黑胫病菌（Leptosphaeria biglobosa）在油菜叶片和茎中的侵染过程观察     

史志丹  宋培玲  郝丽芬  皇甫海燕  燕孟娇  杨永青  吴晶  赵丽丽  李子钦 《中国油料作物学报》2021,43(2):286-292

为明确黑胫病菌（Leptosphaeria biglobosa）在甘蓝型油菜叶片和茎中的侵染及扩展过程，利用绿色荧光蛋 白（GFP）标记的黑胫病菌株接菌油菜叶片，利用激光共聚焦显微镜观察菌株在油菜叶片和茎中的侵染过程。结果 表明，接种油菜叶片7 h后，分生孢子萌发并长出芽管；17 h后，芽管侵入气孔；24 h后，分生孢子全部萌发；36 h后萌 发的芽管形成菌丝；120 h后，菌丝在叶片表皮细胞间隙蔓延，并侵入叶肉细胞。13 d后，菌丝侵入茎部皮层组织； 15 d后，菌丝在皮层细胞间隙蔓延，并侵染至茎表皮；21 d后，菌丝侵染至维管组织；23 d后，菌丝侵染至茎韧皮部； 25 d后，茎导管被侵染，并向木质部扩展。本研究发现的L. biglobosa 在油菜叶片和茎中的侵染过程，可为油菜与黑 胫病菌互作的研究、黑胫病致病机理及防治提供参考。  相似文献   

Screening and identification of soybean varieties with high phosphorus efficiency at seedling stage     

Hui Wang  Ahui Yang  Guang Yang  Hongyu Zhao  Futi Xie  Huijun Zhang  Haiying Wang  Xue Ao 《中国油料作物学报(英文)》2021,6(1):41-49

In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X₁),relative value of root P utilization efficiency(X₂),and root volume(X₃)under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X₁t 0.320X₂t 0.007X₃-0.664(P=0.000,R²=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.  相似文献   

农村互联网发展对中国玉米全要素生产率的影响     

王博  张永强  宫思羽  董权瑶  付小钊 《浙江农业学报》2021,33(12):2435

采用DEA-mamlquist指数测算2004—2019年中国17个玉米主产省(区)的全要素生产率,运用联立方程组模型实证检验农村互联网发展对玉米全要素生产率的影响及其作用机理,并分区域探讨其差异性。结果显示:2004—2019年中国玉米全要素生产率年均增长0.2%,主要依靠技术进步的单轨模式驱动。农村互联网的发展显著(P<0.01)提升玉米全要素生产率,主要依靠技术进步和技术效率的协同作用驱动。分区域来看,农村互联网发展对玉米全要素生产率均具有显著(P<0.01)的促进作用,其影响程度由高到低依次为北方春播玉米区>黄淮海平原夏播玉米区>西北灌溉玉米区>西南山地玉米区。建议进一步提高农村互联网的配套设施建设,发挥互联网“连接经济”的优势,应用多元化互联网技术,促进不同生态类型区玉米生产效率的提升。  相似文献   

小球藻遗传转化技术研究进展     

曹苏珊  薛静  王倩楠  张秀海  安贤惠 《水产科学》2021,(2):294-300

小球藻( Chlorella )是一种单细胞真核藻类,属绿藻门、绿藻纲、绿球藻目、小球藻科、小球藻属 [1] 。作为最早开发的真核微藻之一,具有高营养价值、生长快速、结构简单、易工业化集成等显著优点。其细胞形态为球形或椭圆形,直径3~12 μm,呈单生或聚集成群状生长 [2] ,分布广泛,多见于淡水、咸水和土壤中。作为地球上最早的生命之一,小球藻基因比较稳定,至今未见有关其基因自发突变的报道。因其富含蛋白质、脂质、维生素、活性代谢产物等多种营养物质而被公认为具有高附加值和医疗保健作用,已经被广泛应用于保健食品 [3] 、水产养殖 [4] 、生物能源 [5] 等方面,关于小球藻生物技术的研究主要集中在基因组学 [6] 、分子遗传学 [7] 、代谢机理 [8] 、大规模培养 [9] 等方向。  相似文献   

Screening for Small Molecule Inhibitors of BMP-Induced Osteoblastic Differentiation from Indonesian Marine Invertebrates     

Hiroyuki Yamazaki  Satoshi Ohte  Henki Rotinsulu  Defny S. Wewengkang  Deiske A. Sumilat  Delfly B. Abdjul  Wilmar Maarisit  Magie M. Kapojos  Michio Namikoshi  Takenobu Katagiri  Hiroshi Tomoda  Ryuji Uchida 《Marine drugs》2020,18(12)

