[目的]研究白及在不同郁闭度林下栽培的生长发育特性.[方法]在玉林市六万林场不同郁闭度(0～0.2、>0.2～0.4、>0.4～0.6、>0.6)的八角林林下开展桂及1号白及品种种植试验,分析其不同年龄的生长发育特征.[结果]郁闭度大于0.2时,随着郁闭度增加,白及叶片叶长增长,叶间距加大,但叶片宽度和地径(茎粗)变小;郁闭度大于0.4时,随着郁闭度增加,叶片SPAD值、氮素含量有所降低,而叶片含水量增加;白及生长4年后收获的假鳞茎鲜产量、干物率、干重产量不同郁闭度之间有一定差异,白及品质指标水分及多糖含量无显著差异.在郁闭度大于0.6时,不利于白及产量增加.[结论]品种桂及1号在今后的推广种植中,可在郁闭度小于0.6的林下种植.

为广西南部的福建柏(Fokienia hodginsii)容器育苗提供理论依据,首次进行福建柏容器育苗基质试验,采用黄心土、椰糠、泥炭土 3种基质,椰糠与泥炭土按1∶1配制成试验用的轻基质,设置5个处理,研究不同处理对苗木生长的影响,采用隶属函数法进行综合评价.结果表明:不同处理的苗高、地径差异极显著(P＜0.01),保存率差异显著(P＜0.05),其中T4处理(100％黄心土)的苗高、保存率生长表现为最好,地径生长表现仅次于T5处理,3项指标均与其他处理极显著性差异;苗木质量综合评价排序为T4＞T5＞T2＞T3＞T1.综上所述,广西福建柏的容器育苗基质以100％黄心土为佳.

为了探讨福建柏[Fokienia hodgirtsii(Dunn)A.Henry et Thomoas]在广西壮族自治区南部的生长及遗传变异规律,对种植于玉林市的50个家系生长性状进行测定和分析.结果表明,福建柏林木生长良好,4年生时平均树高为3.30 m,平均地径为8.11 cm,家系间生长性状存在显著或极显著差异,各性状家系遗传力为弱至中度,单株遗传力为弱度.初步筛选出10个优良家系,树高和地径的遗传增益平均值分别为0.254%和0.037%,选出7个优良单株,树高和地径的遗传增益平均值分别为0.420%和0.075%.

Objective]Effects of different fertilizers on Cryptomeria fortunei seedlings growth and nutrient uptake were studied, in order to provide reference for customizing fertilization measures for strong seedlings and plantation manage-ment.[Method]Randomized block experiment was applied to potted C. fortunei seedlings with four different treatments, namely no fertilizers (CK,treatment 1), sulfate granulated fertilizer (treatment 2), steam granulated fertilizer (treatment 3) and organic fertilizer(treatment 4). Seedling height, ground diameter, partial dry matters in upper ground and under-ground, nutrient content of nitrogen, phosphorus, potassium, hydrolytic available Phosphorus and available Potassium in the soil were measured after one year. [Result]Data of growth situation and nutrient contents of all treated C. fortunei seedlings varied greatly, but all were higher than those of CK(P<0.01) Among all the seedlings, those treated with treatment 2 showed highest height and biggest ground diameter, 24.4% and 40.7% higher than those of CK respectively. Seedlings contained highest content of plant dry matter, nitrogen, phosphorus and potassium under treatment 3, 216.0%, 119.4%,192.0%,198.8%higher than those of CK respectively. Available nutrient content of pot soil under treatment 4 was significantly higher than that under the other treatments (P<0.05). [Conclusion]Application of sulfate granulated fertilizer shortens the time before C. fortunei seedlings growing into qualified ones and being transplanted out of nursery. With treat-ment of steam granulated fertilizer, C. fortunei seedlings are more suitable for plantation in windy areas where seedlings are easily damaged by wind organic fertilizer can activate nitrogen, phosphorus and potassium in soil and increase contents of available nitrogen, available phosphorus and available potassium.

A hydroponic experiment was conducted to investigate the physiological mechanism of Lagerstroemia speciosa L.in re-sponse to salt stress.Six treatments with various salt contents (0,0 .2, 0.4, 0.6, 0.8 and 1.0%) were employed and ar-ranged by a completely randomized design with ten replications.Low contents (0.2 to 0.4%) of the stress had some roles in promoting to seedling growth, but high contents (0.6 to 1.0%) of the stress had inhibited seedling growth, while the effect of salt stress on the aerial parts was more than that on the roots.With the extension of stress time and the NaCl content ris-ing, the protective enzyme ( SOD, POD and CAT) activities were increased at the beginning and decreased afterwards, conductivity and MDA content were continuously increased.With the extension of stress time, the proline content increased at the low and medium concentrations, while increased and then decreased at the severe concentrations.With the increas-ing of NaCl, the total chlorophyll content increased and then decreased.Lagerstroemia speciosa L.had a certain ability to resist the salt stress.L agerstroemia speciosa L.improved the characteristic of resistance to salt stress by increasing the activ-ities of protective enzyme and optimizing the biomass allocation of organs.Under the severe contents, beyond the scope of the antioxidant system protection, salt stress on the plants also increased the damage, and the growth was severely affected.

以刨花润楠幼苗为试验材料,研究了在不同浓度硝酸铅处理下的地上和地下生长指标、保护酶活性、丙二醛、叶绿素含量以及电导率等各项生理指标.结果表明:低浓度(300 mg/L)的胁迫对刨花润楠幼苗生长有一定的促进作用,过高浓度的胁迫则抑制生长.刨花润楠幼苗叶片的总叶绿素含量以及保护酶SOD活性均随着胁迫浓度的升高呈先升后降的趋势.电导率、丙二醛含量随着胁迫浓度的升高呈现出先略降后上升的变化趋势.研究表明,刨花润楠幼苗对硝酸铅具有一定的抗性,适宜在一些硝酸铅污染地区进行推广栽植.

本研究目的为改良速生桉木材内裂及变形问题.方法:采用聚乙二醇(PEG)对速生桉湿材进行浸渍处理,通过检测增重率(WPG)、抗缩率(ASE)、变形及内裂,对速生桉木材在指接或拼接用途中表现出的尺寸稳定性差、变形等问题进行改良.结果:聚乙二醇处理速生桉木材随着浸渍时间的延长增重率和抗缩率随之提高;PEG对处理速生桉木材厚板的变形以及内裂情况有明显的改善作用,但对变形的改良效果并不十分凸显;对薄板的变形以及内裂情况有明显的改善作用,但对内裂的改良效果并不十分凸显.结论:聚乙二醇改良木材在初始一段时间内,浸渍时间是聚乙二醇渗入木材多少的重要因素,但过了某个时间节点后,聚乙二醇渗入到木材中的速率明显降低,因此不能盲目延长速生桉木材的浸渍时间.

以麻风树实生苗为试材，利用盆栽试验研究了氮、磷、钾配比施肥对麻风树幼苗生长和生理指标的影响。结果表明：与对照相比，不同氮、磷、钾配比施肥都显著提高了麻风树的生长和生理指标；经方差分析，氮肥对麻风树生长和生理影响最显著，磷、钾分别对不同的指标有不同程度的促进作用。模糊综合分析表明，在9种配比施肥处理中， N2 P3 K1（即N、P、K施入量分别为1．00、1．60、0．15 g／株）处理对麻风树苗期生长和生理指标促进作用最显著。