Altitudinal and longitudinal variations in Pinus brutia (Ten.) of Crete Island,Greece: some needle,cone and seed traits under natural habitats

Four populations representing the entire natural distribution range of Pinus brutia (Ten.) in Crete (Greece) were sampled to determine: (1) Altitudinal variation within populations of Lassithi, Vorizia, Koustagerako, and Samaria, and; (2) Longitudinal variation among the four populations, based on morphological and anatomical differences in cone, needle and seed characteristics. Samples were collected from 10 trees per altitude, at three altitudes in each population. A total of 12 morphological and anatomical traits from needles, cones and seeds were analyzed to assess the altitudinal and longitudinal variations of the species in the island. The number of teeth per cm showed significant (P<0.01) differences between altitudes in Samaria, Vorizia and Lassithi, while needle length, width and the number of resin canals showed significant differences (P<0.01) between altitudes in Koustagerako. Cone width showed patterns of variation along the altitudinal gradient in Koustagerako, Samaria and Vorizia. Most traits had their highest means at the middle altitudes (650masl) in all the four populations. Overall, no clear altitudinal differentiation was detected, probably due to high rate of gene flow. Longitudinal variability showed a clear pattern of differentiation along the east–west climatic gradient. Needle length, width, sheath length, number of teeth per cm and the number of resin canals were the most useful traits for determining the climatic gradient clines.     

Seasonal population dynamics of Typhlodromus pyri Scheuten (Acari, Phytoseiidae) in apple orchards in the region Meckenheim

Typhlodromus pyri Scheuten (Acari, Phytoseiidae) has been reported as the most important predator of the European red mite, Panonychus ulmi (Koch) (Acari, Tetranychidae) in apple culture. However, biological data on T. pyri was insufficient on important parameters like seasonal population dynamics and within-tree and on-leaf distribution in apple orchards in the region of Meckenheim, Germany. The purpose of the present work was, therefore, to obtain experimental data on these parameters of T. pyri from 2000 to 2002 in the apple orchards in this region. The results showed that overwintered females of T. pyri reactivate and start laying eggs between late March and early April. The mean daily number of the different stages of T. pyri per leaf peaked in July each year, where it ranged between 0.92–1.68 eggs, 0.81–1.41 nymphs, 0.64–1.32 females and 0.37–0.52 males. A significantly higher number of T. pyri individuals congregated in the bottom layer of trees (0.34–0.64 individuals/leaf) than in the middle and top layers (0.23–0.38 and 0.12–0.23 individuals/leaf, respectively). We found that 91.4–94.1% of the total eggs, 89.6–91.7% larvae, 73.0–76.5% nymphs, 60.5–64.6% adult females and 52.6–55.9% adult males concentrated their activities in the inner area of the leaf surface. More than 50% of the predatory mites congregated in the bottom layer in winter. Mean total density of the overwintering females in December of 2000,2001 and 2002 ranged between 10.6–14.2 females/5 cm twig in the bottom, 7.3–10.4 in the middle and 4.1–6.9 in the top layers of the apple trees. Mean total fecundity recorded over the 3 years was lowest in the overwintering generation with 31.8–37.6 eggs/female, highest in the June generation with 45.9–53.7 eggs/female, and intermediate in the August generation with 41.5–46.1 eggs/female. The overwintering generation was composed entirely of females, while the female to male ratio in the June generation was 2:1, and in the August generation 3:1. T. pyri overwinters as adult females in rough structures, cracks and crevices of twigs.     

Genetic differences between autochthonous and breeding populations of common cypress (Cupressus sempervirens L.) in Greece

Individuals were selected for resistance against the imperfect fungus Seiridium cardinale Wag in six common cypress populations (Cupressus sempervirens L.) in Greece. A total of 109 resistant clones and 140 trees from their base populations were surveyed at several allozyme loci. The comparison yielded information on changes in genetic variation due to artificial selection. The genetic structure of the breeding populations was similar to their base populations. Nevertheless, the number of rare alleles among the resistant clones had decreased, showing a similar trend at most loci and for most comparisons. Possible implications for breeding strategies are discussed.     

