新疆杨树用材林固碳能力分析   总被引：1，自引：0，他引：1  

李丕军  李宏  马江林  李基勇 《西南林学院学报》2011,31(3):41-44

以第4次森林资源连续清查数据为依据,用蓄积量法对新疆杨树用材林的各龄组进行固碳能力分析,结果显示：新疆杨树用材林的总面积是7200hm2,总蓄积量594600m3,总固碳量达792495．93t;各龄组固碳量分别为近熟林占67．84％,中龄林占13．61％,幼龄林占18．55％;各龄组的单位蓄积量以及碳密度均是近成、过熟林大,中龄林最小。  相似文献   

Comparison of Yellow and Blue Sticky Cards for Detection and Monitoring Parasitoid Wasps of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae)     

Mark Cody Holthouse  Lori R Spears  Diane G Alston 《Journal of insect science (Online)》2021,21(5)

The invasive Halyomorpha halys (Stål) is a significant agricultural and urban nuisance pest in many parts of the world. In North America, biological control of H. halys by parasitoid wasps in the families Scelionidae and Eupelmidae has shown promise. An effective technique for detection and monitoring native and exotic parasitoids is the deployment of yellow sticky cards; however, yellow cards also attract nontarget arthropods, reducing efficiency and accuracy of parasitoid screening. This study sought to identify an alternative yet effective trapping technique by comparing the number of target parasitoid wasps [Anastatus spp. Motschulsky (Hymenoptera: Eupelmidae), Telenomus spp. Haliday (Hymenoptera: Scelionidae), and Trissolcus spp. Ashmead (Hymenoptera: Scelionidae)] and arthropod bycatch on yellow and blue sticky cards deployed in urban, orchard, and vegetable landscapes in northern Utah from late May to early October in 2019 and 2020. Yellow sticky cards captured 54–72% more target parasitoids than blue cards from June through August in all three landscape types in both years; however, a positive correlation in parasitoid capture indicated blue cards detect target parasitoids, just in fewer numbers. Both card colors detected adventive Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) in initial findings of 2019, and in expanded locations of 2020. Furthermore, blue cards captured 31–48% less Diptera and nontarget Hymenoptera than yellow cards in both years across all three landscapes, translating to reduced card processing time and impacts to beneficial insect populations. Our results suggest that blue vs yellow sticky cards offer an alternative monitoring technique to survey for H. halys parasitoids.  相似文献   

The effect of tillage systems on some microbial characteristics     

O. Mikanov  M. Javrek  T. &#x;imon  M. Friedlov  M. Vach 《Soil & Tillage Research》2009,105(1):72-76

Soils were sampled from plots with four variants of tillage methods: (1) conventional tillage (CT); (2) no tillage (NT); (3) minimum tillage (MTS); and (4) no tillage + mulch (NTM). Our aim was to study the influence of tillage on selected soil microbial properties. Determination of urease, dehydrogenase, invertase, arylsulphatase, potential nitrogenase activity, CFU of Azotobacter spp., and carbon microbial biomass has been conducted for time period 2002–2007. Soil samples from 0–0.1 m, 0.1–0.3 m, and 0.3–0.5 m were collected in the spring and autumn. Enzymatic activities (dehydrogenase, urease, arylsulphatase, and invertase) were significantly affected by soil depth and the tillage system employed. The statistically significant higher activity of urease was measured using the minimum tillage system (MTS), compared to the conventional tillage (CT) at soil depths of 0–0.1 m. The highest dehydrogenase activity was measured during the protective tillage treatment (NTM – no tillage with mulch). As far as other enzymatic activities (invertase and arylsulphatase) are concerned, the highest values were recorded in the protective tillage treatments. The highest counts of Azotobacter spp., as well as the highest nitrogenase activity (both statistically significant) were found in the no tillage + mulch (NTM) variant, at depths of 0.1–0.3 m. Microbial biomass (C-biomass) was the highest with the minimum tillage (MTS). The results show a positive influence of protection soil tillage on the reviving of upper layer of topsoil, especially in the variants where soil was supplied with organic matter.  相似文献   

Genetic identity and relationships of Iranian apple (Malus?×?domestica Borkh.) cultivars and landraces, wild Malus species and representative old apple cultivars based on simple sequence repeat (SSR) marker analysis     

Ali Gharghani  Zabihollah Zamani  Alireza Talaie  Nnadozie C. Oraguzie  Reza Fatahi  Hassan Hajnajari  Claudia Wiedow  Susan E. Gardiner 《Genetic Resources and Crop Evolution》2009,56(6):829-842

In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25 alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics, gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major players in apples’ domestication and transfer from Central Asia to the western countries.  相似文献   

Cause and duration of mustard incorporation effects on soil-borne plant pathogenic fungi     

Hanna Friberg  Véronique Edel-Hermann  Nadine Gautheron  Vincent Faloya  Christian Steinberg 《Soil biology & biochemistry》2009,41(10):2075-7890

