The effects of film-mulching on the translocation and distribution in 14C-assimilates after anthesis in winter wheat (Triticum aestivum L.) on dryland

The effects of film-mulching on transportation and distribution of 14C-assimilates after anthesis of winter wheat on dryland were investigated using 14C-radiolabelling technique. The results showed that about 78% of 14C-assimilates was stored in the stem and sheath after 24 hours, 11% was transported into the kernels, and about 11% remained in leaves. At maturity, 14C-assimilates were almost entirely transported from the leaves, about 28% 14C was found in the stem and sheath, and about 70% was in the kernels. The 14C-assimilates in wheat with film-mulching were transported slower than that in the control. The results also suggested that under the film-mulching conditions, the leaves had higher chlorophyll contents, lower MDA contents, slower speed in the senescence and a stronger assimilability, while the wheat had much more dry matter and higher kernel yield. It was concluded that the reasons of the yield increase under the film-mulching were mainly on the faster growth during the early stage, the slower senescence in the later stage, and a stronger assimilation, leading to a great increase of the dry matter. However, this may not enhance the assimilate translocation and distribution to the kernels. (authors)