不同品种冬小麦再生生长对刈割干扰的响应

Regrowth responses to cutting of different cultivars of winter wheat

为探究不同熟性冬小麦品种库源分配对刈割的响应,在温室控制条件下,选取陇东地区常用的中熟（‘宁麦5号’和‘陇育4号’）和晚熟（‘西峰27号’和‘陇育1号’）冬小麦品种,测定不同品种冬小麦不刈割（对照）以及分蘖期刈割（留茬2 cm）后再生生长早期叶面积指数,花期和成熟期的物质分配构成。研究结果表明：不同熟期冬小麦刈割再生后的叶面积指数、光合产物分配均有所不同。刈割后再生生长早期,4个品种叶面积指数较未刈割均显著下降;再生至花期中熟品种‘宁麦5号’和‘陇育4号’的叶面积指数仍显著降低27%和17%,晚熟品种‘西峰27号’略降低6%,‘陇育1号’则上升7%。中熟品种‘宁麦5号’和‘陇育4号’再生至花期地上生物量降低18%和11%,晚熟品种‘陇育1号’上升13%;各品种再生至花期地下生物量较未刈割均呈下降趋势,并且中熟品种的下降幅度小于晚熟品种,但晚熟品种在成熟期出现增加趋势,‘陇育1号’显著增加26%。再生至花期中熟品种各部分可溶性碳水化合物含量均降低,而晚熟品种‘陇育1号’各部分可溶性碳水化合物含量增加2%~12%。可见晚熟品种‘陇育1号’再生至花期可溶性碳水化合物含量及干物质向叶、穗分配增加,资源再分配、源库协调能力强,为后期籽粒产量形成奠定了良好的基础,较中熟品种更适于在分蘖期利用青饲草、成熟期收获籽粒的利用方式。

Source-sink distribution response to cutting of common mid-maturity（‘Ningmai5’ and ‘Longyu4’） and late-maturity（‘Xifeng27’ and ‘Longyu1’） winter wheat cultivars in Longdong region was analyzed in this study.Leaf area index（LAI） at early regrowth stage,dry matter distribution pattern at anthesis and maturity stages of cut wheat with 2 cm stubble and uncut（the control） wheat were analyzed.The results showed that LAI and photosynthetic products of different cut wheat cultivars were different.Compared with the uncut treatment,cut treatment significantly decreased LAI of ‘Ningmai5’ and ‘Lingyu4’ mid-maturity cultivars respectively by 27% and 17%,decreased LAI of ‘Xifeng27’ late-maturity cultivar by 6%,increased LAI of ‘Longyu1’ late-maturity cultivar by 7%.Aboveground biomass of cut ‘Ningmai5’ and ‘Lingyu4’ mid-maturity cultivars decreased respectively by 18% and 11% while that of cut ‘Longyu1’ late-maturity cultivar increased by 13% at anthesis stage over the uncut ones.Compared with the uncut treatment,the trend of the belowground biomass of the 4 cultivars under cut treatment pointed downwards with the decreasing trend of late-maturity cultivar higher than that of mid-maturity cultivar.However,belowground biomass of late maturity cultivar gradually increased at maturity stage with a significant increase of 26% in ‘Longyu1’ wheat cultivar.While carbohydrate content of all the parts of mid- and late-maturity cultivars decreased,that of ‘Longyu1’ late-maturity cultivar increased by 2%-12%.These suggested enhanced distribution of carbohydrate and dry matter to leaf and spike along with redistribution ability and source-sink coordination,which laid the basis for high grain output.Compared with other cultivars,‘Longyu1’ late-maturity cultivar was more suitable for forage utilization at tillering stage and harvestable grain at maturity.