常州市钟楼区耕地产能空间分布与影响因素分析

耕地产能评价对于耕地资源保护及质量提升具有重要的现实意义。通过构建耕地产能评价体系，运用空间自相关及主成分回归分析法对常州市钟楼区的耕地产能进行空间分布及影响因素分析。结果表明：基于气候、自然因素和技术水平综合指标的耕地产能评价体系具有适用性和可操作性；钟楼区耕地产能等别分为6等和7等，其中6等地占比达到97.55%，等别空间分布呈现出城区内部街道低、外围地区较高的格局；耕地产能整体空间集聚性显著，各街道（乡镇）均表现出较强的空间正相关性，正相关类型（HH型和LL型）多呈现组团式，负相关类型（LH型和HL型）则分布零散；耕地自然质量和技术水平是影响钟楼区耕地产能空间分布的主要驱动因素，其中，耕作层厚度、有机质含量、障碍层距地表深度和土壤养分元素为主导因素，pH值、灌溉保证程度和排水条件为次要因素。因此，应从增强耕地自然质量、提高耕地技术水平等方面制定提高耕地产能的针对性措施。     

The priority of management factors for reducing the yield gap of summer maize in the north of Huang-Huai-Hai region,China

Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity(CK), farmer practice(FP), high yield and high efficiency(HH), and super high yield(SH), to estimate the yield gap. Different factorial experiments(fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha~(–1), respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors(contribution rates) were plant density(13.29%)fertilizer(11.95%)hybrids(8.19%)irrigation(4%) for FP to HH, and hybrids(8.94%)plant density(4.84%)fertilizer(1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.     

Whistle signal variations among three Indo-Pacific humpback dolphin populations in the South China Sea: a combined effect of the Qiongzhou Strait's geographical barrier function and local ambient noise?

Geographic variations in the dolphin whistles could be useful in assessing association and isolation among populations. Whistle of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) among the Pearl River Estuary (PRE), Leizhou Bei (LZB) and Sanniang Bay (SNB) populations were investigated. A total of 2850 whistles with legible fundamental contour were extracted and 15 acoustic parameters were measured. Contrary to SNB, PRE and LZB had the same relative proportion of tonal type compositions with flat and sine representing the most frequent types. The generalized linear model analysis showed significant acoustic difference among populations and tonal types. All frequency parameters in SNB were significantly higher than those in PRE and LZB, where no significant variation was observed in most of the parameters either at the population level or within each tonal type. Canonical discriminant functions analysis showed a smaller difference between PRE and LZB than between PRE and SNB and between LZB and SNB. Compared with previous recordings, recent recordings demonstrated a consistent pattern of becoming higher in whistle frequency parameters in both LZB and SNB populations, suggesting that noise pollution in LZB and SNB increasing with time according to the acoustic niche hypothesis. Dolphin whistle's geographic variations could be shaped by the combined function of the geographical barrier function of the Qiongzhou strait and local ambient noise. Considering the isolated condition and the relatively smaller population size of the humpback dolphin in the SNB, more effective and proactive conservation actions should be taken to prevent the extinction of small populations.     

Molecular prevalence,risk factors assessment and haemato-biochemical alterations in hepatozoonosis in dogs from Punjab,India

Hepatozoonosis caused by Hepatozoon canis is an important tick-borne disease of dogs in tropical and sub-tropical regions throughout the world. In the present study evaluation of blood samples collected from 225 dogs presented at Small Animal Clinics, GADVASU, Ludhiana, Punjab (India) was done for the presence of H. canis by PCR based assay targeting a portion of 18S rRNA gene. Of the total samples subjected to PCR, an amplicon of 666 bp was detected in 13.78% samples whereas, routine blood smear examination revealed gamonts in 5.78% samples. Furthermore, prevalence of H. canis infection was found to be significantly associated with season, being highest in summer and lowest in winter while other risk factors e.g. age, sex and breed showed non-significant association. In terms of various clinico-pathological parameters, significant drop in haemoglobin, total red blood cell count, packed cell volume and lymphocytes were recorded in positive cases whereas the total white blood cell count was non-significantly increased. The haematological alterations in the positive cases were lymphopenia, anaemia, thrombocytopenia, relative neutrophilia, neutrophilic leucocytosis, eosinophilia, monocytosis and lymphocytosis while the biochemical profile revealed hypoproteinemia and increased levels of blood urea nitrogen and creatinine (in positive cases) pointing towards renal failure.     

大豆菌核病鉴定方法研究进展

大豆菌核病在全球范围内均有发生,由于病原菌寄主范围较广,难于防治,对大豆产量和品质产生严重影响。对于大豆菌核病抗性种质资源的鉴定是抗性机理研究、基因定位及抗病育种工作的重要基础,文章对大豆菌核病资源鉴定中涉及的接种体(菌丝、孢子和菌核)的培养、植株不同部位的接种鉴定、草酸鉴定、茎中可溶性色素水平测定及田间鉴定方法进行了系统的总结和分析,并针对接种体的选择、环境条件对发病的影响及田间与温室鉴定结果不一致等问题展开讨论,为大豆菌核病抗性资源的筛选,菌核病发病机理及抗性基因的定位研究奠定基础。     

