澳洲坚果叶斑病新病原及生物学特性

摘 要：在澳洲坚果园进行病样采集时,发现一种叶部病害,为明确该病害的病原菌种类,将采集的病叶进行分离,并运用科赫法则测定致病性,根据病原菌的形态学特征和rDNA-ITS序列分析对病原菌进行鉴定。结果表明,分离菌株的菌落形态和分生孢子形态都与小孢拟盘多毛孢（Pestalotiopsis microspora）一致,经分子生物学鉴定,其ITS序列与小孢拟盘多毛孢的ITS序列的同源性为99%,将引起澳洲坚果叶斑病的病原菌鉴定为小孢拟盘多毛孢。生物学特性结果表明：PDA培养基最有利于病原菌生长,培养3天后,菌落直径达62.9 mm,最佳碳源为葡萄糖,最佳氮源为硫酸铵,病原菌在15-30 ℃均能生长,最适生长温度为28℃,病原菌在pH为4-11范围内均可生长,pH为7时生长最佳,全光照有利于病原菌生长。本文首次报道Pestalotiopsis microspora引起澳洲坚果叶斑病。     

代乳粉对羔羊生产性能及血液生化指标的影响

本文旨在研究代乳粉对羔羊生产性能和血液生化指标的影响,并优选出适宜的羔羊代乳粉营养水平和稀释比例。选择80只健康的小尾寒羊羔羊,采用单因子试验设计,将羔羊随机分为4组进行试验。初生羔羊吃足初乳,于5天后分组,采用逐渐替代法,将母乳转换成3种不同营养水平的代乳粉,分别以一定的稀释比例哺喂3组羔羊,另1组为对照组(喂纯羊乳)。结果表明:①饲喂代乳粉对各组羔羊的死亡率无显著影响。②试验1组的平均日增重(ADG)为193 g,明显高于对照组的151.25 g和试验3组的107 g,差异显著(P<0.05);而试验2组的平均日增重为160.5 g,与其他3组无明显差异(P>0.05)。③血液指标中,血糖(Glu)值以试验1组最高,为3.84 mmol/L,明显高于对照组和其他2组(P<0.01);试验2组的血清尿素氮(BUN)值为16.89 mg/dL,极显著地高于对照组的9.99 mg/dL和试验3组的8.76 mg/dL(P<0.01),显著高于试验1组(P<0.05);各组中血清白蛋白(ALB)含量比较接近,无显著差异(P>0.05);总蛋白(TP)含量试验1组最高为52.26 g/L,极显著高于对照组和试验3组(P<0.01),而与试验2组相比差异不显著(P>0.05)。早期断奶羔羊平均每只每日进食的消化能和粗蛋白分别为9.21 MJ、106.92 g,哺喂营养含量和稀释比例适宜的代乳粉(试验1组)能促进早期断奶羔羊的生长发育。     

欧洲花楸引种及生物学特性

为了丰富北方寒冷地区珍贵园林绿化树种资源,于1986年从波兰引进欧洲花楸种子,进行了播种繁殖,对其植物学特性、生物学特性、生长节律等进行了系统研究。结果表明:欧洲花楸生长迅速,生长高峰期出现在7月中下旬,全年生长期为120d左右。3年生实生苗进入快速生长期,年平均生长量达146.3cm;5年生实生苗即可开花结果。该树种适宜在东北地区推广栽培。     

立地条件对长白落叶松养分生物学特性的影响

以黑龙江省佳木斯市孟家岗林场立地指数为11(差)、13(中)和17(好)的长白落叶松人工幼林作为研究对象,以氮、磷、钾为例,对其根(粗根边材、粗根心材、中根、小根)、树干(边材、心材)、枝(新鲜树枝、立枯枝)、树皮(新鲜树皮、死树皮)和针叶进行了养分生物学特性的研究。结果表明:小根(l≤2cm)、活枝、针叶中氮的质量分数,以及粗根(l≥5cm)、树干边材、针叶中磷的质量分数,和活树皮中钾的质量分数在3种立地条件下的林木之间,分别表现出显著的差异;其他器官中氮、磷、钾的质量分数在3种立地条件下的林木之间无显著差异;树干边材中氮、磷、钾的质量分数均显著高于树干心材,而粗根心材和粗根边材中氮、磷、钾的质量分数方面无显著差异;新鲜树枝和新鲜树皮中氮、磷、钾的质量分数均显著高于相应的立枯枝和死树皮;小根中氮、磷、钾的质量分数显著高于中根(2相似文献   

配方施肥改善米老排容器苗生长指标

为筛选米老排容器苗最佳施肥组合,采用L₁₆ (4 ⁵)正交试验设计和等量施肥法,研究N、P和K肥3因素对米老排容器苗苗高、地径、生物量以及养分利用的影响。研究结果表明：不同施肥组合处理对米老排容器苗苗高、地径、总生物量等指标均有着显著影响,配方施肥对米老排容器苗的生长发育具有明显促进作用;3种肥料对米老排容器苗苗高生长的影响效应均是N>P>K,其施肥最优组合是N₁P₃K₂（每株施N、P和K分别为50、50、60 mg）,对地径生长和生物量积累影响效应均为N>K>P,施肥最优组合分别是N₁P₄K₂（每株施N、P和K分别为50、60、60 mg）和N₁P₄K₁（每株施N、P和K分别为50、60、45 mg）;合理的配方施肥能有效提高米老排苗木的养分利用效率。综合苗木各指标看,米老排容器苗最优施肥配方是：N₁P₄K₁（每株施N、P和K分别为50、60、45 mg）。     

Relay-intercropping soybean with maize maintains soil fertility and increases nitrogen recovery efficiency by reducing nitrogen input

Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.     

