不同播期糜子抽穗后干物质积累及转运特性
Effect of Sowing Date on Dry Matter Accumulation and Transportation of Broomcorn Millet

为明确不同播期糜子抽穗后不同器官和顶三叶干物质积累及转运变化规律，确定陕北旱作地区糜子适宜播种期，以‘榆糜2号’为材料，自5月17日至7月15日每隔15 d设置1个播期，共设置5个播期（B1、B2、B3、B4、B5）。结果表明，不同播期糜子叶片、叶鞘、茎秆干物质积累均成单峰变化，即在抽穗后14 d干物质积累达到最大值，植株地上部分干物质总体呈上升趋势，积累量表现为B1>B2>B3>B4>B5。不同播期糜子植株籽粒干物质积累量在抽穗后均随生育进程的推进而增加，不同营养器官对籽粒贡献率表现为叶片>叶鞘>茎秆，且旗叶>倒二叶>倒三叶，说明叶片是糜子籽粒灌浆的重要源器官。总体表现为播期B3物质转运率最高，成熟期收获较高的籽粒产量。综合分析表明，糜子生产上应选择适宜的播种期种植，最大程度的提高营养器官物质转运率，是糜子增产的关键。
‘Yumi 2’ as experimental material,May 17 (B1), May 31 (B2), March 15 (B3) and June 30 (B4) and July 15 (B5) to clearly the variation of dry matter accumulation and transportation of different organs and three top leaves in broomcorn millet after heading stage, and to determine the suitable planting sowing at Shenmu. The results showed that the change of dry matter accumulation in leaves, leaf sheath and stem presented mono peak variation and reached maximum 14 d after heading. The aboveground dry matter accumulation presented a rising trend as B1> B2> B3> B4> B5. The grain yield per plant were increased with the growth period extended at different sowing date. The main source organ of grain-filling was the leaves and the contribution rate for grain was leaf>leaf sheath>stem, flag leaf>second leaf>third leaf. Sowing on March 15 (B3) showed the biggest transportation rate and the best yield gain. Thus, selecting the suitable sowing date is an important measurement for broomcorn mille production.