武威绿洲日光温室葡萄主要病害发生规律及综合防治

调查总结了武威绿洲日光温室葡萄主要病害霜霉病、白粉病、白腐病的发生规律,并在实践的基础上提出了不同病害的防治适期和防治关键技术.     

观赏棕榈银海枣的研究进展

银海枣树形独特,景观效果佳,是值得推广的优良城市园林绿化树种.文章综述了银海枣的引种、耐寒机理研究、栽培技术、病虫害防治以及园林绿化应用研究进展,对其研究应用前景作了展望,并对生产应用存在的问题提出了相关建议.     

抗病性不同大豆品种根面及根际微生物区系的变化 Ⅱ.连作大豆(重茬)根面及根际微生物区系的变化

采用平板计数法测定了两个抗根腐病连作大豆品种生育期间根面和根际微生物区系动态变化。结果表明,两个品种大豆根面细菌随生育期增加呈递减趋势,品种间无差异。合丰25(H25)的根际细菌数量随生育期呈递减趋势,绥农10号(S10)根际细菌数量从三叶期到鼓粒初期不断增加,到成熟期又急剧减少。感病品种H25根瘤重明显低于抗病品种S10。H25根面真菌和镰孢霉总数在三叶期和成熟期均高于S10,苗期是根腐病的主要发病期。总之,在连作条件下,无论抗病品种还是感病品种大豆成熟期其根面和根际细菌减少,真菌和主要病原菌(镰孢霉Fusarium)都会大量富集,表明根系分泌物对根面和根际的微生物种群有选择性地促进或抑制作用。     

抗病性不同大豆品种根面及根际微生物区系的变化 Ⅰ.非连作大豆(正茬)根面及根际微生物区系的变化

采用平板计数法测定了3个抗病性不同的大豆品种在生育期内根面和根际微生物区系的变化情况,并应用荧光计数法直接测定了根际细菌和真菌的生物量。结果表明,土体的微生物种类最丰富、根际的次之、根面的较单一。播种后从三叶期到鼓粒初期,根面和根际的可培养细菌总数随生育期逐渐增加,鼓粒初期达最大值,而成熟期则有明显的下降;大豆根际细菌生物量也存在相同的变化规律。抗病性不同的大豆品种其根面、根际可培养细菌总数存在差异;抗病品种大豆的根瘤重明显高于感病品种。种植一季后感病品种根际积累的病原生物(镰孢霉Fusarium.sp.和大豆胞囊线虫Heterodera.glycines的胞囊数)明显高于抗病品种。说明大豆根系分泌物对微生物具有选择性的促进或抑制作用,不同大豆品种以及同一大豆品种在不同生育时期根系分泌物的组成和数量不同,从而使大豆根面及根际形成了特定的微生物区系组成。     

Assessment of genetic diversity among African cassava Manihot esculenta Grantz accessions resistant to the cassava mosaic virus disease using SSR markers

A study was conducted to determine the extent of genetic diversity among African cassava (Manihot esculenta Crantz) accessions resistant to the cassava mosaic virus disease (CMD), using simple sequence repeat (SSR) markers. The accessions included a breeding stock (clone 58308), five improved lines, 62 CMD resistant and 10 CMD susceptible landraces. Genetic diversity was assessed among accessions in five cluster groups derived from UPGMA analysis on data from 18 SSR primer pairs. Average gene diversity, He, was high in all cluster groups, with an average heterozygosity of 0.591 ± 0.061. The estimator of inbreeding Fis revealed a low level of inbreeding within groups and averaged −0.262 ± 0.142. Gene diversity among all accessions was 51.4% and gene diversity within cluster groups was 46.6%, while 4.8% was due to diversity between the different cluster groups. The amount of genetic differentiation measured by Gst and Fst were 9.6% and 12.1% respectively, indicating a weak genetic structure.     

我国奶牛养殖小区生产工艺与工程配套技术体系研究

近年来，中国奶业持续快速发展，作为我国奶牛饲养主体的农村散户小规模饲养已占奶牛总饲养量的80%左右。由于养殖规模小，设备简陋，饲养条件差，疾病难以防控，很多地方试图通过建设奶牛养殖小区来加以解决。但目前我国奶牛养殖小区还没有一套可供实际推广应用的生产工艺模式，小区没有科学的规划布局，工艺技术路线和工程防疫技术不到位，设施设备的配置不合理，饲养方式不统一，管理松散，缺乏计划性和全年生产的均衡一致性，无法从根本上克服这些矛盾。为此，作者在广泛调研的基础上，结合中国国情，提出了一套适合于奶牛养殖小区的舍饲散养生产工艺模式，并就该工艺模式的特点、生产工艺技术路线、工艺技术参数确定、配套设施与设备、小区布局以及工程防疫等关键技术进行了探讨，旨在为推进奶牛养殖小区的规模化、标准化的进程，提升我国奶业生产水平提供参考。     

