亚种间杂交稻光合特性及物质积累与运转的研究

Photosynthetic Characteristics, Dry Matter Accumulation and Its Translocation in Intersubspecific Hybrid Rice

亚种间杂交稻穗大粒多,增产潜力大。同亚种内品种间杂交稻相比,亚种间杂交稻剑叶的气孔密度和气孔导度大,抽穗以后叶片的光合速率高。在抽穗期,亚种间杂种和亚种内杂种的干物质积累量相差很小,茎、叶和叶鞘中储存的可用性碳水化合物以及干重颖花比[干重(mg)/颖花(粒)],前者则小于后者。抽穗至成熟,亚种间杂种的干物质积累量和干重颖花比明显高于亚种内杂种,但前者的物质运转率、茎鞘物质的输出率和转换率均低于后者。对亚种间杂种物质运转率低的原因进行了讨论。

The yield-increasing potential of Intersubspecific hybrid rice (ISHR) was greater because of its large panicles, Compared with that of intervarietal hybrid rice (IVHR). ISHR had greater stomatal density and stomatal conductance, and higher photosynthetic rate from heading to maturity, The difference in dry matter accumulation was rather small between ISHR and IVHR before or at heading stage, but the former was lower or less than the latter in terms of the ratio of dry weight to spikelets [DW(mg)/spikelet] and the usable carbohydrate reserved in steams, leaves and sheaths at heading stage. The dry matter production and DW(mg)/ spikelet of ISHR, however, were more or higher than those of IVHS after heading. ISHR was lower than IVSR in the transfer ratio of assimilate, the export and transformation percentage of the matter in steams and sheaths. Reasons for the low translocation of the assimilate to grains of ISHR were discussed.