  相似文献   

稻曲病菌交配型基因MAT1-2-1和MAT1-2-8的特性分析     

雍明丽  于俊杰  曹慧娟  俞咪娜  潘夏艳  宋天巧  刘永锋 《植物病理学报》2021,51(1):19-29

 有性生殖在真菌的生活史和进化过程中具有重要作用,而交配型基因是控制有性生殖的关键因子。前期研究发现稻曲病菌(Villosiclava virens)MAT1-2型菌株中包含MAT1-2-1和MAT1-2-8两个交配型基因,但是它们如何调控稻曲病菌有性生殖依然不清楚。本文研究了它们在不同侵染和生长发育时期的表达模式和编码的蛋白结构特性。研究表明MAT1-2-1在侵染不同阶段一直下调表达;而MAT1-2-8在侵染早期(5 dpi)上调表达,在侵染后期下调表达。与营养菌丝阶段比较,MAT1-2-1和MAT1-2-8在有性发育过程菌核形成、菌核萌发、子座原基形成和子座成熟4个阶段的表达量都是下降的,在菌核形成阶段表达量最低。生物信息学分析显示MAT1-2-1和MAT1-2-8具有磷酸化位点,为非分泌蛋白,无明显的跨膜结构域。蛋白同源比对分析表明MAT1-2-1与香柱菌(Epichloë typhina)的MAT1-2-1同源性最高,而MAT1-2-8与绿僵菌(Metarhizium)的MBR_08192蛋白同源性最高。进一步研究发现MAT1-2-1和MAT1-2-8能够互作,并分别主要定位在细胞核和细胞基质中。通过质谱技术鉴定到MAT1-2-1的一些候选互作蛋白,如假定Ran交换因子Prp20/Pim1(KDB12229.1)、假定rRNA处理蛋白Ebp2(KDB12923.1)及组蛋白H1(KDB12711.1)等。因此,以上结果为研究稻曲病菌交配型基因MAT1-2-1和MAT1-2-8调控有性生殖的生物学功能奠定了基础。  相似文献   

父母本不同行距配置对昆虫授粉效率的影响     

张伟龙  张伟  徐长洪  王鹏年  赵丽梅  吴兴宏  丁孝羊 《大豆科学》2017,36(5)

为探讨昆虫为杂交大豆授粉的行为,提高授粉效率,以大豆细胞质雄性不育系JLCMS34A和保持系JLCMS34B为材料,研究父母本3种行距配置(T1、T2、T3)对昆虫授粉行为及产量构成的影响。结果表明:行距配置T2条件下昆虫授粉效率最高,母本单株粒数最多,为45.98个(2011年),与T1、T3差异达到显著水平,T3配置授粉效率最差,单株粒数最少,为32.06个(2012年),与T1、T2差异达到极显著水平。在吉林省洮南地区适当缩小父母本行距,增加母本间行距可有效促进昆虫授粉效率,提高结实率。  相似文献   

Calibration and validation of optical chlorophyll‐measuring devices for use in predicting crude protein concentration in tropical grass herbage          下载免费PDF全文

M. P. Hughes  C. H. O. Lallo  V. Mlambo  P. G. A. Jennings 《Grass and Forage Science》2017,72(1):118-136

The objective of this experiment was to evaluate the Fieldscout CM 1000 NDVI and Yara N‐Tester as easy‐to‐use and cost‐effective tools for predicting foliar chlorophylls (a, b and total) and crude protein (CP) concentrations in herbage from three tropical grass species. Optical chlorophyll measurements were taken at three stages (4, 8 and 12 weeks) of regrowth maturity in Guinea grass (Panicum maximum) and Mulato II (Brachiaria hybrid) and at 6 and 12 weeks maturity in Paspalum spp (Paspalum atratum). Grass samples were harvested subsequent to optical measurements for laboratory analysis to determine CP and solvent‐extractable chlorophylls (a, b and total) concentrations. Optical chlorophyll measurements and CP concentrations were highly correlated (Yara N‐Tester: r² = 0·77–0·89; Fieldscout CM 1000 NDVI: r² = 0·52–0·84). Crude protein prediction models from the Yara N‐Tester and Fieldscout CM 1000 NDVI accounted for 70–89% and 44–73% CP variability, respectively, in Mulato II and Guinea grass. The Yara N‐tester produced more accurate and reliable CP estimates based on very high concordance correlation coefficient [CCC (0·73–0·91)] and low rMSPE, mean and regression bias. It is concluded that the Yara N‐Tester produces more accurate and reliable CP estimates of tropical pastures.  相似文献   

