不同寄主桃小食心虫越冬幼虫的出土规律

室内试验表明,在适宜温湿度条件下,桃小食心虫越冬幼虫出土有一明显高峰,但不同寄主的幼虫出土高峰期不同,苹果上较早,枣和酸枣上较晚,且苹果桃小的出土始期也早于枣和酸枣桃小。同种寄主幼虫的出土高峰期几乎不受上年脱果时间的影响。干旱情况下的分期降水可造成幼虫出土的多峰现象,且降水量大时出土量大。在21～22℃下,越冬幼虫出土至成虫羽化的历期短于幼虫出土始期到盛期的时间。     

暮鼠越冬种群结构的年间变化

自1984年4月至1999年8月,我们沿铁路轨道检测了农田中暮鼠(Calomys venustus)的多度,研究了种群密度、越冬种群结构和繁殖期长度之间的关系,发现种群具有增长、高数量和下降年份。将动物按照同生群(种群内在相同时间内出生的一些个体)分开,利用2×2列联表卡方检验对不同性别的越冬种群结构与数量(高数量和种群下降)间的关联性进行了分析。就高密度与种群密度下降年份中的同生群组成而言,不同密度的年份显示种群结构有显著差异。在数量增长和高密度的年份里,在繁殖季节的起始期,前一年秋季出生的个体比同年夏季出生的个体在数量上要占优势,而在同生群数量下降年份则相反,特别是雌性。高密度年份具有繁殖期缩短的特征,而种群增长年份繁殖期延长。结果表明,这些变化不能只归结于繁殖期长或繁殖率引起密度变化。我们的结论是:解释C·venustus种群消长不能仅考虑动物同生群本身,需要考虑其社会和环境因子的作用。     

毛竹(Phyllostachys Pubescens)笋体生长及退败过程中生长调节物质的研究

毛竹笋体的生长极其迅速,在快速生长阶段,日平均生长量为35—50厘米,在高峰时可达1米(熊文愈,1962)。但出土的毛竹笋不是全部都能生长成竹,不成竹的笋称为退笋(退败),约占出笋的50％,除部分为虫害所致外,生理退笋占很大比例。本文从生理角度来研究毛竹笋体的生长和退败与内源生长调节物质的关系,为减少或克服生理退笋提供参考。     

寿竹笋的营养成分研究

为了促进寿竹资源的开发和利用,我们对不同出土高度寿竹笋的营养成分进行研究,探讨了寿竹笋的竹笋品质及其利用价值。寿竹笋的基本营养成分随出土高度不同具有一定的差异。在10 cm以下出土高度时,寿竹笋的维生素C、蛋白质、糖分等基本营养成分以及Ca、Fe、Mn等矿质元素的含量均为最高,其蛋白质的营养价值也最高。常量元素的含量依次是K>Ca>Mg>Na,微量元素含量依次是Zn>Fe>Mn>Cu,除Mn元素外其余矿质元素随笋龄的增加均未呈现明显的规律性变化。寿竹笋的含水率、VC含量、粗蛋白、总糖、灰分含量以及氨基酸总量、必需氨基酸和鲜味氨基酸的含量均高于相同出土高度的毛竹笋,其蛋白质的营养价值也远高于毛竹笋。结果表明,寿竹笋最佳采摘的出土高度为10cm以下;寿竹笋的营养物质丰富、笋味鲜美,具有极高的营养价值和保健功能。     

竹子箨叶形态性状的种间差异及其与竹笋食味品质指标的关系

竹笋是大众喜爱的森林蔬菜,其食味品质存在种间差异,且出土前后品质存在明显的变异.箨叶是竹笋的重要器官,居于箨鞘顶端,是竹笋出土时最先感光部位,是否与竹笋食味品质变异密切相关?目前尚不清楚.为此,以同一地点、立地条件和人工干扰措施一致的6个属22个竹种为对象,分析了不同竹种箨叶形态性状和竹笋食味品质指标,为揭示竹笋食味品...     