Deep neural network algorithm for estimating maize biomass based on simulated Sentinel 2A vegetation indices and leaf area index

Accurate estimation of biomass is necessary for evaluating crop growth and predicting crop yield.Biomass is also a key trait in increasing grain yield by crop breeding.The aims of this study were(i)to identify the best vegetation indices for estimating maize biomass,(ii)to investigate the relationship between biomass and leaf area index(LAI)at several growth stages,and(iii)to evaluate a biomass model using measured vegetation indices or simulated vegetation indices of Sentinel 2A and LAI using a deep neural network(DNN)algorithm.The results showed that biomass was associated with all vegetation indices.The three-band water index(TBWI)was the best vegetation index for estimating biomass and the corresponding R2,RMSE,and RRMSE were 0.76,2.84 t ha−1,and 38.22%respectively.LAI was highly correlated with biomass(R2=0.89,RMSE=2.27 t ha−1,and RRMSE=30.55%).Estimated biomass based on 15 hyperspectral vegetation indices was in a high agreement with measured biomass using the DNN algorithm(R2=0.83,RMSE=1.96 t ha−1,and RRMSE=26.43%).Biomass estimation accuracy was further increased when LAI was combined with the 15 vegetation indices(R2=0.91,RMSE=1.49 t ha−1,and RRMSE=20.05%).Relationships between the hyperspectral vegetation indices and biomass differed from relationships between simulated Sentinel 2A vegetation indices and biomass.Biomass estimation from the hyperspectral vegetation indices was more accurate than that from the simulated Sentinel 2A vegetation indices(R2=0.87,RMSE=1.84 t ha−1,and RRMSE=24.76%).The DNN algorithm was effective in improving the estimation accuracy of biomass.It provides a guideline for estimating biomass of maize using remote sensing technology and the DNN algorithm in this region.     

‘王林’苹果苦痘病的防治试验

近几年来‘王林’苹果苦痘病的发病率较高,为了探索防治办法,2018—2019年在瓦房店市驼山乡大魏村‘王林’苹果园进行施用“聚能螯合钙+硅”+生物有机肥试验。结果表明:第1年好果率达到90.2%,比对照提高15.0%;第2年分别为96.82%、22.23%。病果的病斑数也明显减少。     

开食料中性洗涤纤维水平对犊牛生长性能、血清生化指标和抗氧化功能的影响

【目的】探究开食料中性洗涤纤维（NDF）含量对犊牛生长发育、血清生化指标及抗氧化性能的影响,为犊牛开食料的合理配制提供试验依据。【方法】选取平均体重为（42±2.5）kg 的60头（包括36头公犊牛,24头母犊牛）新生荷斯坦犊牛,随机分为4个试验组,每组15头（9头公犊牛+6头母犊牛）,15日龄起依次饲喂10%（10N）、15%（15N）、20%（20N）和25%（25N）NDF水平的开食料。试验犊牛单个饲养于犊牛岛,70日龄断奶,饲喂至112 日龄。每日记录开食料采食量,每两周称量犊牛的体重,于35和112日龄测量犊牛的体尺,35、70、90和112日龄空腹颈静脉抽血测定血液生化和抗氧化指标。【结果】（1）70—112日龄,犊牛开食料采食量10N组显著低于25N组（P＜0.5）;42—70日龄,20N和25N组NDF采食量显著高于10N和15N组（P＜0.05）;70—112日龄,NDF采食量随开食料NDF水平升高而显著增加（P＜0.05）; （2）70—112和15—112日龄,15N组犊牛体增重显著高于其他三组（P＜0.05）,分别高出12.67%、43.56%、30.17%和6.16%、18.09%、15.16%;15N组体高显著高于20N和25N组（P＜0.05）,体斜长和胸围显著高于25N组。（3）90日龄,15N组血清球蛋白含量显著高于其他三组,白球比显著低于其他三组（P＜0.05）;112日龄,血清谷丙转氨酶、谷草转氨酶和碱性磷酸酶含量随NDF水平的提高而显著降低（P＜0.05）。（4）35、70和112日龄,15N、20N和25N组血清超氧化物歧化酶浓度显著高于10N（P＜0.05）组,血清丙二醛浓度低于10N组。【结论】犊牛开食料中NDF水平直接影响进食量和体增重,15—112日龄荷斯坦犊牛开食料中NDF的适宜水平为15%。     

广东生物种质资源数据管理网络平台构建

广东生物种质资源数据管理网络平台是集成数据库技术和网络技术构建的基于B/S结构的生物种质资源数据标准化及管理平台，该平台为广东省的生物种质资源收集、评价、利用和研究提供一套运行于局域网和互联网的生物种质资源数据管理与分析系统软件，并已投入到广东省22个种质资源保存、研究单位使用，建立了42个物种种质资源数据库管理系统，对种质资源数据进行统一、规范的管理，实现种质资源数据库共建信息共享。