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1.
《林业科学研究》2019,(6)
[目的]通过研究新源县和巩留县野苹果林中疫霉菌的种类和致病性差异,为探讨新疆野苹果林衰亡原因提供基本资料,为野苹果林病害防治提供科学依据。[方法]采用疑似疫霉病害样品采集、土壤诱捕、林间溪流诱捕等方法对新疆野苹果林中的疫霉菌进行了调查采样和监测诱捕,并利用选择性培养基分离获得疫霉纯菌株。通过形态学观察和rDNA-ITS序列分析相结合的方法对所获得的疫霉菌株进行分类鉴定,并通过离体叶片接种试验对所鉴定的疫霉菌进行致病性测定。[结果]依据形态学特征和序列分析,鉴定得到5个种共计88株疫霉,分别为65株湖沼疫霉Phytophthora lacustris Brasier,Cacciola,Nechwatal,JungBakonyi、16株节水霉状疫霉Phytophthora gonapodyides(Petersen) Buisman、3株多寄主疫霉Phytophthora plurivora T. JungT. I. Burgess、2株聚疫霉Phytophthora gregata T. Jung,M. J. C. StukelyT. I. Burgess和2株Phytophthora sp.1。将前4种疫霉接种离体野苹果叶片后,发现它们均产生病斑,其中湖沼疫霉在离体叶片上产生的病症最为明显。[结论]新疆野苹果林中具有多种疫霉菌,且所鉴定的4种疫霉菌均对野苹果叶片有一定的致病性。 相似文献
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《西部林业科学》2019,(6)
为了给防治新疆野苹果病害提供生防性能优良的木霉菌株,利用孟加拉红平板分离法进行新疆巩留县野苹果根围木霉菌株分离,通过形态特征和ITS rDNA序列比对进行菌种鉴定,利用平板对峙试验检测分离木霉抑菌能力,用NBT染色和根部观察检验木霉诱导后新疆野苹果幼苗叶片活性氧含量、抗病和促生能力。结果表明:分离鉴定出俄罗斯木霉22株,渐绿木霉13株,哈茨木霉4株。从长势和产孢量等特性上看,俄罗斯木霉T7和哈茨木霉T2为新疆野苹果根围优势生防木霉菌种。哈茨木霉T2对尖孢镰刀菌的抑菌率为75.47%,对链格孢菌的抑菌率为78.17%。俄罗斯木霉T7对尖孢镰刀菌的抑菌率为79.66%,对链格孢菌的抑菌率为91.53%;NBT染色发现木霉处理后野苹果苗叶片活性氧含量降低,叶片染色颜色更浅。总之,木霉能有效抑制病原菌生长,能有效减少新疆野苹果幼苗中活性氧含量,促进和保护根系生长。本研究为防治新疆野苹果病害防治提供生防性能优良的木霉菌株,为苹果病害的生物防治提供可以借鉴的方法。 相似文献
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在伊犁地区免于寒流和干旱气流侵袭的河谷地带的山坡沟系中 ,分布有天然经济林——野果林。主要有野苹果、野山杏、野核桃、野樱桃李、欧洲李、山楂等。它们是第三纪古亚热带的遗留植被 ,是重要的种质资源。野果林在巩留、新源、尼勒克、霍城大西沟以及伊宁县等地均有分布 ,大多分布在海拔 80 0～ 160 0米的冬季温和的逆温层内 ,常与低山灌丛和草甸相结合 ,全地区现有野果林面积 0 .687万公顷。这些野果子 ,真可谓是“养在深山人未识”,现逐一介绍 ,以期更多的人有所了解 ,更希望有识之士“慧眼识真珠”,使之进入市场 ,促进当地经济发展。1… 相似文献
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[目的]分析同一采样地、同一生境新疆野苹果枯枝症状级别与水杨酸含量、胸径的关系,寻找与枯死症状可能相关的特征。[方法]通过超声提取、HPLC检测分析不同枯枝症状级别样品中水杨酸组成和含量差异,并对枯枝症状级别与水杨酸含量、胸径关系进行统计分析。[结果]不同枯枝症状级别的新疆野苹果枝叶中水杨酸含量在39.5～122.6 mg·kg~(-1)之间,含量差异显著(P0.05)。枯枝症状从0级到Ⅴ级,水杨酸含量存在先降低后升高的趋势。不同枯枝症状级别新疆野苹果胸径大小变异系数差异明显,Ⅴ级样品个体间胸径变异系数相对较大(39.18%);Ⅰ级样品变异系数相对较小(30.28%)。新疆野苹果水杨酸含量和胸径大小呈负相关(P0.05),其中,0级、Ⅴ级样品水杨酸含量和胸径大小呈正相关,Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级样品水杨酸含量和胸径大小呈负相关(P0.05)。[结论]新疆野苹果枯枝症状级别与水杨酸含量、胸径大小关系较为密切,研究结果对于天山野果林的生态保育与修复、苹果优质新品种的筛选与培育等具有一定的参考价值。 相似文献
6.