施肥对毛竹（Phyllostachys pubescens）竹笋生长的影响

 毛竹(Phyllostachys pubescens)为具有重要经济价值的高大乔木状竹种。本文通过完全随机化区组施肥试验,探讨了施肥量及施肥方式对毛竹竹笋生长的效应。结果表明：在毛竹林内施肥可使出笋数和活笋数提高3倍以上,但对竹笋(幼竹)的个体大小却几乎没有改良效果。竹笋的存活率基本上是恒定的,不随施肥量的改变而改变。当地下茎(竹鞭)穿越养分分布不均的环境时,竹笋能有选择地大量长于养分丰富的地段而避开养分贫乏的地段。另一方面,跨越于有利地段和不利地段的竹(笋)株间有明显的生理整合作用,而且这种生理整合在显著增加了长在不利地段的竹笋数(高收益)的同时,基本上没有减少长在有利地段的竹笋数(低耗费)。9m×9m的样方已足以观测到显著的施肥效果,这比传统的毛竹研究中使用的1亩的样方面积效率要高。在竹林培育方面,不均匀施肥如带状或点状施肥要比均匀施肥效率高。     

竹笋的转化酶及其与笋体生长速度的关系

本文报导了在竹笋中有转化酶的存在。在测定的各PH中,竹笋转化酶的活性在pH5.0时为最强。该酶的米氏常数为6.6×10~(-2)M。比较不同高度笋体各部分的转化酶活性时,发现在20厘米、80厘米、150厘米三种不同高度的笋体中,均以生长最快的中部的转化酶活性最大,但在300厘米高的笋体,则以上部的生长速度和酶活性最大。在同一节间内,转化酶的活性变化也与节间各部位的生长速度相一致;即以节间中部偏低的延长部位的酶活性及生长速度最大,而上部的成熟组织及下部的分生组织均较低。还原糖的含量与转化酶的活性及生长速度成相反关系。此外,在停止生长的退笋中发现转化酶的活性骤然降低。     

被竹海包围的村落

在以巨树王国著称的天目山脚下,有一群特殊的农民,他们不种粮食,终年侍弄竹子,以竹笋为业,源源不断地供给周边大城市所需的鲜笋和笋干。这个巨大的竹笋市场魔幻般地把这里变成了一片竹海,在给农民带来财富的同时也伴随着隐忧。[编者按]     

竹笋深加工及其功能活性研究进展

竹笋是一种高蛋白、低脂肪、富纤维的食品.本文综述了竹笋膳食纤维、活性多糖、含氮化合物等深加工产品的制备方法,比较了不同方法对竹笋深加工产品纯度、得率、功能活性等方面的影响;对竹笋改善肠功能、抗氧化、调节血脂血糖、消炎抗肿等方面的功能活性进行了论述;分析了目前竹笋深加工过程中存在的问题,对今后研究的方向、重点和趋势进行了展望.     

山东沂源猿人化石

本文记述了山东省沂源县骑子鞍山出土的一件人类头盖骨残片和七枚牙齿化石。它们的形态特征与北京猿人相似,在分类系统上应属直立人,与人类化石伴生的哺乳动物群的性质与周口店动物群相同,地质时代为中更新世。     

毛竹的无性系生长与立竹密度和叶龄结构的关系

毛竹为单轴型散生竹,属典型的无性系植物,原产我国亚热带地区。由于其个体高大、生长迅速、产量高、材质好、分布广,长期以来,一直是我国最为重要的经济竹种。本文应用无性系生长生理整合的理论,从种群统计学的角度,探讨了毛竹林立竹密度与叶龄结构对其无性系生长潜力的影响。结果表明：由于毛竹叶的生活期为两年,１龄新叶的光合能力比２龄老叶高,每样地的出笋数、活笋数与带１龄新叶的立竹数呈正相关,而与带２龄老叶的立竹数相关性不显著。另外,竹笋的死亡率是非密度制约的。本研究结果合理地解释了常见的毛竹林产量大小年交替变化的现象。     

Recruitment in Japanese sea bass,Lateolabrax japonicas (Cuvier, 1828): effects of timing on spawning and larval quality and quantity

