核桃种子烂种原因及发芽条件的研究

对核桃种子的采集时间、调制方法、浸种和催芽技术等几个方面进行了系统研究，并进行了种子生理学的测定，其目的是探明核桃种子的烂种原因和发芽条件。结果表明，采种过早和堆沤过久都会引起种子霉烂，而种子吸水不足则是导致沙藏烂种和播种烂种的主要原因。同时也查明，种壳的机械约束是种子发芽慢的主要原因，较高的环境温度和充足的种子含水量是核桃种子发芽的适宜条件。采取适当晚采，合理调制和沙藏前适当浸种，播种前晒裂种壳，播种后提高地温等措施，可以减少烂种，加快出苗速度，提高出苗率。     

青海云杉种实害虫危害情况及综合治理调查分析

青海云杉的种实害虫有十几种，危害严重的有三种，即云杉球果小卷蛾、云杉蛀果斑螟和云杉梢斑螟，主要发生在甘肃祁连山林区。本文经过调查，根据青海云杉和种实害虫的生物学特性，提出加强青海云杉林的经营管理，尽量减少广谱性化学药剂的大面积使用；尽可能多的应用营林技术为主的、不杀伤天敌的防治措施，以达到青海云杉种实害虫综合治理的良性循环；并提出青海云杉种实害虫综合治理的策略、原则以及评价青海云杉种实害虫综合治理的步骤和方法。     

七叶树种子级别与种子活力及苗木品质的相关性研究

以七叶树种子为实验材料，并分级别绘制了种子的吸水曲线、测定了种子活力指数；同时，把种子按不同级别温室播种，分别测定其幼苗的苗高、地径、水势及电导率并作相关性分析。结果表明，种子级别与种子活力有相关性，中粒种子活力最强，小粒种子活力最弱；种子级别与苗木品质也有极显著的相关性，大粒种子萌发苗品质最好，小粒种子萌发苗品质最差。     

仙客来播种育苗试验

将仙客来种子用高锰酸钾质量分数1000×10 6液浸泡26h左右,进行种皮软化和消毒处理,然后播种在泥炭基质内,深度为(0 6±0 1)cm。在无光条件下保持温度(20±5)℃,湿度90%左右,在50～60d后即可发芽。发芽后应注意增加光照和施肥,也可以用稀释的肥料代替喷水,成苗率达89 9%。     

林木种苗质量检测的现状与对策

种苗检测是评定林木种苗质量的重要手段 ,根据《种子法》及新标准对种苗检测的要求 ,在分析种苗检测现状与存在问题的基础上 ,提出种苗检测的调整思路     

Petroleum flotation technique upgrades the germinability of <Emphasis Type="Italic">Casuarina equisetifolia</Emphasis> seed lots

The germination of Casuarina equisetifolia Forst seed lots is low (40–50%) even when freshly collected. This study aimed at upgrading the germination performance by removing non-germinable seeds using petroleum flotation technique. Seeds collected from 19 individual trees in seedling seed orchards in India were assessed using X-ray to determine the proportion of different seed lot fractions. The feasibility of petroleum ether as a separation medium was tested. Morphological characters of floating and sunken seeds were further studied using image analysis technique to examine their effects on the separation efficiency. The X-ray analysis revealed a large quantity of shrivelled, empty and insect-damaged seeds, altogether accounting 50%, which were the causes of low percentage germination of un-graded seed lots (48%). Petroleum flotation resulted in 90% germination in the sunken fraction and 4% in the floating fraction. The separation was distinct for most seed lots, except few seed lots that had relatively low germination in the sunken fractions and more than 10% germination in the floating fractions. As a whole, petroleum flotation appears to be a feasible technique to upgrade the germination of C. equisetifolia seed lots, and its efficacy is influenced by wing surface area, seed density and wing quotient of filled and empty seeds.     