富硒区茶树鲜叶中硒累积与土壤因子的相关性分析

茶树是富硒植物,饮用富硒茶是一种安全、有效的补硒途径之一。茶叶的硒含量受多种环境因素影响,但有关富硒茶区茶树硒积累特性及主要影响因子的研究还鲜有报道。以高硒茶区湖北恩施、陕西安康不同地点生产茶园成龄茶树和根际土壤为研究对象,结合土壤及植物样品全硒含量等多种指标,明确了根际土壤硒含量对茶树硒分布特性的影响,分析了富硒区土壤pH、硒含量等9个重要土壤特性相关因子的数值分布规律。通过对186组具有代表性的土壤样品和附生茶树新梢组织检测数据进行分组和整体相关性分析,证实了富硒区茶叶全硒含量与土壤硒含量之间存在极显著相关（相关系数r=0.59,P<0.01）,揭示了茶叶全硒含量与土壤有机质含量、水解性氮、锌含量以及茶叶中硫、锌含量的显著相关,同时对安康和恩施地区的土壤和茶叶硒含量相关因素进行了深入分析。提出了茶叶硒含量对土壤有机质含量、硫含量、硒含量和锌含量的数学模型,模型拟合优度为0.512 6,达极显著水平（P<0.01）。     

入侵性食叶害虫椰子织蛾的单倍型多样性分析

【目的】分析危害棕榈科Palmae植物的一种重要入侵食叶害虫椰子织蛾Opisina arenosella单倍型在原产地和入侵地的分布特点,揭示椰子织蛾入侵我国的虫源信息。【方法】利用线粒体COI基因分析16个地理种群共计172个样本,比较椰子织蛾印度种群和入侵地(中国、马来西亚和泰国)种群的遗传关系。【结果】片段长度为625 bp的172条序列共鉴定出12个单倍型,包含15个变异位点,构成2个明显的单倍型分支,其中一个分支由11个单倍型(IN1～IN11)组成,均来自印度种群,单倍型IN1是6个印度种群的共享单倍型,IN2～IN11为独享单倍型;另一个分支为单倍型HAP,由来自中国、马来西亚和泰国的种群共享;HAP与11个来自印度的单倍型IN1～IN11均存在4个变异位点。【结论】入侵地区的椰子织蛾种群来自同一基因型或者具有相同的入侵源;椰子织蛾种群入侵后受环境选择压力,在新栖息地产生新的突变或杂交。     

铁皮石斛PRC2复合体成员的鉴定及对胁迫响应的表达分析

为了探讨PRC2复合体在铁皮石斛生长发育和胁迫响应中的功能,通过生物信息学方法筛选了铁皮石斛PRC2核心成员DcCLF、DcSWN、DcEMF2、DcFIE和DcMSI1,借助酵母双杂交技术分析了它们之间的互作关系,利用半定量PCR分析了PRC2核心成员的组织表达谱,通过荧光定量PCR检测了它们对非生物胁迫(低温、高温、脱水)和病害胁迫(齐整小核菌、灰葡萄孢霉菌)的响应情况。结果表明,铁皮石斛PRC2复合体包含5个成员:E(z)同源基因DcCLF和DcSWN、Su(z)12基因DcEMF2、ESC基因DcFIE、p55基因DcMSI1,且这5个成员间的互作关系基本符合模式植物的互作模式,也存在物种特异性,表明PRC2复合体在进化中既有保守性也有特殊性。PRC2核心成员在铁皮石斛根、茎、叶、花蕾、成花中均有表达,但不同基因的表达存在组织差异性。同时,PRC2成员响应不同的环境和病害胁迫:DcCLF受低温、高温和脱水等各种环境胁迫的显著诱导;DcMSI1和DcEMF2在齐整小核菌侵染下表达明显上调,而DcSWN在灰葡萄孢霉菌侵染下受诱导程度最大。铁皮石斛PRC2复合体在生长发育和胁迫应答中发挥重要作用,可为分子辅助育种提供关键靶标基因。     

播期对川中丘陵区油菜倒伏性状的影响

油菜机械化生产中,植株倒伏是影响机械化收获的重要因素。为探讨不同播种期对川中丘陵区油菜倒伏性状的影响,以川油36和蓉油18为供试材料,分别设置9月22日、9月29日、10月6日、10月13日和10月20日5个播期处理,分析不同播期条件下油菜生育期气象因子、倒伏性状指标的变化情况。结果表明,随播种期推迟,油菜生育期内的降水量、积温、日均最高气温、日均最低气温和日照时长均逐渐下降,生育期逐渐缩短,成熟期植株株高、分枝部位、根颈粗、茎秆粗降低,倒伏系数增加。油菜抗倒伏能力在9月22-29日播期处理之间最强。因此,川中丘陵区油菜的适宜播期为9月下旬。     

Serological survey of Toxoplasma gondii in captive nonhuman primates in zoos in Spain

Toxoplasma gondii is a widely distributed zoonotic protozoan parasite, which can affect most warm-blooded species. Some species of non-human primates (NHPs) are highly susceptible to T. gondii infection. The aim of the study was to determine the seroprevalence and risk factors associated with T. gondii infection in NHPs housed in zoos in Spain. Sera from 189 NHPs belonging to 33 species were collected in eight zoos. Additionally, 10 of the 189 animals were longitudinally sampled. Anti-T. gondii antibodies were detected in 48 NHPs (25.4%; confidence interval of 95% (CI_95%): 19.2–31.6) using a modified agglutination test (MAT; cut-off = 25). Seropositive animals had titers of 25 (6.3%), 50 (8.3%), 100 (8.3%) and ≥500 (68.8%). Seropositivity was detected in 15 of the 33 species (45.5%). Of the 10 NHPs sampled more than once, two animals (one Barbary macaque [Macaca sylvanus] and one common chimpanzee [Pan toglodytes]) seroconverted along the study period, while one seropositive chimpanzee increased antibody titers over time. The Hominidae family (OR = 5.9; CI_95%: 2.7–12.8) and sex (females) (OR = 2.1; CI_95%: 1.1–4.1) were risk factors potentially associated with seropositivity to T. gondii. Our results evince a widespread circulation of T. gondii in NHPs in zoos in Spain, which may be of conservation concern. Control measures should be implemented to minimize the risk of exposure of these species to T. gondii.