This study aimed to elucidate the causes of variability in larval survival and juvenile abundance (recruitment) within and among cohorts of Japanese sea bass (JSB; Lateolabrax japonicus), a winter‐spawning temperate coastal marine fish. Larvae and settled individuals (settlers) belonging to four cohorts were collected from Tango Bay (the Sea of Japan coast) during eight sampling cruises in 2007 and 2008. Larvae were sampled in January and February each year using an ichthyoplankton net, and settlers were collected in February and March each year using a beam trawl. Age of individual larva and settlers was determined and growth history was back‐calculated from otolith microstructure, and the hatch date distribution was computed. Temperature, daily growth rate, size‐at‐age, hatch date, and density data of larvae and settlers allowed elucidating the effects of the timing of spawning and larval quantity and quality (growth rate and body size) on larval survival and recruitment within and among cohorts of JSB. Results showed that cohorts that hatched earlier in the season had higher quantity of larvae, experienced higher mean temperatures and survived better than cohorts hatched later. Recruitment variability among cohorts is determined largely by the initial quantity of larvae, as this explained >97% of the variability in recruitment among cohorts. Within cohorts, larger hatched larvae grew faster than their smaller conspecifics, and the bigger and faster growing larvae survived and settled. Results from this study suggest the following scenarios for recruitment of JSB: (i) earlier spawning in the season promotes larval survival since earlier cohorts are likely to encounter a better temperature and perhaps food conditions, and therefore recruit better than later cohorts; (ii) the initial quantity of larvae appears to be an important determinant of recruitment variability among cohorts; and (iii) the size‐ and growth‐related mechanisms operating during the larval phase appear to start at the time of the hatch.     

麻竹不同造林方式对当年新竹生长的影响

９９４～１９９６年在福建南靖县进行麻竹（ＤｅｎｄｒｏｃａｌａｍｕｓｌａｔｉｆｌｏｒｕｓＭｕｎｒｏ）扦插苗造林和移栽母竹造林试验,扦插苗造林发笋数比移栽母竹造林发笋数多０２５个／丛,新竹直径大１２１ｃｍ。扦插苗造林后,当年萌动新竹越多,新竹直径呈增大的趋势,随着新竹萌发的先后顺序,扦插苗造林的新竹平均直径也有相应增大的趋势。移栽母竹造林当年,新竹的大小受新竹数和母竹直径的影响显著,新竹直径与母竹直径呈正相关,新竹越多,新竹直径呈减小的趋势,其新竹平均直径随萌发先后也呈依次减小的趋势。     

糙花少穗竹生物学特性观察

糙花少穗竹是福建优良乡土竹种,笋材两用,其竹鞭、竹笋、幼竹生长节律与单轴散生竹毛竹相似。竹鞭垂直分布多数在土层20 cm范围,4~15 m长的鞭系占78.1%,发笋期较集中在3月中下旬,单个笋重为盛期笋> 初期笋> 末期笋。从笋出土到幼竹高生长停止,可分为初期、上升期、盛期和末期。但竹鞭垂直分布比毛竹浅,出笋期比毛竹早,且出笋没有明显的大小年,具有较高的开发利用价值。在自然分布区可根据其生物学特性、竹鞭生长与发笋成竹规律采取相应技术措施,垦复改造荒芜野生竹林,2~3年即可郁闭成林。     

Dynamics of cohorts of cladodes and related effects on reproduction in the shrub Retama sphaerocarpa in semi-arid south-eastern Spain

Changes in the size and age structure of the canopy of the leguminous shrub Retama sphaerocarpa in semi-arid south-eastern Spain were investigated by monitoring growth and survivorship of cladodes (photosynthetic stems) on marked shoots over a period of 26 months. Three basic morphological types of cladodes – long shoots, short shoots, and secondary short shoots – were distinguished.The canopy of the shrubs contained three annual cohorts of cladodes in spring and summer. The number and size of shoots produced each year was highly variable and was apparently related to the amount of rainfall during the preceding cool season. The spring cohort of 1994 produced only 37% of cladodes compared with 1993. Two cohorts of shoots were actually initiated in spring and late summer of each year, but the second cohort produced only 2–12% of the number of cladodes compared with the spring cohort. The proportions of the different cohorts in the canopy changed rapidly from April to August, but only slowly during the remainder of the year when only two annual cohorts remained after extensive litterfall in late summer. This late summer litterfall caused a substantial reduction in green canopy area (40–50%) which was achieved mainly be shedding of one year old cladodes. The life expectancy of cladodes decreased with increasing order of their morphological type from 850 ± 25 days in long shoots to 563 ± 4 days and 546 ± 9 days in short shoots and second order short shoots, respectively.Flowering and fruiting took place from May to July, almost exclusively on one year old cladodes, and coincided with the maximum development of the canopy. Flowering intensity was high in 1994, when individual shoots supported a mean number of approximately 150 flowers. Shoots produced an average of 12.6 ± 0.6 and 5.3 ± 1.0 fruits per shoot in 1993 and 1994, respectively. Most of the annual fruit crop (80–90%) was shed during litterfall in late summer. A proportion of 10–20% was retained in the canopy for up to 12 months, however, with some fruits persisting for more than 22 months.     