Structure and regeneration dynamics of dominant tree species along altitudinal gradient in a dry valley slopes of the Bhutan Himalaya

The aim of our study was to characterize the structure and regeneration dynamics of dominant tree species along altitudinal gradient in dry valley slopes of the Bhutan Himalaya. In the typical dry valley slopes of west-central Bhutan, we analyzed forest stratification, tree crown projection, and population structure from lower dry valley bottom (1520 m a.s.l.) to upper humid ridge top (3370 m a.s.l.) across five major forest types: i.e. (1) dry pine forest with Pinus roxburghii as a dominant species; (2) mixed broad-leaved forest with Quercus lanata (evergreen), Quercus griffithii, (deciduous), and Rhododendron arboreum (evergreen) as major canopy species; (3) evergreen broad-leaved forest dominated by Quercus semecarpifolia, Quercus glauca and Quercus oxyodon; (4) cool conifer forest dominated by Abies densa and Tsuga dumosa; (5) cold conifer forest with A. densa and Juniperus recurva as dominants. In general, regeneration pattern of major dominant species shifted from inverse-J (lower altitudes), to sporadic (mid-altitudes), and to uni-modal type (upper altitudes) corresponding to three regeneration trends: (1) invasive at the lower, warm, dry forest under relatively strong human disturbances; (2) stable/balanced at the mid-altitude, in a relatively stable, mature moist evergreen broad-leaved forest with gap regeneration; and (3) poor/low regeneration at the upper, cool, humid conifer forest with a continuously cattle-grazed understory. Overall, regeneration patterns were balanced in all forest types, however care should be taken to prevent excessive exploitation of dry pine forest of lower valley bottom, and to control cattle grazing at higher altitudes. Our findings can be incorporated into management plans for sustainable management and conservation of mountain forests.     

巴山木竹种群生物量结构研究

研究了陕西镇巴县巴山木竹种群的生物量结构.结果表明:(1)该巴山木竹种群生物量在各构件单位的分配为秆55.56%,叶3.40%,枝9.51%,鞭8.70%,蔸20.77%,根2.06%;地上部生物量在各年龄的分配1～5年生的分别为19.0%,5.2%,5.4%,4.3%,8.9%,6和7年生的14.6%,8和9年生的18.2%,10a及以上的24.4%;地下部生物量在各土层中的分配是0～2cm的12.9%,20～40cm的43.1%,40cm以下的44.0%.(2)3年生及以下幼龄竹和8年生及以上老龄竹的平均秆重低于标准秆重,4～7年生竹的高于标准秆重.(3)随着竹子幼龄-中龄-老龄的年龄变化,单分株叶构件的绝对重量及其与秆重的比值皆有上升-稳定-下降的变化趋势.     

白蜡虫优良种虫及种群性比组成的研究

白蜡虫(Ericerus pela Chavannes)是我国特产资源昆虫,国内产区很多。实验表明各产区繁育白蜡虫的产量与质量差异显著,其中以金沙江下游云、贵、川三省相接壤的白蜡虫产区,繁育的白蜡虫产卵数量多、雄卵比率高、产蜡时间长、产蜡量多,同时蜡虫的产量高,是我国白蜡虫的优良种虫。     

夏大豆干物质生产、光合生理特性对群体调控的反应

试验设置12.75万、15.75万、18.75万、21.75万、24.75万株/hm~2 5个群体密度,研究了夏大豆干物质生产、光合生理特性对群体调控的反应。结果表明同一生育时期随群体密度的增加单株干物质积累量、各器官分配比重、叶绿素相对含量、产量性状呈下降趋势,叶面积指数随着生育进程的推进呈现先增加后降低的单峰抛物线变化趋势,鼓粒期达到峰值后开始下降。在12.75万～24.75万株/hm~2群体密度范围内,产量随群体密度的增加呈现先增加后降低趋势,18.75万株/hm~2产量最高达3 029.58 kg/hm~2。     

