The response of Aporrectodea rosea and Aporrectodea trapezoides (Oligochaeta: Lubricidae) to moisture gradients in three soil types in the laboratory     

B. M. Doube  C. Styan 《Biology and Fertility of Soils》1996,23(2):166-172

The question of whether the response of earthworms to soil moisture is governed by their reaction to soil wetness (moisture content) or to soil water energy (matric suction) was examined in two species of earthworm using moisture gradients in three contrasting soil types with clay contents varying from 4 to 39%. Gravimetric moisture gradients ranging over 5–30% were established in horizontal cores comprising 12 or 14 sections containing loosely packed soil. Earthworms were introduced to each section at the beginning of each experiment. The earthworms moved from sections containing dry soil into adjacent sections containing moister soil. Clear effects were evident after 6 h but these became more obvious after 96 h. For the earthworm Aporrectodea rosea, the threshold soil mositure level at which earthworms were induced to move away from dry soil was a matric suction of about 300 kPa (pF 3.4) and was independent of soil type. In contrast, for A. trapezoides, the threshold soil moisture varied with soil type (sandy loam 15 kPa, loam 25 kPa, clay 300 kPa). We conclude that, for the earthworm A. rosea, matric suction and not water content of soil provided the cue by which the earthworm recognized dry soil. For A. trapezoides, there was an interaction between matric suction and soil type in which the response of A. trapezoides to soil moisture varied with soil texture and the threshold for avoidance of dry soil ranged from a matric suction of 300 kPa (20% w/w) in clay to 15 kPa (10% w/w) in sandy loam.  相似文献   

水肥耦合对荒漠区煤矸石山蜀葵和沙打旺水分利用效率的影响     

胡杭丽  王进鑫  马戌  万小楠  张龙廷  陈印  项通 《干旱地区农业研究》2022,40(4):143-150

为改善煤矸石山土壤水分和养分状况,提高景观生态型草本植物的水分利用效率,以蜀葵和沙打旺为试验材料,采用三因素五水平二次回归通用旋转组合设计,通过盆栽模拟试验研究了土壤相对含水量、施氮量、施磷量三者耦合对两种景观生态型草本植物叶片水分利用效率的影响,并通过模型寻优得出了最优水肥方案。研究表明：三因素对蜀葵叶片水分利用效率的影响顺序为土壤相对含水量＞施氮量＞施磷量,三因素对沙打旺叶片水分利用效率的影响顺序为土壤相对含水量＞施磷量＞施氮量;二因素耦合对蜀葵水分利用效率的影响不显著（P>0.05）,但对沙打旺水分利用效率有显著影响（P＜0.05）,其顺序为水氮＞水磷＞氮磷;土壤水分条件是影响蜀葵和沙打旺叶片水分利用效率的首要因素,施氮对蜀葵更重要,施磷对沙打旺叶片水分利用效率的影响更大,蜀葵的水肥耦合优化方案为土壤相对含水量37.6%~40.9%,施氮量（纯N）153.1~178.5 kg·hm^-2,施磷量（P₂O₅）89.4~120.4 kg·hm^-2;沙打旺的水肥耦合优化方案为土壤相对含水量69.0%~70.6%,施氮量（纯N）61.8~94.6 kg·hm^-2,施磷量（P₂O₅）109.9~170.1 kg·hm^-2。  相似文献   

红玫瑰挥发油化学成分研究   总被引：1，自引：0，他引：1  

张德志  高铁流  杨文胜  孙广仁  滕玉辉  张伟森 《吉林林学院学报》1992,(3)

本文利用GC/MS/DS联用技术对红玫瑰挥发油的化学成分进行了研究。在已分析的76种成分中鉴定了其中73种化合物,占总含量的98.54%。其主要成分是香茅醇(30.84%),β—笨乙醇(24.00%),香叶醇(20.11%)和丁香酚(3.88%)等。  相似文献   