Two fungal plant pathogens, Rhizoctonia solani AG 2-2 and Fusarium oxysporum f.sp. lini, were studied in relation to general responses of soil fungi and bacteria following incorporation of Brassica juncea. Our aim was to understand to what extent the changes in the biological and physicochemical characteristics of the soil could explain the effects on the studied pathogens and diseases, and to determine the temporal nature of the responses. Short-term effects of mustard incorporation (up to 4 months) were investigated in a microcosm experiment, and compared with a treatment where composted plant material was incorporated. In a field experiment, the responses were followed up to 11 months after removal or incorporation of a mustard crop. In general, responses in the variables measured changed more after incorporation of fresh mustard material than after addition of similar amounts of composted plant material (microcosms) or after removal of the mustard crop (field). The soil inoculum potential of R. solani AG 2-2 decreased directly after incorporation of mustard, but increased later to disease levels above those in the untreated soil. Neither of these effects could be explained by changes in the population density of R. solani AG 2-2. Fusarium spp. were less influenced, although an increase in the suppressiveness to Fusarium wilt was observed after mustard incorporation as compared with the treatment where mustard was removed. The microbial responses to mustard incorporation were more pronounced for bacteria than for fungi. After an initial substantial increase, the bacterial density decreased but remained above the levels in the control treatment throughout the experimental periods. The bacterial community structure was modified up to 8 months after mustard incorporation. We conclude that incorporation of fresh mustard influences soil microbial communities, especially the bacteria, and has a potential to control the pathogenic activity of R. solani 2-2 on a short-term perspective. The time dependency in microbial responses is important and should be taken into consideration for the evaluation of the potential of Brassicas to control plant disease on a field scale.  相似文献   

植物内生真菌镰刀菌对马铃薯晚疫病菌的抑制研究^*   总被引：2，自引：0，他引：2  

苏珍珠  罗文富  杨艳丽  杨子祥 《云南农业大学学报(自然科学版)》2009,24(5):667-672

 鉴定了分离自7种植物上的11株内生真菌镰刀菌并研究了它们对马铃薯晚疫病菌的抑菌活性。对峙培养试验表明：11株内生真菌镰刀菌对该病菌均有抑制作用,其中菌株e060-1, e060-3,e060-4的抑制率达50%以上。这些内生真菌镰刀菌的毒素粗提液对该病菌菌丝生长有更明显的抑制作用,其中e012-3,e060-4和e032毒素粗提液的抑菌率达100%。毒素粗提液能明显抑制晚疫病菌孢子对离体叶片的侵染,其中菌株e032毒素粗提液的抑制率达971%。  相似文献   

西瓜细菌性果斑病拮抗内生细菌的分离和筛选   总被引：2，自引：0，他引：2  

蔡学清  鄢凤娇  林玉  胡方平 《福建农林大学学报(自然科学版)》2009,38(5)

从葫芦科作物及空心菜的叶片、茎及花上共分离到95个菌株,采用抑菌圈法共筛选到对西瓜细菌性果斑病病原菌具有不同程度拮抗作用的菌株46株,占分离菌株总数的48.4%;从拮抗菌株中筛选出5株对西瓜细菌性果斑病菌具有较好拮抗效果的菌株,其对西瓜细菌性果斑病的防治效果为68.75%-93.24%.内生性测定结果表明这5株菌株均能在西瓜体内定殖,5株菌株经过革兰氏染色、鞭毛染色、芽孢染色和一些生理生化测定,初步被确定为芽孢杆菌属(Bacillus spp.).  相似文献   

甘肃省半干旱灌区苜蓿地土壤镰刀菌群落结构研究     

孟嫣  李敏权 《安徽农业科学》2009,37(23):11119-11120

[目的]研究甘肃省半干旱灌区苜蓿地土壤镰刀菌群落结构。[方法]将采自甘肃农业大学苜蓿试验地的土样进行分离、鉴定。[结果]共得到10个属的81株镰刀菌,分别为：茄病镰孢（F.solani）、串殊镰（F.monilifrorme）、尖孢镰孢（F.oxysporium）、燕麦镰孢（F.avernaceum）、接骨木镰（F.sambucium）、半裸镰孢（F.semitectium）、潮湿镰孢（F.udum）、三线镰孢（F.tricinctum）、雪腐镰孢（F.nivale）、木贼镰孢（F.equiseti）。[结论]为进一步开发利用镰刀菌资源提供科学依据。  相似文献   

赤眼蜂滞育研究及应用进展   总被引：2，自引：0，他引：2  

张俊杰  孙光芝  杜文梅  阮长春 《吉林农业科学》2009,34(1)

赤眼蜂滞育技术的研究对赤眼蜂工厂化生产及应用具有重要的意义。本文综述了人工诱导赤眼蜂滞育的环境因子和内在因素对滞育的影响,低温是引起赤眼蜂滞育的最主要因素,光周期是诱导赤眼蜂滞育的另一重要因素。与此同时,母代效应、寄主、诱导时期等也都影响着赤眼蜂滞育,因此针对不同的蜂种必须综合考虑各方面因素才能设计出高效、稳定的滞育诱导措施。  相似文献   

芽孢杆菌SH6-1的分离鉴定及其生物活性测定     

李纪顺  陈凯  扈进冬  王召娜  杨合同 《河南农业科学》2009,(10)

菌株SH6-1分离自山东省寿光大棚黄瓜根际土中,经16S rDNA序列分析及常规生理生化测定,将其鉴定为巨大芽孢杆菌。菌株SH6-1具有较好的固氮、解磷、解钾能力,培养5d后发酵上清液的含氮量为3.573μg/mL,KCl含量为9.139μg/mL,培养2d后发酵上清液的P2O5含量为2932.5μg/mL。在温室条件下,菌株SH6-1对小麦株高及鲜重增加率分别为8.8%、33.8%,对番茄株高及鲜重增加率分别为12.2%、15.4%,对小麦纹枯病和番茄立枯病的防治效果分别达到了57.8%、61.7%。  相似文献