mature stage.Irrigation at double ridge stage and booting stage significantly decreased the dry matter proportion of leaf from booting to anthesis of spring wheat,reduced dry matter accumulation of stem and sheath from anthesis to filling of spring wheat.Lacking irrigation at jointing and booting stage significantly increased dry matter accumulation of sheath and stem from heading to anthesis leaf,which affected dry matter accumulation of stage.Irrigation at filling stage did not affect the dry matter accumulation of stems and sheaths,leaves and spikes.Irrigation at booting,blossom and grain-filling stage significantly increased the dry matter proportion of spike from anthesis to mature stage.Irrigation at grain-filling stage did not affect dry matter accumulation of stems and sheaths,leaves and spikes.W1,W2,W4 treatments lacking irrigation from double ridge to anthesis stage were favorable for assimilating transportation amount before anthesis.Increasing irrigation times significantly increased grain yield,no irrigation at double ridge stage significantly decreased grain number per spike,significantly increased 1 000-grain weight,and significantly decreased harvest index.Increasing irrigation times significantly decreased water use efficiency and irrigation efficiency,the effect of irrigation at double ridge stage was the most obvious.Above all,the lack of irrigation at double ridge stage significantly affected grain production of spring wheat,followed with lack of irrigation at anthesis and booting stage,and the effect of irrigation at filling stage was not obvious.