萧氏松茎象致病性白僵菌无纺布菌条的制作及培养基的筛选     

刘继生  肖斌  王丽娜  温小遂  唐艳龙  施明清 《江西植保》2008,31(3):99-102

分离培养采自安福县林间自然僵虫的白僵菌菌株,在液体和固体无纺布培养基上培养10d后的平均含孢量分别是1．09×10^8个·cm^-2。和2．01×10^7个·cm^-2,前者是后者的5倍。其在液体和固体无纺布培养基上24h后的平均萌发率分别为75．10％和71．86％。表明液体无纺布培养基更优于固体。  相似文献   

气候因子与温敏核不育系水稻花粉育性间的相关性研究     

宁金花  张艳贵  宋忠华 《安徽农业科学》2011,39(30):18446-18447,18468

在长沙自然条件下,于2010年观察准S、Y58S、P88S、培矮64S几个温敏核不育系水稻花粉育性变化,结合观察期的温度变化进行育性稳定性、育性对温度的敏感时期以及不育度与不同温度极值之间的相关分析。结果表明,准S的花粉育性稳定性最好,有2个敏感期,分别是抽穗前3～0 d和24～6 d;P88S有1个敏感期,为抽穗前12～19 d;58S有2个敏感期,为18～17和25～24 d;64S有2个敏感期,为抽穗前25～21和8～0 d。不同温度值和花粉不育性相关性不尽相同,以最高温、最低温、温差和日均温为指标与育性进行相关分析得到的温度敏感期基本一致,但也存在一定差异,主要表现在敏感期长短和显著性差异上。  相似文献   

青藏高原蕨麻种质资源遗传多样性POD同工酶分析     

刘贺贺  蒋红霞  富贵  白世俊  包锦渊  韦梅琴  李军乔 《西北农业学报》2016,25(3):413-422

采用聚丙烯酰胺凝胶电泳技术分析75份蕨麻过氧化物同工酶,结果与形态学标记、细胞水平、分子标记研究的结果一致,显示蕨麻的遗传多样性丰富。证实蕨麻具有丰富遗传变异,为合理保护与科学利用蕨麻资源提供科学依据。检测显示,蕨麻叶片过氧化物同工酶电泳共出现14条酶带;酶带多态位点百分率为100%;NTSYSpc 2.1软件计算的遗传相似系数为0.214~1.000,平均值为0.681;以遗传相似系数为基础,采用非加权类平均法进行聚类分析,在相似系数为0.67时分为2大类,第1类为蕨麻,第2类为鹅绒委陵菜。蕨麻种质资源遗传多样性及遗传变异均较丰富。说明,蕨麻丰富的遗传多样性是在青藏高原复杂的地理环境中长期进化的结果。  相似文献   

太子山自然保护区主要乔灌木树种分布规律初探     

柳文斌  段红梅 《甘肃林业科技》2009,34(4):20-22

为深入了解太子山自然保护区主要乔灌木树种的分布状况,摸清辖区木本植物资源的具体数量、质量及结构,更好地指导林业生态建设,通过开展专项调查及历史资料的引用分析,表明保护区主要乔灌木树种在垂直及水平分布上具有一定规律性,凸现了生物物种自然选择特征。  相似文献   

Impacts of summer versus winter logging on understory vegetation in the Chequamegon-Nicolet National Forest     

Amy T. Wolf  Linda Parker  Gary Fewless  Kathryn Corio  Juniper Sundance  Robert Howe  Heather Gentry 《Forest Ecology and Management》2008

In seasonal climates the timing of logging operations can be adjusted to avoid the major growing periods of understory plants and seedlings. We evaluated the understory vegetation at five pairs of hardwood-dominated sites in northern Wisconsin, U.S.A. where one site in each pair was logged during winter and the other during summer. All sites were dominated by sugar maple (Acer saccharum) and basswood (Tilia americana), with varying amounts of other native tree species. Most (84%) of the 247 vascular plant species recorded during the study are indigenous to the region. Winter-logged sites supported significantly higher numbers and percent cover of ecologically vulnerable native plant species as defined by independently established coefficients of conservatism. These differences between winter-logged and summer-logged sites suggest that winter logging may have fewer negative impacts than summer logging on vulnerable plant species and, in the long run, may help maintain plant biodiversity in managed forests of this region. In both types of sites, understory plant richness and diversity were significantly higher near logging roads, due largely to higher numbers of alien species and early successional native plants. Away from roads, neither species richness nor diversity differed between winter-logged and summer-logged sites. Studies that fail to account for differences in species composition and studies that fail to include samples of access roads or skid trails are likely to ignore important impacts of logging activities.  相似文献   

水稻及其敏感突变体苯达松抗性的生理生化差异研究   总被引：1，自引：0，他引：1  

王云生  陆徐忠  孙明娜  宋丰顺  李莉  高同春  杨剑波 《作物学报》2008,34(9):1615-1623

苯达松敏感致死(bentazon sensitive lethal, bsl)基因在杂交水稻(Oryza sativa L.)混播制种和杂交稻种纯度鉴定等方面具有广阔的应用前景。以水稻品种农林8号(N8)、W6154s和其对应的bsl突变体农林8号m (N8m)和8077s为材料, 分析了苯达松处理对叶片中叶绿素(Chl)含量、丙二醛(MDA)含量、氧自由基含量、净光合速率(P_n)、叶绿素荧光参数等生理生化指标的影响及苯达松含量的变化, 旨在揭示水稻苯达松抗性差异的生理机制。结果表明, 苯达松处理使bsl突变体叶片光系统II中还原性Q_A组分积累, 光合电子传递受阻, 光合能力丧失, 氧自由基伤害积累, Chl降解、质膜氧化加剧, 植株死亡。叶片中苯达松残留含量分析表明, 较强的苯达松代谢能力是抗性品种免受苯达松伤害的主要原因。  相似文献   