蜀葵种子水浸液对西瓜和枸杞的化感作用     

张益民  薛泽 《中国农学通报》2012,28(10):179-182

研究蜀葵种子水浸液对西瓜和枸杞的化感作用,为植物化感作用的理论研究提供参考。采用生物测定法,用不同浓度的蜀葵种子水浸液处理西瓜、枸杞的种子和幼苗,研究其化感作用。结果表明：（1）不同浓度的蜀葵种子水浸液对西瓜种子萌发和幼苗生长均有不同程度的抑制作用,对枸杞幼苗的苗高、鲜重有促进作用;（2）当蜀葵种子水浸液浓度为0.005 g/mL、0.010 g/mL时对枸杞种子萌发和幼苗生长表现为化感促进作用,浓度为0.020 g/mL时对枸杞种子的发芽率、幼苗根长、根鲜重表现为化感抑制作用。综上,蜀葵种子水浸液可抑制西瓜种子的萌发和幼苗的生长,对枸杞幼苗的苗高、鲜重的增加有促进作用。  相似文献   

大斑芫菁和棉蝗间的发育同步性研究     

ZHU Fen    WANG Yong    ZHAO Fu    NIU Chang-Ying    LEI Chao-Liang 《昆虫天敌》2008,(3)

寄生物和寄主的发育关联研究已有很多报道,而人们对捕食者与猎物的同步发育关系却知之甚少。本文研究了大斑芫菁Mylabris phalerata及其猎物棉蝗Chondracris rosear osea在18℃、22℃、25℃、28℃、31℃和34℃恒温下的发育特性及发育同步性。大斑芫菁幼虫(除5龄外)发育起点温度均低于10℃,而棉蝗每个阶段的发育起点温度都高于10℃。大斑芫菁5龄幼虫的有效积温为440.53日度,低于棉蝗卵的462.96日度,并且大斑芫菁1～4龄幼虫的有效积温均少于1～4龄蝗蝻。大斑芫菁成虫出现、卵孵化和幼虫滞育解除日期与棉蝗产卵和卵孵化日期,显示大斑芫菁的发育和棉蝗的发育具有季节同步性,而且大斑芫菁的滞育同步化了大斑芫菁和棉蝗的发育。  相似文献   

Local spatial pattern in the occurrence of two congeneric wood-decaying fungi in an old-growth boreal forest     

《Scandinavian Journal of Forest Research》2012,27(5):393-399

Abstract

This paper characterizes spatial patterns in the occurrence of two congeneric wood-decaying fungi (Aphyllophorales: Polyporaceae) in an old-growth boreal forest in eastern Finland. The spatial patterns are used to evaluate indirectly the short-distance dispersal ability of the species. Fomitopsis rosea is a specialist on Picea abies occurring mainly in forests with large amounts of dead wood, whereas Fomitopsis pinicola is a substrate generalist and also abundant in managed forests. Within a forest reserve, a 25 ha study area was divided into 25 m×25 m grid (n=400), and all dead trees and fruiting bodies of the two polypore species were recorded. Spatial patterns were analysed with Spatial Analysis by Distance IndicEs methodology (SADIE). Downed spruce logs were highly aggregated within the study area. After this distribution was accounted for, the spatial pattern of F. pinicola and F. rosea on logs was random. The lack of spatial aggregation suggests that within old-growth forest stands dispersal of the two fungal species is not a limiting factor for their occurrence.  相似文献   

闽楠溃疡病病原鉴定及其生物学特性研究     

郭朦朦  陈全助  冯丽贞  杨泽慧  陆芝  冯锦秀  黄捷 《热带作物学报》2018,39(8):1601-1610

闽楠（Phoebe bournei）,我国Ⅱ级保护濒危植物,是亚热带常绿阔叶林重要组成树种,而闽楠溃疡病的发生严重危害其开发利用。为明确闽楠溃疡病的致病菌,以便后续科学的指导病害防治,本文从福建省闽楠病枝中分离纯化菌株,通过致病性测定、形态学观测以及 rDNA-ITS、GAPDH、β-tubulin、Histone3 序列分析鉴定病原菌,并分析其生物学特性。结果显示：从闽楠病枝中分离出 4 种菌株,分别编号为 SS-01、SS-02、SS-03 和 SS-04,其中菌株 SS-03 致病菌为粉红粘帚霉（Clonostachys rosea Schroers, et al.=Gliocladium roseum Bainier）;该菌菌丝在 PDA+PBL 培养基（pH 6.0）上 25 ℃黑暗条件下生长最好;最适菌丝生长碳源为麦芽糖,可溶性淀粉有利于产孢;最适氮源为牛肉浸膏;产孢量在 PDA 培养基（pH 7.0）上 25 ℃全黑暗条件最高。空气相对湿度≥90%（pH 8.0）时孢子萌发率最高。高温高湿以及高郁闭度易于闽楠溃疡病发生,故在营林造林以及苗圃抚育时应注意通风透气,控制温湿度,防止病害发生。该研究结果为科学有效地指导闽楠溃疡病防治提供技术支持。  相似文献   