Nursery soil cover influences germination of Thujopsis dolabrata var. hondai seeds

We examined the influence of nursery soil cover on germination of Thujopsis dolabrata var. hondai. Seeds were sown under seeding bed conditions: (1) nursery soil (andosol) without soil cover, (2) Kanuma pumice without soil cover, (3) nursery soil with nursery soil cover, and (4) nursery soil with sterilized sand cover. Germination percentages were compared between these conditions. The germination percentage (8.8%) at 10 weeks after sowing under condition 3 was significantly lower than under conditions 1, 2, and 4 (56.8%, 52.0%, and 47.2%, respectively). Of the nongerminated seeds under condition 3, 75.0% were decayed and several fungi were isolated from decayed seeds. An inoculation test of isolated fungi Cylindrocarpon tenue, Cylindrocarpon sp., Fusarium oxysporum, and Botrytis sp. to seeds showed that these fungi caused seed decay. Our results indicated that nursery soil cover may not be suitable for T. dolabrata var. hondai seeds sown in nursery soil because of seed decay by pathogens.     

Explaining variation in Brazil nut fruit production

Brazil nut is widely recognized as the cornerstone of the Amazonian extractive economy. Tight linkages between Brazil nut production, regional income, and intact mature forests have thrust this species into focus as a key component of Amazonian conservation and income generation strategies. Nonetheless, a comprehensive synthesis of factors explaining Brazil nut fruit production variation is lacking. We aimed to address this knowledge gap, asking: (1) What are the rates and annual variation of Bertholletia excelsa fruit production at individual and population levels? (2) What factors explain B. excelsa production variation, focusing on spatial and temporal variables, diameter at breast height (dbh), crown attributes, liana loads, and soil attributes? and (3) Does liana cutting affect fruit production?     

Germination of <Emphasis Type="Italic">Juniperus procera</Emphasis> seeds in response to stratification and smoke treatments,and detection of insect-damaged seeds with VIS + NIR spectroscopy

Seeds of Juniperus procera collected from five provenances across its geographic range in Ethiopia were subjected to cold-moist stratification at 5°C or 10°C for 6–12 weeks. The effect of aqueous smoke solution in overcoming the light requirement for germination, and the potential of visible (VIS) and near infrared reflectance (NIR) spectroscopy for sorting sound and insect-damaged seeds were also investigated. Highly significant differences in germination were detected among provenances (P < 0.0001) and stratification periods (P < 0.0001), but not between temperature regimes (P=0.111). Seeds from the south and southeast distribution ranges had higher percentage germination after 6 weeks of stratification than seeds collected from north, northwest and central ranges of distribution. The smoke treatment did not affect germination regardless of whether the seeds were exposed to light. Exposure to light increased germination capacity three fold. Sound and damaged seeds were distinguished with 90% accuracy using VIS + NIR spectroscopy. It can be concluded that dormancy in juniper seeds varies with provenances, and cold stratification for 6 weeks alleviates dormancy in some seed lots. Tentatively, smoke treatment seems ineffective in overcoming photo-dormancy in juniper seeds. VIS + NIR spectroscopy has demonstrated a great potential for sorting damaged seeds, thereby upgrading seed lot purity.     

提高杉木种子园种子产量及品质技术措施的研究

对湖南省东安县杉木无性系种子园施肥试验的结果表明：３、６、８月中旬每次每株各施尿素０．４ｋｇ、过磷酸钙０．３ｋｇ、氯化钾０．２ｋｇ为球花产量最高的施肥方案；施肥对当年的种子播种品质有影响，但不大；种子园大片母树不挂果的原因是土壤和树体中锰含量过高而树体中的硼元素缺乏，对此提出对土壤施石灰和对母树针叶喷Ｂ肥的改良措施；３—８月是杉木种子园施Ｎ、Ｐ．Ｋ肥最适宜时期；确定８月是杉木种子园母树营养诊断进行针叶分析的最佳采样时期，并制定出杉木种子园母树的针叶中全Ｎ含量为０．８％、全Ｐ含量为０．１２％、全Ｋ含量为０．７％是其临界值；针叶全Ｎ含量０．８—１．２％、全Ｋ含量０．７－０．９％是其最适浓度范围；中耕松土对种子园种子产量影响不明显。