Comparative effect of advanced soy products or corn protein concentrate with porcine meal on growth,body composition,and distal intestine histology of Florida pompano,Trachinotus carolinus     

Romi Novriadi  Elizabeth Spangler  D. Allen Davis 《Journal of the World Aquaculture Society》2019,50(2):433-447

The present study was designed to investigate the effects of diets containing advanced soy products (enzyme‐treated soy and fermented soy) or corn protein concentrate (CPC) in combination with porcine meal (PM) to completely replace poultry byproduct meal (PBM) on growth performance, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus. Four experimental diets were formulated to be isonitrogenous and isolipidic, to contain 400 g/kg crude protein and 80 g/kg lipid. A reference diet (PBM diet [PBMD]) contained 150 g/kg PBM and 495 g/kg soybean meal (SBM), and three test diets were formulated replacing PBM with 15 g/kg of CPC (CPC diet [CPCD]) or replacing all SBM and PBM with 535 g/kg fermented soy (fermented soybean meal diet [FSBMD]) or 451.3 g/kg enzyme‐treated soy (enzyme‐treated soybean meal diet [ESBMD]). All three test diets were supplemented with 38 g/kg of PM. Diets were fed based on a percentage of bodyweight adjusted after sampling the fish every 2 weeks to triplicate groups of Florida pompano juveniles (mean weight 8.06 ± 0.22 g). After 8 weeks of feeding, fish fed CPCD and ESBMD performed equally well in terms of final body weight, thermal growth coefficient, and percentage weight gain in comparison to fish fed PBMD. In all cases, feeding FSBMD resulted in poor feed conversion and lower feed intake compared to other treatments. Protein retention efficiency, whole‐body proximate composition, phosphorus, sulfur, potassium, magnesium, calcium, sodium, and zinc contents were not significantly influenced by the dietary treatments. The results obtained in the present histological study showed no significant differences in the thickness of serous layer, muscular layer, and submucosal layer of the intestine among treatments. Fish fed CPCD showed a significant widening of the lamina propria with an increase of cellular infiltration and higher presence of goblet cells compared to other dietary treatment. Based on these results, 451 g/kg ESBM or combination of 150 g/kg of CPC and 495 g/kg SBM supplemented with 38 g/kg PM can be utilized to develop a practical diet for juvenile Florida pompano without impacting growth, nutritive parameters, and several distal intestine health parameters.  相似文献   

Carbohydrate and crude protein fractions in perennial ryegrass as affected by defoliation frequency and nitrogen application rate          下载免费PDF全文

P. A. Loaiza  O. Balocchi  A. Bertrand 《Grass and Forage Science》2017,72(3):556-567

The objective of this study was to evaluate the effects of defoliation frequency (either at two‐ or three‐leaf stage) and nitrogen (N) application rate (0, 75, 150, 300, 450 kg N ha^?1 year^?1) on herbage carbohydrate and crude protein (CP) fractions, and the water‐soluble carbohydrate‐to‐protein ratio (WSC:CP) in perennial ryegrass swards. Crude protein fractions were analysed according to the Cornell carbohydrate and protein system. Carbohydrate fractions were analysed by ultra‐high‐performance liquid chromatography. Sward defoliation at two‐leaf stage increased the total CP, reduced the buffer‐soluble CP fractions and decreased carbohydrate fractions of herbage (P < 0·001). The effect of defoliation frequency was less marked during early spring and autumn (P < 0·001) than for the rest of the seasons. An increase in N application rate was negatively associated with WSC, fructans and neutral detergent fibre (P < 0·001), and positively associated with CP and nitrate (N‐NO₃) contents of herbage. Nitrogen application rate did not affect CP fractions of herbage (P > 0·05). The fluctuations in CP and WSC contents of herbage resulted in lower WSC:CP ratios during early spring and autumn (0·45:1 and 0·75:1 respectively) than in late spring (1·11:1). The herbage WSC:CP ratio was greater (P < 0·001) at the three‐leaf than the two‐leaf defoliation stage and declined as the N application increased in all seasons (P < 0·001). The results of this study indicate that CP and carbohydrate fractions of herbage can be manipulated by sward defoliation frequency and N application rate. The magnitude of these effects, however, may vary with the season.  相似文献