一种提高作物产量杂种优势的亲本选配方法——以棉花为例     

潘春桂 《安徽农业科学》2017,45(7)

[目的]研究棉花双亲间一些产量性状的差异与杂种一代产量中亲优势的变异性。[方法]采用半双列杂交方法配制36个组合,按照随机区组方法进行设计。[结果]双亲铃重均匀度和单株成铃数是棉花产量杂种优势变化的敏感性状,提高全株铃重均匀度的双亲差异或减小单株成铃数的双亲差异,均可使产量中亲优势变异加大。[结论]该研究为选育产量强优或超强优杂种一代提供理论依据。  相似文献   

土地利用分类中OLI影像合成最佳波段组合研究   总被引：1，自引：0，他引：1  

晁增福  邢小宁  康顺光 《湖北农业科学》2017,56(8)

为了将Landsat8_OLI遥感影像应用于土地利用分类中,以新疆维吾尔自治区阿拉尔市Landsat8_OLI遥感影像为试验数据,在对试验数据进行光谱特征分析的基础上,采用最佳指数(OIF)法对Landsat8_OLI遥感影像合成最佳波段组合进行了研究。结果表明,Landsat8_OLI数据各波段中,Band5包含的地物信息最丰富;Landsat8_OLI最佳波段组合为OLI457,其结果具有较好的目视效果。  相似文献   

DNA methylation changes in fusarium wilt resistant and sensitive chickpea genotypes (Cicer arietinum L.)     

《Physiological and Molecular Plant Pathology》2015

DNA methylation plays an important role in the regulation of gene expression in biotic and abiotic stresses. In the present study, a methylation-sensitive amplified polymorphism (MSAP) analysis was performed to profile DNA methylation changes in seven resistant and sensitive chickpea genotypes following inoculation with Fusarium oxysporum f. sp. ciceris. In all, 27468 DNA fragments, each representing a recognition site cleaved by either or both of two isoschizomers, were amplified using nine selective primer pairs. DNA methylation was evaluated in leaves, stems and roots in control and inoculated plants. Extensive cytosine methylation alterations were found in the pathogen-treated genotypes compared with the corresponding control, including hypermethylation and demethylation as well as the potential conversion of methylation types. For all genotypes, the percentage of demethylated sites were more than methylated sites in infected plants compared with the corresponding control. No significant differences were observed for banding patterns in infected and control leaf tissues, while the differences between percentage of unchanged, methylated and demethylated sites were significant in stem and root tissues. The total numbers of methylated polymorphic bands ranged from 137 to 154 bands in Sel95th1716 and Arman, accounting for 36.81%–44.64% of all bands, respectively. Ten fragments that were differentially amplified between infected and control plants were isolated and sequenced in three tissues separately. Most of sequenced fragments showed homology with disease related genes in GenBank. The results suggest that significant differences in cytosine methylation exist between resistant and sensitive chickpea genotypes, and that hypermethylation or hypomethylation of specific genes may be involved in the chickpea resistance to Fusarium wilt.  相似文献   

An integrated recirculating aquaculture system (RAS) for land-based fish farming: The effects on water quality and fish production   总被引：2，自引：0，他引：2  

Shi-Yang ZhangGu Li  Hui-Bi WuXing-Guo Liu  Yan-Hong YaoLing Tao  Huang Liu 《Aquacultural Engineering》2011,45(3):93-102

To mitigate the serious water pollution caused by the rapid expansion of the aquaculture industry in recent years, the development of improved aquaculture systems with more efficient water usage and less environmental impact has become essential. In this study, a land-based recirculating aquaculture system (RAS) was established that consisted of purification units (i.e., a primary biological pond, two parallel horizontal subsurface flow constructed wetlands [CWs], and a long ecological ditch) and 4-5 series-connected recirculating ponds. This system was mainly designed to stock channel catfish (Ictalurus punctatus), fifteen spine stickleback (Spinibarbus sinensis) and yellow catfish (Pelteobagrus fulvidraco), and the culture efficacy was evaluated based on a 2-year field experiment covering two growing seasons. According to the results, the primary biological pond played a role in sedimentation or nutrient retention, although this was not as evident when the CWs were functioning. The water flowing through the wetland system at a hydraulic loading rate (HLR) of 600 mm/day displayed lower values for the temperature, pH, dissolved oxygen (DO), suspended solids, organic matter and nutrients, whereas the electrical conductivity (EC) was higher, suggesting the accumulation of dissolved solids in the system. Due to the recirculation treatment, the trophic status of the recirculating ponds increased gradually along the direction of the flow and was notably lower in comparison to the control. As a result, the fish production responded to the variation of the water quality, which was reflected in the measurements of culture efficacy (final weight, survival rate, SGR and yield). The three main rearing species showed a decreasing trend along the direction of the flow, which was higher compared to the control, whereas an opposite trend was observed for filter-feeding fish. A Pearson correlation analysis revealed that the main culture species were inclined to live in meso- or oligotrophic conditions, and the silver carp adapted to more eutrophic conditions. Because RAS can provide better environmental conditions year-round, the present culture method could be more suitable for species that are sensitive to water quality in typical subtropical areas.  相似文献