Alcohol diluent provides the optimal formulation for calcium chloride non-surgical sterilization in dogs

Background

Surgical castration is widely used to sterilize male dogs, but has significant impacts on time to perform the operation, recovery of the animals as well as cost, which can limit population control programs. Previous research has shown intratesticular injection of calcium chloride dihydrate (CaCl₂) in saline to be a promising alternative to surgery. However, long-term azoospermia was not maintained at dosages low enough to avoid side effects. In the search for an optimized formulation, the current investigation is the first study on long-term sterilization effects of intratesticular injection of CaCl₂ in either lidocaine solution or alcohol in dogs. CaCl₂ at 20% concentration in lidocaine solution or alcohol was administered via intratesticular injection to groups of 21 dogs each. The treated animals were examined at 2, 6, and 12 months for sperm production, blood levels of testosterone, and side effects; at time zero and 12 months for testicular size and semen volume. The experimentally treated animals were compared to a control group receiving saline injection only.

Results

Testicles of dogs treated with CaCl₂ in either diluent significantly decreased in size. After administration of CaCl₂ in lidocaine solution, sterility was achieved for at least 12 months in 75% of treated dogs. However, optimal long-term contraceptive effectiveness was achieved with CaCl₂ in alcohol, which resulted in azoospermia over the 12-month study period. Testosterone levels significantly decreased following treatment with CaCl₂, and sexual activity disappeared. Although testosterone returned to baseline levels by 12 months for the group treated with CaCl₂ in lidocaine, dogs injected with CaCl₂ in alcohol had a 63.6% drop in testosterone level, which remained at the low end of physiological range throughout the study. No adverse effects were noted.

Conclusions

A single, bilateral intratesticular injection of 20% CaCl₂ in 95% ethanol was a reliable method for induction of sterilization in 18–28 kg male dogs in this study. The approach showed long-term efficacy and reduced sexual behavior. This chemical method of sterilization might provide an effective, efficient alternative to surgical castration that can have positive impacts on dog welfare.     

尼罗非鲫和奥利亚非鲫线粒体DNA遗传差异的研究

以酶切MitochondrialDNA（mtDNA）技术检测了尼罗非鲫和奥利亚非鲫的mtDNA。测得两种鱼线粒体基因组的大小都约为16．83kb。在使用的6种酶中，只有PvuⅡ在所检测的15尾尼罗非鲫mtDNA上产生了多态片段，3尾鱼的mtDNA产生了4个片段，12尾鱼的mtDNA产生3个片段。而6种酶在所有15尾奥利亚非鲫中均未检到多态片段。比较两种鱼的mtDNA酶切片段，仅PvuⅡ的酶切结果有所不同，尼罗非鲫mtDNA上有3个或4个PvuⅡ位点，但奥利亚非鲫mtDNA上有5个位点，因此，PvuⅡ的酶切位点可作为鉴别它们的分子遗传标记。     

胶州市小麦禾谷孢囊线虫群体动态的年度间差异

为明确山东胶州市禾谷孢囊线虫(Heterodera avenae,CCN)的田间发生状况及其年度间的差异,于2011-2012和2012-2013年两个小麦生长季在该地区麦田进行定点定期取样、土壤中线虫分离和根组织内线虫染色后镜检,以确定各虫态的季节和年度间群体动态变化。结果表明,与2011-2012年相比,2012-2013年春季CCN 2龄幼虫(J2)孵出较早,但对根系侵入较晚;土壤中J2群体密度较高,根组织中反而较低;根内幼虫发育不良,表现为3龄和4龄幼虫发生较晚且持续时间较短,没有明显发生高峰,群体密度持续低下;小麦收获后土壤中孢囊密度减少85.9%。2012-2013年J2侵入期推后和侵入率下降与3-4月份土壤干旱有关,而根内幼虫发育不良与4-5月份气温偏低有关。因此CCN侵染和发育关键期的干旱和低温可能是造成孢囊密度下降的主要原因。