Earthworm community structure on five English golf courses   总被引：1，自引：0，他引：1  

Mark Bartlett  Iain James  Jim Harris  Karl Ritz 《Applied soil ecology》2008,39(3):336-341

A clear understanding of the size and structure of earthworm communities is important to sports turf facilities managers if they are to control the activity of earthworms within the soil. Earthworms are directly linked to a wide range of biogeochemical nutrient cycles, and are frequently described as ecosystem engineers. In this role they assist land managers in maintaining a healthy turf sward. Despite this, earthworm populations in sports turf were frequently suppressed using organochloride based vermicides prior to such compounds being banned in the UK. A survey of earthworm species diversity was carried out over 1 year, using mustard extraction at five golf courses in Bedfordshire and Buckinghamshire, UK, to investigate how species diversity varied temporally and was influenced by the physical environment within different course surfaces. Rank–abundance analysis indicated that four species of earthworm (Aporrectodea rosea, Lumbricus rubellus, Aporrectodea longa and Lumbricus terrestris) were more dominant in the community than any other. The endemic earthworm population number of the five study sites was found to differ significantly (p < 0.01) related to their geographical location, and the most diverse communities were found where the population was greatest. A very strong linear correlation was found between the number of earthworms recovered and the sand content of the soil (r² = 0.97). Significant differences in the size of the earthworm populations were recorded at different times of the year (p < 0.01). A distinct and non-linear relationship between species diversity and microbial biomass C was shown (p < 0.01).  相似文献   

Development ofClonostachys rosea and interactions withBotrytis cinerea in rose leaves and residues     

Marcelo A. B. Morandi  Luiz A. Maffia  John C. Sutton 《Phytoparasitica》2001,29(2):103-113

The effect of microclimate variables on development ofClonostachys rosea and biocontrol ofBotrytis cinerea was investigated on rose leaves and crop residues. C.rosea established and sporulated abundantly on inoculated leaflets incubated for 7–35 days at 10°, 20° and 30°C and then placed on paraquat—chloramphenical agar (PCA) for 15 days at 20°C. On leaflets kept at 10°C, the sporulation after incubation on PCA increased from 60% to 93% on samples taken 7 to 21 days after inoculation, but decreased to 45% on material sampled after 35 days. A similar pattern was observed on leaves incubated at either 20° or 30°C. The sporulation ofC. rosea on leaf disks on PCA was not affected when the onset of high humidity occurred 0, 4, 8, 12 or 16 h after inoculation. However, sporulation was reduced to 54–58% on leaflets kept for 20–24 h under dry conditions after inoculation and before being placed on PCA. The fungus sporulated on 68–74% of the surface of leaf disks kept for up to 24 h at high humidity after inoculation, but decreased to 40–51% if the high humidity period before transferral to PCA was prolonged to 36–48 h. The growth ofC. rosea on leaflets was reduced at low inoculum concentrations (10³ and 10⁴ conidia/ml) because of competition with indigenous microorganisms, but at higher concentrations (10⁵ and 10⁶ conidia/ml) the indigenous fungi were inhibited. Regardless of the time of application ofC. rosea in relation toB. cinerea, the pathogen’s sporulation was reduced by more than 99%. The antagonist was able to parasitize hyphae and conidiophores ofB. cinerea in the leaf residues. AsC. rosea exhibited flexibility in association with rose leaves under a wide range of microclimatic conditions, and in reducingB. cinerea sporulation on rose leaves and residues, it can be expected to suppress the pathogen effectively in rose production systems.  相似文献   

温湿度对牛膝菊和红花月见草种子萌发的影响     

彭文君 朱茜李岳  汤东生 《中国农学通报》2012,28(1):158-161

为明确牛膝菊和红花月见草种子萌发对温度和温度的反应,开展了牛膝菊和粉花月见草在6种温度和5种湿度下种子的发芽势、发芽率和发芽指数的研究。结果表明,牛膝菊的最适萌发温度25℃,最适萌发温度为40%;粉花月见草的最适萌发温度为28℃,而最适萌发湿度也为40%。非最适温度和湿度对种子发芽势影响较大,降低了种子发芽指数。  相似文献