叶面喷施ALA对几种苗木根系形态的影响

Effects of Foliar Spraying ALA on Root Morphology of Seedlings of Several Species

选择樟子松(Pinus sylvestrisvar.mongolica)、紫穗槐(Amorpha fruticosa)和元宝枫(Acertruncatum)2 a生容器苗,在其生长期分别喷施200和400 mg.L-15-氨基乙酰丙酸(ALA)3次,以喷清水为对照,在苗木生长停止、落叶前调查生长量并采集根系,利用WinRhizo根系分析系统,比较分析不同质量浓度ALA对各树种幼苗根系的长度、表面积和体积等形态特征的影响。结果表明:喷施ALA溶液,对3树种苗木的苗高、地径和地上生物量有一定的促进作用。苗木的根系与对照相比,喷施400 mg.L-1ALA使樟子松苗木根系的总长度、总表面积和总体积分别提高了170.91%、798.83%和740.60%,而喷施200 mg.L-1ALA仅使樟子松苗木根系总表面积显著提高146.83%;喷施200 mg.L-1ALA使紫穗槐苗木根系的总长度、总表面积较对照增加了93.99%和66.45%,而400 mg.L-1ALA处理对紫穗槐苗木根系生长的促进作用不显著;喷施200和400 mg.L-1ALA也可提高元宝枫苗木根系的总长度、总表面积和总体积,但与对照差异不显著;另外,喷施ALA能够显著提高樟子松和紫穗槐苗木细根(2 mm以下)长度和表面积,但对元宝枫细根长度和表面积的提高作用不显著。可见,喷施ALA可改善3个树种苗木的根系结构;对樟子松和紫穗槐苗木根系生长的促进作用明显,而对元宝枫的促进作用不明显。

Two-year-old vessel seedlings of Pinus sylvestris var rnongolica, Arnorpha fruticosa , Acer trun- catum were sprayed by different concentrations of 5-aminolevulinic acid （ALA） to probe its impact on the seedling height, stem diameter, leaf and stem biomass, root length and surface area, and seedlings vol- ume. The roots were collected before the seedling stop growing and leaf falling, water was used as the control the results were analyzed by root analysis system WinRhizo. The results showed that the spraying of ALA promoted the growth of seedlings, ground diameter, and above-ground biomass of the seedlings of 3 species. Compared with control, the root length, area and volume of P. sylvestris var. rnongolica in- creased by 170.91%,798.83% and 740.60% respectively with the spraging concentration of ALA of 400 mg·L-1and the root area increased by 146.83% with the concentration of 200 mg·L-1 ALA root length, area of A. fruticosa seedlings increased by 93.99% and 66.45% respectively with the concentration of 200 mg·L-1 and non promotion function was observed with concertation of 400 mg·L-1 ALA. There was no significant difference between the A. truncatum seedlings that were spraged by 400 mg·L-1 and 200 mg·L-1 ALA respec- tively. In additional, the length and area of fine roots （less than 2 ram long） of P. sylvestris var. mongolica and, A. truncatum seedlings increased significantly by spraying ALA, however, there was no significant functions to A. truncatum seedlings. It was concluded that the root structures of P. sylvestris var. mongolica, and A. fruti- cosa seedlings be changed by spraying ALA via the promotion of root growth of these two tree species.