《林业科学研究》2021,(5)
[目的 ]杏树鬃球蚧在新疆野果林暴发成灾,对野杏生存和野果林生态环境造成重大危害。本研究揭示该虫在新疆野杏上的生物学特性,旨在为防控杏树鬃球蚧提供科学依据。[方法 ]2019年6月至2020年6月,在新疆巩留县和新源县通过室内实验和野外调查相结合,研究了杏树鬃球蚧的形态特征、生活史、习性。[结果 ]杏树鬃球蚧属于性二型昆虫,雌成虫呈半球形,雄虫有翅。在新疆野果林1年发生1代,主要以2龄若虫在枝条上越冬,越冬死亡率在65%以上,雌雄性比为1.02∶1。雌成虫平均产卵量527粒,卵的发育起点温度9.50℃,有效积温81.17 DD。杏树鬃球蚧在野杏树冠东、南、西、北4个方位的发生量无显著差异,主要分布在3年生枝条,且同一枝条阴面显著多于阳面。[结论 ]杏树鬃球蚧在新疆野果林的薄弱环节为2龄若虫出蛰期、膨大期(3月下旬至4月下旬)和1龄若虫涌散期(6月上、中旬),建议在此时期对该虫开展综合防治。 相似文献
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为给新疆野苹果抗寒性状的筛选提供理论依据,以新疆霍城县、巩留县、新源县、额敏县和托里县共5个地区野苹果林的叶片为研究对象,采用石蜡制片法制作切片,观察不同生境新疆野苹果叶片解剖结构,测量其叶片厚度、上表皮厚度、下表皮厚度、栅栏组织厚度、海面组织厚度、栅海比、叶片组织结构紧密度(CTR)、叶片组织结构疏松度(SR)等指标,分析其抗寒性差异。结果表明,托里县的叶片栅海比和CTR最大,SR最小,与其它4个自然居群野苹果叶片解剖结构存在显著差异(P0.05),表明其抗寒能力较强。5个自然居群新疆野苹果抗寒性由强到弱排序依次为:托里县野苹果、额敏县野苹果、巩留县野苹果、霍城县野苹果、新源县野苹果。 相似文献
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近年来，梨叶斑蛾危害渐趋严重，由于叶片被害，树势衰弱，抗病能力下降，导致腐烂病严重发生。梨叶斑蛾又称梨星毛虫，属鳞翅目斑蛾科，在我国东北、华北、西北、华中、华南均有发生，多以幼虫危害梨、苹果、海棠、花红、李、杏、桃、山楂等。 相似文献
10.
[目的]鉴定引起新疆巩留县杏树果实斑点病病原菌,研究造成杏树果实病害的原因,为当地杏树防治工作提供依据。[方法]采用常规组织分离法分离得到罹病杏真菌菌株,利用传统形态学观察和分子系统学分析相结合的方式对所分离出菌株进行分类鉴定及其致病性检测。[结果]杏果病斑处的病原菌在显微镜下观察到分生孢子形态与经PDA培养基培养后观察到分生孢子形态均与Thyrostroma carpophilum（Lév.） B.Sutton所产生分生孢子一致;将分离获得的3株真菌的rDNA-ITS片段测序后与NCBI参考序列进行多重序列比对的结果显示,其序列与T.carpophilum一致性为100%;在基于ITS基因序列构建的系统发育树中,3株菌与T.carpophilum聚在同一分支。在接种了T.carpophilum后,杏果实和叶片均产生明显病斑并且从其所产生的病斑上再次分离到所接菌,满足柯赫氏法则。[结论]从新疆巩留县杏果实病斑处分离获得的3株真菌,经鉴定为引起杏穿孔病的病原菌T.carpophilum。这是该菌首次在该地区发现并报道。 相似文献
11.