Differences in Shoot Size and Allometry between Two Evergreen Broad-Leaved Shrubs, Aucuba japonica Varieties in Two Contrasting Snowfall Habitats

Aucuba japonica , an evergreen broad-leaved shrub. Aucuba Japonica var. borealis is widely distributed in heavy snowfall areas in Japan and is covered, shaded and physically pressured by snow for more than four months of the year. On the other hand, var. japonica is widely distributed in light snowfall areas. The sizes of new shoots and leaves were significantly different between the two varieties with different critical shoot sizes for flowering. The average new shoot dry mass of var. borealis was about one third of that of var. japonica. Despite the differences in growing conditions and shoot size, no significant differences were observed in the allometry of their shoot organs between the two varieties. Large new shoots had thicker and longer stems per biomass than small shoots because of their larger pith volume. The large shoots showed higher efficiency of stem growth per invested biomass and had a higher rate of annual height increase than small shoots. When the size of new shoot rapidly increased from year to year, i.e. the plants are growing well, initiation of flowering was postponed and vegetative growth continued. Small new shoots were tolerant of low productivity conditions but traded vertical growth for an increase in matter allocation to leaves. Received 8 July 1999/ Accepted in revised form 1 September 2000     

Shoot population dynamics of persisting clones of<Emphasis Type="Italic"> Miscanthus sinensis</Emphasis> in the warm-temperate region of Japan

The population dynamics of annual shoots in four clonal patches of Miscanthus sinensis was surveyed in terms of clone persistence. Over a study period of 3 years, a stable net shoot number was attained through a balanced replacement of old shoots by tillering 2–3 times a year. The birth rate was significantly correlated with the average monthly temperature. This suggests that a warm climate advances the date of tillerings, and shoots become taller as they emerge earlier. Five cohorts were identified, corresponding to shoots that were born in spring, early summer, summer, autumn and early winter. The autumn cohorts were more numerous and had a greater longevity than the other cohorts; they were thus were best suited for overwintering and, consequently, maintaining the population from one generation to the next. The shoots of earlier cohorts grew too tall to survive the cold of winter, which might cause freezing injury, while later cohorts shoots excelled in overwintering because of their shortness. However, if the delayed shoots are very short, they will also have difficulty in surviving the early season of growth. Therefore, M. sinensis shoots have an optimum size for survival.     

中国亚热高大竹类植物毛竹竹笋克隆生长的密度调节（英文）

 对许多多年生克隆植物来说,大量的研究表明：当光是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小、死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明：竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加而增加。更确切地说,竹笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶(1龄叶)的成竹立竹度的增加而增加,而与带老叶(2龄叶)的成竹立竹度相关性不显著。并且竹笋的死亡率是非密度制约的。这可能是由于对毛竹来说,其立地总是比较开敞,而且,其竹笋的生长在很大程度上是不直接需光的。     

Winter peridermal conductance of apple trees: lammas shoots and spring shoots compared

Lammas shoots are flushes formed by some woody species later in the growing season. Having less time to develop, tissue formation is suggested to be incomplete leading to a higher peridermal water loss during consecutive months. In this study, we analysed morphological and anatomical parameters, peridermal conductance to water vapour and the level of native embolism in mid-winter and late-winter of lammas shoots and normal spring shoots of the apple varieties Malus domestica ‘Gala’ and ‘Nicoter’. Lammas shoots showed a significantly higher shoot cross-sectional area due to larger pith and corticular parenchyma areas. In contrast, phloem was significantly thicker in spring shoots. No pronounced differences were observed in xylem and collenchyma thickness or mean hydraulic conduit diameter. The phellem of spring shoots was composed of more suberinised cells compared to lammas shoots, which led to a significantly higher peridermal conductance in the latter. The amount of native embolism in mid-winter did not differ between shoot types, but in late-winter lammas shoots were more embolised than spring shoots. Data show that the restricted vegetation period of lammas shoots affects their development and, in consequence, their transpiration shield. This may also pose a risk for winter desiccation.