Soil fumigation and compost amendment alter soil microbial community composition but do not improve tree growth or yield in an apple replant site

Apple replant disease (ARD) is a disease complex that reduces survival, growth and yield of replanted trees, and is often encountered in establishing new orchards on old sites. Methyl bromide (MB) has been the fumigant used most widely to control ARD, but alternatives to MB and cultural methods of control are needed. In this experiment, we evaluated the response of soil microbial communities and tree growth and yield to three pre-plant soil treatments (compost amendment, soil treatment with a broad-spectrum fumigant, and untreated controls), and use of five clonal rootstock genotypes (M.7, M.26, CG.6210, G.30 and G.16), in an apple replant site in Ithaca, New York. Polymerase chain reaction (PCR)—denaturing gradient gel electrophoresis (DGGE) analysis was used to assess changes in the community composition of bacteria and fungi in the bulk soil 8, 10, 18 and 22 months after trees were replanted. PCR-DGGE was also used to compare the community composition of bacteria, fungi and pseudomonads in untreated rhizosphere soil of the five rootstock genotypes 31 months after planting. Tree caliper and extension growth were measured annually in November from 2002 to 2004. Apple yield data were recorded in 2004, the first fruiting year after planting. Trees on CG.6210 rootstocks had the most growth and highest yield, while trees on M.26 rootstocks had the least growth and lowest yield. Tree growth and yield were not affected by pre-plant soil treatment except for lateral extension growth, which was longer in trees growing in compost-treated soil in 2003 as compared to those in the fumigation treatment. Bulk soil bacterial PCR-DGGE fingerprints differed strongly among the different soil treatments 1 year after their application, with the fingerprints derived from each pre-plant soil treatment clustering separately in a hierarchical cluster analysis. However, the differences in bacterial communities between the soil treatments diminished during the second year after planting. Soil fungal communities converged more rapidly than bacterial communities, with no discernable pattern related to pre-plant soil treatments 10 months after replanting. Changes in bulk soil bacterial and fungal communities in response to soil treatments had no obvious correlation with tree performance. On the other hand, rootstock genotypes modified their rhizosphere environments which differed significantly in their bacterial, pseudomonad, fungal and oomycete communities. Cluster analysis of PCR-DGGE fingerprints of fungal and pseudomonad rhizosphere community DNA revealed two distinct clusters. For both analyses, soil sampled from the rhizosphere of the two higher yielding rootstock genotypes clustered together, while the lower yielding rootstock genotypes also clustered together. These results suggest that the fungal and pseudomonad communities that have developed in the rhizosphere of the different rootstock genotypes may be one factor influencing tree growth and yield at this apple replant site.     

谈园林植物病虫害防治

随着社会经济的发展,园林绿化工作取得了前所未有的成绩,园林植物的生态效益、经济效益、观赏效益日益凸现。与此同时,园林植物病虫害的发生也出现了复杂化、危险化的趋势,对绿地和风景区危害较大。病虫害常常导致园林植物生长衰弱和死亡,影响植物的生长、发育、繁殖及其观赏价值,甚至引起整株死亡,使绿化树种、风景林等林木大片衰败或死亡,从而造成重大的经济损失。在园林生态里,由于人类、植物、有害生物、环境条件和天敌等各组分之间存在着相当复杂的关系,所以其中任何一因子的变动,都会直接或间接地影响整个的城市园林生态系统。那么,在防治上要从生态学观点出发,在管理上创造不利于病虫害发生的条件,减少或不用化学农药,保护天敌,提高自然的控制能力,保持园林生态的稳定和可持续性发展。     

玉米抗粗缩病自交系种质的发掘和遗传多样性及其在育种中的应用

玉米粗缩病是近十年来危害我国部分玉米产区的主要病害之一, 挖掘抗粗缩病玉米种质, 进而培育抗病品种是防治粗缩病危害最经济有效的途径。选用184份常用玉米自交系(包括111份普通玉米和73份糯玉米)于2009—2010年在玉米粗缩病重发区江苏沿江地区农业科学研究所试验田进行田间自然鉴定; 同时利用117对SSR引物对供试的玉米自交系进行多态性检测, 按UPGMA方法, 利用Powermarker 3.0软件对184份自交系进行系统聚类分析。筛选出2份高抗(T877和YJ7)、6份抗病普通自交系和2份糯玉米抗性种质。基于644个SSR多态性位点, 结合系谱资料和育种实践, 将184份自交系划为9个杂种优势亚群。自交系4S及其衍生系(第VI亚群)和来源于美国杂交种78599的玉米自交系(第VIII亚群)为玉米抗粗缩病育种的重要种质。