<正>应用温室盆栽试验方法，采用完全随机试验设计，研究了1年生银杏（GinkgobilobaL。）实生苗在不同土壤水分条件下的生长和生物量分配。试验共设16个处理，即4个银杏半同胞家系（44号、11号、55号、32号）、4种水分水平（土壤含水量为土壤田间持水量的80%，60%，40%和20%），处理时问为100d。研究结果表明：（1）银杏4家系相对高生长、相对地径生长、生物量增量、单株叶面积、单株根系体积等均随着土壤水分含量的减少而减少；（2）55号和44号家系随着土壤水分含量的减少，根冠比逐渐增大，而32号和11号家系在前3种水分条件下随着土壤水分含量的减少，根冠比逐渐增大，但在W。水分条件下，根冠比均减少；（3）随着土壤水分含量的减少，银杏4家系根、茎和叶生物量增量均减少，但不同的家系减少程度不同，4个银杏家系在不同土壤水分条件下，根、茎和叶生物量增量均表现为根的最多，茎的次之，叶的最少；（4）不同家系银杏生物量增量分配到根系的比例随土壤水分含量的减少而增大，而分配到茎和叶中的比例则随着土壤水分含量的减少而减少。

The urea-formaldehyde(UF) adhesive is the most important adhesive in industry of wood-based panel. The present situation of UF adhesive for wood based panel is introduced. The existing problems in UF adhesive for wood-based panel were discussed. One of the most important problems is the pollution to environment and does harm to the health of formaldehyde released from production. Formaldehyde release from wood-based panel is influenced by a lot of factors. One of the most important aspects is the urea/formaldehyde mole ratio. The quantity of formaldehyde release from wood based panel is markedly influenced by type of UF adhesive. The methods to reduce formaldehyde emission of UF adhesive are introduced. The possible ways to improve the production level of UF adhesive are also put forward.