种植密度对小麦群体光能资源利用的调控效应

Effects of Planting Densities on Radiation Resource Utilization of the Wheat Colony

为提高小麦光能利用率和产量本试验于大田条件下,研究了种植密度对冬小麦品种石新828群体光能资源利用的调控效应。设置4个密度水平处理(210×104基本苗/hm2(D1)、270×104基本苗/hm2(D2)、330×104基本苗/hm2(D3)和390×104基本苗/hm2(D4))。试验结果表明,种植密度对小麦石新828群体光能利用具有显著的调控效应。D3处理的小麦群体合理,叶面积指数适宜,群体受光态势良好,且小麦群体的消光系数和生物量光能利用率均在生育后期表现出明显优势,最终使得小麦籽粒光能利用率及产量显著高于其他处理。D1和D2处理的群体透光率和净同化率在整个生育期均表现出明显优势,但由于小麦群体相对较小,农田漏光严重,干物质积累量显著低于其他处理;D4处理的群体叶面积指数和光合势在整个生育期均显著高于其他各处理,但由于群体相对较大,群体基部透光率较小,小麦群体的净同化率、消光系数和生物量光能利用率在生育后期表现出明显的劣势;最终均导致了小麦籽粒光能利用率和产量的降低。由此表明,在本试验条件下,适宜的种植密度使群体具有良好的受光结构和持久的光合同化能力,得到适宜的干物质积累量,协调营养物质向籽粒中转运,最终使小麦籽粒光能利用率高达0.572%。

A field experiment was conducted to evaluate radiation resource utilization of colony in different planting densities of a winter wheat cultivar Shixin828. It was studied under four different density levels（210 × 104 （D1） , 270 × 104（D2） ,330 × 104 （D3） and 390 × 104 （D4） basis seedlings per ha） . The results indicated that the dsnsity could remarkably influence the radiation utilization. The D3 treatment had the rational size of colony and Leaf area index and had apparent advantages in Light distribution,coefficient and radiation use efficiency of total biological yield at late growth period,with the grain yield and radiation use efficiency of grain yield of it being higher than that of the others significantly. The D1 and D2 treatments had apparent advantages in light transmission rate and net assimilation rate,but it had less Leaf area and dry matter accumulation as a result of less colony; Leaf area index and photosynthetic potential of the D4 treatment was higher than that of the others significantly,but it had apparent disadvantages in net assimilation rate,extinction coefficient and radiation use efficiency of total biological yield at late growth period with close microclimate as a result of great colony; both above reducing yield and radiation use efficiency of grain yield. The winter wheat had the best Light distribution,assimilative capability and suitable dry matter accumulation, with nutriment transporting to grain and its radiation use efficiency of grain yield being up to 0. 572% ,by rational ap-plication of planting densities.