Emergence timing affects root-collar diameter and mortality in loblolly pine seedbeds

Eight half-sib families of loblolly pine (Pinus taeda L.) were sown in a nursery. Total germination, speed and uniformity of germination, root-collar diameters, mortality, and percent cull were recorded by family. Families which germinated quickest attained the greatest average diameters at the end of the growing season. Low variability in date of emergence led to correspondingly low variability in seedling diameter. When data for all families were combined, seedlings which emerged earliest experienced the lowest mortality, had the largest diameters, and produced the fewest culls.     

Prevalence and incidence of the root-inhabiting fungi, Fusarium, Cylindrocarpon and Pythium, on container-grown Douglas-fir and spruce seedlings in British Columbia

Surveys were made at the end of the 1990 and 1991 growing seasons for root-inhabiting fungi in the genera Fusarium, Cylindrocarpon and Pythium from the roots of one year-old container-grown Douglas-fir and spruce seedlings grown under greenhouse conditions. In the 1990 survey of four nurseries, it was found that 61–97% of both Douglas-fir and spruce roots were colonized with Fusarium, Cylindrocarpon or Pythium. There were significantly (p0.05) more Douglas-fir roots than spruce roots colonized by Fusarium at all nurseries, however, there were significantly (p0.05) more spruce roots than Douglas-fir roots colonized by Cylindrocarpon and Pythium. Root colonization of Douglas-fir and spruce by the three fungal genera during 1991 varied from 0–82% at three nurseries, however, only at a south coastal nursery was there significantly (p0.05) more spruce than Douglas-fir roots colonized by Cylindrocarpon. Significantly more seedlings were infected in 1990 than in 1991. In 1991, there were few significant differences between Douglas-fir and spruce, in the percentage of seedlings with colonized roots and in the percentage of growth medium colonized by the fungi. However, there were significant differences between nurseries.     

改进马尾松育苗方法的试验

对马尾松采用控制苗木密度、芽苗截根移栽和接种菌根菌等技术进行育苗试验，结果表明：苗木密度应控制在１５０株／ｍ２，芽苗截根以保留主根长度１／２为宜；采用厚环乳牛肝菌进行人工接种效果较好。     

广东林木种苗工程项目资金使用管理的问题与对策

概述了广东省林木种苗工程项目资金使用与管理现状,分析了其存在的主要问题,并提出解决问题的相关建议。     

水分胁迫对栓皮栎幼苗生理特性及生长的影响

通过盆栽实验，研究了在不同的水分条件下栓皮栎幼苗生理特性的变化和苗木生长量的变化。研究表明，在水分胁迫初期，随土壤含水量的降低，栓皮栎叶片的净光合速率、蒸腾速率下降，而水分利用效率提高。在水分胁迫末期，由于长期的干旱胁迫，水分条件最差的一组苗木已干枯死亡，土壤含水量从38．123％下降到20．323％时，净光合速率和蒸腾速率均下降，水分利用效率也下降。随着土壤含水量的降低，苗高、地径和生物量均有下降的趋势，其中生物量下降的幅度最大。     

Blight of conifer seedlings caused by Colletotrichum gloeosporioides

In a growth chamber experiment, 70-day-old seedlings of 10 conifer species were inoculated with Colletotrichum gloeosporioides conidia to determine the host range of the fungus. Based on the percentage of seedlings affected and the disease severity on individual seedlings, the order of most to least susceptibility was: western hemlock (WH), mountain hemlock, western larch, Sitka spruce, Engelmann spruce, Douglas-fir (coastal form, then interior form), white spruce and ponderosa pine; lodgepole pine and western red cedar remained unaffected. Inoculation of WH needles showed that within 24 h C. gloeosporioides conidia germinate and appressoria (penetration structures) form. A growth chamber study demonstrated that the pathogen can infect WH at needle wetness periods as short as 15 min; number of needles affected was higher at 0.5 h, but did not increase further even when wetness was extended up to 8 h. The results are discussed in relation to blight management of greenhouse-grown conifer seedlings.Portion of a Bachelor of Science (Honors) thesis, Department of Biology, University of Victoria, Victoria, British Columbia.     

林木组培工厂化育苗技术的研究

叙述了建立一间年产１００万株林木组培苗育苗工厂的情况。对实施林木工厂化育苗的技术路线，关键技术和几个生产工艺流程进行了论述，并对工厂的组成部分及设施，瓶苗大量移栽技术及组培苗苗圃管理等进行了较系统的研究。     

台湾杉引种造林试验初报

台湾杉在来舟林业试验场经6年的引种造林试验表明;1年生苗高16cm,造林4年后幼林平均高2.99m,胸径3.96cm;造林初期生长较缓慢,第4年明显加快;育苗与造林技术均容易掌握,具有重要的引种价值。     

思茅松苗木培育研究

文章分析研究了思茅松种子场圃发芽过程、种子千粒重与发芽率的关系、苗木生长量、菌根接种效果等，揭示了：①在思茅松的中心产区，种子场圃发芽率与千粒重呈线性正相关；②常温下，思茅松种子随贮藏时间的延长而发芽率降低；③伴生菌根菌接种是思茅松育苗的关键技术，苗木出土约３个月菌根接种良好是培育壮苗及苗木按时出圃的根本保证；④思茅松家系间苗期生长差异显著，为其遗传参数研究提供了早期的信息。     

河北省林木种苗发展现状、趋势与管理对策

总结了河北省林木种苗建设取得的成绩及存在的问题，根据林业和生态建设的新形势及河北省种苗发展现状，分析了林木种苗发展的趋势，提出了河北省林木种苗管理的总体思路和“坚持一个中心，抓好两件大事，建设三大体系，抓好四项工作”的管理对策。