立体育苗模式下补光光源对烟苗根系生长的影响

为解决立体育苗模式中层间遮阴导致的烟苗生长发育不良问题,在层间设置了不同光源组合并研究其对烟苗根系生长的影响。结果表明:①层间遮阴通过补光能明显提高烟苗根系活力、吸收面积及物质积累量,在19.5~92.6μmol·m-2·s-1光强范围内,烟苗第3片真叶发生期后根系活力、吸收面积及物质积累量与光辐射强度呈正相关,光强愈大,根系生理指标增加幅度愈大。②蓝红LED灯头比例为2:1的处理,在第3片真叶发生期烟苗根系活力高于层间遮阴未采取补光措施的处理(CK2)73.5%,至第6片真叶发生期仍高于CK210.6%;根系总吸收面积在烟苗第2至第6片真叶发生期高于CK220.1%~36.2%,根系活跃吸收面积高于CK237.5%~56.2%;烟苗第4至第6片真叶发生期根鲜质量高于CK211.6%~22.7%,根干质量高于CK211.3%~20.1%。因此,在烟草立体育苗模式下采用的适宜补光措施为蓝红LED灯头比例为2:1的补充光源,功率16 W,光源距烟苗50 cm。 

Effects of Additional Light Irradiation on Growth of Tobacco Seedling Root System in a Multilayer Seedling Culturing System

In a multilayer seedling culturing system, the racks interrupt natural sunlight irradiation, it restrains the proper growth of tobacco seedlings, therefore different additional light source combinations were arranged between layers to study their influences on the growth of seedling root systems. The results showed that: 1) The activity, total absorption area, active absorption area and matter accumulation of seedling root systems were promoted by additional light irradiation; within the light radiation intensity of 19.5-92.6 μmol·m-2·s-1, these physiological indexes of root system positively correlated to light radiation intensity after the emergence of the third true leaf. 2) Appropriate ratio of blue/red LED emitters was 2:1, power16 W, the distance between light source and tobacco seedlings 50 cm; under such conditions, the activity of root system was 73.5% higher at the third true leaf emergence stage comparing with the treatment without light addition(CK2), which was still 10.6% higher at the sixth true leaf emergence stage; at the stage the second to the sixth true leaves emergence, the total absorption area of root system was 20.1%-36.2% higher, and the active absorption area was 37.5%-56.2%higher than CK2; at the stage the fourth to the sixth true leaves emergence, the fresh weight of roots was 11.6%-22.7% higher, and the dry weight was 11.3%-20.1% higher than CK2.