刈割次数对苜蓿相关表型性状与饲草产量的影响

试验选取4份苜蓿材料,设4次刈割处理,观察测试表型性状及干物质的变化动态,并用DPS7.05数据处理系统对各性状指标与饲草产量的关系进行计算分析,以探讨刈割次数对苜蓿表型性状及饲草产量的影响,为高效优质生产提供依据。结果表明,刈割频度显著影响苜蓿越冬率(P<0.05),苜蓿株高、茎粗、茎叶比、分枝数等指标均随刈割次数增加呈明显降低趋势,其中WL525苜蓿首次刈割与其他3次刈割时的株高、茎粗均呈现显著性差异(P<0.05),茎叶比差异性不显著(P>0.05);而苜蓿饲草产量则随刈割次数增多而增加,与刈割1次的情况相比,WL525苜蓿刈割4次后产量增量最多,达1885kg/hm₂;4次刈割后试验材料饲草总产量从高到底的次序依次为WL525>WL903>赛迪>惊喜。全部材料中与饲草产量关联度最大的指标为株高和茎粗,其中株高与惊喜苜蓿饲草产量的关联系数最大,达0.3751;茎粗与WL525苜蓿、WL903苜蓿饲草产量的关联系数最大,分别为0.2854、0.1944。     

珠子参根茎发育特性及其切段繁殖的研究

[目的]研究珠子参根茎的发育规律,探索根茎繁殖的方法。[方法]通过对珠子参种子萌发过程和栽培植株生长期内根茎切片的观察,研究其根茎发生发育的规律;采用植物生长调节剂处理根茎切段,探索其根茎繁殖的方法。[结果]营养生长时根茎是单轴分枝的主杆,生殖生长时根茎成为合轴分枝式的侧枝。用50和100 mg/L的赤霉素(GA3)溶液、40和80 mg/L的6-苄胺腺嘌呤(6-BA)溶液均可使珠子参根茎的切段形成更新芽,但以40 mg/L 6-BA的处理为优,80 mg/L 6-BA的处理次之。[结论]该研究对珠子参规范化栽培措施的制订具有参考价值。     

不同处理方法对北高丛蓝莓扦插繁育的影响

扦插繁殖是近年来应用比较普遍的无性繁殖手段之一,可以有效的保留植物本身优良的遗传性状。分别对瑞卡、北陆两个北高丛蓝莓品种在小兴安岭林区进行扦插试验,结果表明:适宜的扦插基质对蓝莓扦插后的成活率和保存率起到重要作用,而使用不同激素配比及时间方案进行处理则会对蓝莓扦插生根质量产生不同影响。     

摩擦式自锁装夹切削锥形孔件的方法

摩擦式自锁装夹切削，是一种针对壁厚较薄，而孔径较大的锥形孔件能获得外观光洁，无接刀痕迹，内外径同轴度高，工件无变形无夹伤，生产效率高的制造方法。     

驱蚊草扦插繁殖的基质配方初探

试验以珍珠岩、蛭石、沙子和锯末为基本材料,按照不同比例混合,配成6种新的基质,并以纯沙为对照,比较不同基质配方对驱蚊草扦插繁殖的影响。实验结果表明,驱蚊草扦插易于成活;处理4(珍珠岩∶锯末=1∶1)综合表现较优,可作为驱蚊草扦插繁殖的基质,其次为处理3(珍珠岩∶蛭石∶草炭=2∶1∶2);驱蚊草扦插苗的根部对基质配方更为敏感,可作为筛选驱蚊草扦插基质的较优指标。     

盆栽龙胆的微体扦插繁殖研究

本试验采用5种不同扦插基质及4种不同规格的盆栽龙胆插穗进行微体扦插繁殖试验。结果表明，70％泥炭 30％珍珠岩较适宜龙胆扦插、生根，插穗长度以3节插穗为好。     

扶芳藤快速扩繁试验

分别采用扦插、播种和嫁接等扩繁方法,对红脉扶芳藤、宽瓣扶芳藤、紫红扶芳藤和金边扶芳藤等品种进行了快速扩繁试验,研究不同扶芳藤品种最适宜的繁殖方式和取材方法及各品种在不同繁殖方式中所需要的适宜条件和处理方法。试验结果得出:7月最适宜扦插,生根最快;红脉扶芳藤的生根能力强于宽瓣扶芳藤和紫红扶芳藤,1 a2、a生枝条强于当年枝,扦插30 d后可以进行移栽;种子经浓度为20 mg/kg的GA3处理最利于生长,根系数和株高均达到最大值。红脉扶芳藤嫁接在丝棉木上,成活率最高,达100%。     

杉木人工林不同采伐方式综合效益研究

采用层次分析法,对杉木人工林不同采伐方式的生态、社会、经济及综合效益进行分析,结果表明:经济效益方面,皆伐最高,70%择伐次之,50%择伐第三,30%择伐最小;生态效益方面,70%择伐最高,皆伐最小;社会效益方面,50%择伐最高,皆伐最小。综合效益以70%强度择伐最大,50%择伐其次,皆伐第三,30%择伐最小。建议杉木林主伐采用强度为70%择伐方式进行。     

Vegetative propagation of Colutea istria Mill. from leafy stem cuttings

This study investigates the optimal conditions for the vegetative propagation of the multipurpose leguminous shrub Colutea istria from leafy stem cuttings. The conditions examined included 1) the origin of the cutting (apical, medial or basal), 2) indole-3-butyric acid (IBA) treatment (0, 50, 200 or 400 mg/l), 3) the relative humidity of the propagation environment (high or low), 4) wounding base of cutting, and 5) the season in which the cutting was taken. The rooting ability of the cuttings was significantly influenced by all these factors. Winter cuttings obtained from the middle and base of the branch showed a greater rooting capacity than those harvested from the apical area, while autumn cuttings harvested from the middle and apical areas of the branch showed a greater rooting capacity than those harvested from the base. Winter cuttings showed the best rooting capacity than autumn cuttings. IBA treatment (200 mg/l), high humidity (98-100%), and wounding increased the rooting capacity of the cuttings. The sprout of new leaves was higher in basal cuttings, while IBA and wounding also significantly enhanced the root number of rooted cuttings. A method for vegetatively propagating C. istria plants is given.     

Difference in cutting age for highest profit by methods for calculating CO<Subscript>2</Subscript> emission trading and the price of CO<Subscript>2</Subscript>

 The amounts of CO₂ that are absorbed and emitted by forest in a model stand area were determined using two calculation methods, namely the flow approach and the stock approach for emission trading, to understand the relationships between the cutting age for the highest profit rate (CAHPR; optimum tree ages to be cut so as to maximize the profit) and (1) the prices of CO₂ and (2) the balance between CO₂ emission and absorption. The resultant CAHPR differed between these two CO₂ accounting methods, which give different tree ages for maximum log volume yield. A rise in CO₂ price caused the CAHPR to approach the tree age of maximum log volume in the flow approach method, and to deviate from the tree age of maximum log volume in the stock approach method. Even at the same CO₂ price, the CAHPR differed between the CO₂ accounting methods. At low CO₂ prices, the CAHPR did not affect situations where the difference of average profit is large by cutting age. On the other hand, the CAHPR was greatly affected at low CO₂ prices when the mean log volume growth changed with tree age. These trends were found to be universal. Received: September 18, 2001 / Accepted: October 25, 2002 Acknowledgments This study is one of the fifth science study subsidy projects of the Japan Forest Technology Association. Correspondence to:K. Sakata