Our study focuses on predicting the ultimate short-term load carrying capacity of timber-to-timber connections with dowel-type fasteners. The wide range of possible configurations in practice makes the resolution of these values by tests unrealistic. Moreover, different current regulations do not consider some specific failure mechanisms. In many countries, the reduction of resistance involved by this phenomenon is taken into account by considering an effective number of dowels (nef) smaller than the actual number of dowels (n) in the connection. However, these different regulations disagree on the values of nef and on other points (spacing, partial coefficient of security, formulas). These discrepancies in design rules invite the fundamental research on this topic and, therefore, new methods are sought in order to estimate the load carrying capacities of the connections. In the light of these, our approach consists of predicting the load carrying capacity with the neural network numerical tool. The results obtained by this analysis tool are satisfactory, although the model remains complex. Subsequently, we focus on the simplification of this numerical model with classical regression techniques in order to implement it in a design code. 相似文献
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The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased
(moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol
timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod
filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to
25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by
biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent
of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis
is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol
can realise their production potential.'
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
13.
Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
Pavela R 《Fitoterapia》2004,75(7-8):745-749
The methanol extracts of eight species of medicinal plants were tested for insecticidal activity in third instar larvae of Egyptian cottonworm (Spodoptera littoralis). All extracts showed a certain degree of larval toxicity. The extracts of Ocimum basilicum, Origanum majorana and Salvia officinalis appeared to be highly toxic. The extracts significantly affected the growth indexes [relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD)]. 相似文献
15.
Trees and shrubs as sources of fodder in Australia 总被引：2，自引：0，他引：2
E. C. Lefroy P. R. Dann J. H. Wildin R. N. Wesley-Smith A. A. McGowan 《Agroforestry Systems》1992,20(1-2):117-139
Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline. 相似文献
16.
Adult fungus gnat and shore fly populations were monitored in four container nurseries near Victoria, British Columbia. In general, populations of both insects were larger in summer than in winter. Also, both insects were more abundant in the nursery with a plastic-covered, soil floor, which favored moisture accumulation and build up of algae, liverworts and mosses, than in nurseries with other types of floors such as cement. Results of fungus isolations revealed that gnats and flies both harbor the seedling pathogens Botrytis cinerea and species of Fusarium and Phoma, plus several non-pathogenic fungi. The results are discussed in relation to nursery sanitation practices, their effects on gnat and fly populations, and some possible roles of these insects in seedling disease epidemiology. 相似文献
17.
Carvacrol is a component of numerous aromatic plants. Up to now, no toxicological data were available. Carvacrol show a weak activity in the mutagenicity studies. Moreover, in the metabolism study, carvacrol has shown to be excreted with urine after 24 h in large quantities or unchanged or as glucoronide and sulphate conjugates. The available data do not allow the assessment of the NOEL. Further toxicological studies are needed. 相似文献
18.
Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
19.
This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old
stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual
trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over
100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase
of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen,
while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production
in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively
strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The
results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands,
e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce. 相似文献
20.
J. S. Kettler 《Agroforestry Systems》1996,35(2):165-176
The slash and mulch system of frijol tapado or covered bean is a pre-hispanic system of bean production found throughout much of Central America. However, land use pressures have forced farmers to shorten the traditional fallow period, thus resulting in decreasing productivity. A potential solution is to enrich the fallow by using leguminous nitrogen-fixing trees. The enriched fallow systems evaluated in this study include both single and mixed species treatments: 1) Erythrina poeppigiana; 2) Calliandra colothrysus; 3) Gliricidia sepium; 4) Inga edulis; 5) Inga edulis and Erythrina poeppigiana; 6) Inga edulis and Calliandra calothrysus; and 7) Inga edulis and Gliricidia sepium. Biomass production of the fallow vegetation is shown to be of greater quality and quantity in all fallow enrichment treatments. However, bean yields did not show a significant response to the fallow enrichment treatments. 相似文献