种基盘苗与营养钵苗根系生长和形态的差异

为了探明苗木培育方式与根系发育的关系,以侧柏、刺槐、白榆的幼苗为对象,研究种基盘苗与营养钵苗对幼苗根系形态的影响。结果表明：由于空气断根效应,种基盘苗抑制了侧柏和白榆主根的生长,促进了刺槐主根的生长,但种基盘能有效促进3个树种的主根沿着重力方向生长,使主根发达而且通直,侧根粗壮且分布比较均匀,营养钵苗的根系主根不明显,根系盘绕现象严重;侧柏和白榆2树种种基盘苗的一级侧根条数分别比其营养钵苗增加181.8%和128.6%,并能显著增加白榆种基盘苗的一级侧根直径;侧柏、刺槐和白榆种基盘苗的一级侧根均匀分布在1-2、2-3、3-4和4-5 cm 4个区间,而营养钵苗则集中分布在1-2和2-3 cm 2个区间;种基盘可以促进苗木一级侧根条数增加和均匀分布,对提高苗木吸收水肥能力和保土固土能力有着积极的作用。

Differences of root growth and morphology of seed base seedling and container seedling

In order to find out the relationship between the method of seedling culture and root development,we presented two methods for seedling breeding,i.e.Seed-base and container.Based on the seedlings of Platycladus orientalis,Robinia pseudoacacia and 3Ulmus pumila in the experiment,we found out that because of the effect of root air-cutting,seed-base check the taproot growth of P.orientalis and U.pumila,and promote that of R.pseudoacacia.Seed-base can boost taproot growth towards the gravity direction,and appear a performance of vertical upgrowth taproot and sturdy and evenly distributed lateral root. On the other hand,taproot is not evident and root swirlling is serious in container seedling.P.orientalis and U.pumila seed-base seedling has a 181.8% and 128.6% greater number of first-order lateral root respectively than that of container seedling,and the diameter of first-order lateral root of U.pumila is also stimulated by seed-base.For all three species,first-order lateral roots of seed-base seedling distribute evenly in the four parts of 12,2-3,3-4 and 4-5 cm,however,that of of container seedling distribute only in the parts of 1-2 and 2-3 cm.Seed-base stimulate the number of first-order lateral root and ensure its even distribution,which will play an important role in enhancing the root absorbency and the soil conservation function.