农机设备电磁兼容设计专家系统

提出了针对农机设备电磁兼容设计的专家系统,分析了系统知识库建立的依据,对有关电磁兼容设计的知识进行了整理,将其分成描述类知识、规则类知识和案例类知识,并对案例类知识的推理算法进行了详细设计。结果表明:建立的电磁兼容设计专家咨询系统能起到部分代替专家指导生产设计实践的作用。     

大白杜鹃与露珠杜鹃杂交亲和性及其杂交果实发育动态研究

以大白杜鹃为母本,露珠杜鹃为父本进行杂交试验,通过测算露珠杜鹃与大白杜鹃的花柱长度比进行杂交可行性分析,利用荧光显微镜观察授粉后露珠杜鹃花粉管的生长状况确定杂交亲和性,并对温室和露天两种条件下的杂交果实的纵横径动态变化情况进行观测。研究结果显示,露珠杜鹃与大白杜鹃的花柱长度比为0.98,推测两种杜鹃杂交容易成功。露珠杜鹃花粉管在授粉后9 d进入大白杜鹃胚珠并完成受精,证实两种杜鹃杂交亲和。温室和露天条件下的杂交果实形态成熟时间均约180 d,其中,授粉后0~9 d为第1次缓慢生长期,授粉后9~105 d为第1次迅速生长期,授粉后105~135 d为第2次缓慢生长期,授粉后135~180 d为第2次迅速生长期;果实纵径和横径的生长动态变化过程相似,但横径的生长动态曲线较纵径平缓。温室条件下的杂交果实纵横径大小明显高于露天条件下的杂交果实。研究认为,大白杜鹃与露珠杜鹃杂交亲和,杂交果实生长动态曲线为"双S"型,其形态成熟时的纵横径大小与其栽培条件直接相关。     

Genetic Relationships Among Verticillium dahliae Isolates from Cotton in Greece Based on Vegetative Compatibility

Vegetative compatibility groups of a collection of 71 Greek Verticillium dahliae isolates obtained from cotton plants were tested. Nit mutants were generated from single spore wild strains by selecting chlorate-resistant sectors on minimal medium amended with potassium chlorate, 25g/l. These mutants were tested against tester strains from the USA and Greece of the previously described VCGs 1, 2, 3 and 4. Forty-six of 71 isolates belonged to VCG2, because they were able to anastomose with the testers of this group, two isolates belonged to VCG4 and one to VCG1, while the 22 remaining strains could not be assigned to any of the identified VCGs. Our data demonstrated that wilt of cotton is caused only by V. dahliae in Greece, and VCG2 is the most commonly detected VCG. Some strains were found to be more virulent to cotton than other strains from the same VCG. This is the first report of VCG1 of Verticillium in Greece.     

Genetic diversity of the entomopathogen<Emphasis Type="Italic">Verticillium lecanii</Emphasis> on the basis of vegetative compatibility

Forty-three isolates ofVerticillium lecanii from insects, phytopathogenic fungi and other substrates were tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants.nit mutants were isolated from 42/43 strains examined. Twenty-one isolates were self-incompatible, and the remaining 21 isolates were divided into 14 vegetative compatibility groups (VCGs): ten containing only a single strain each, and the remaining four containing two to four isolates each. Members of isolates in each of these VCGs all shared the same IGS haplotype. Further, the isolates within a VCG were correlated with one another in part by fragment patterns of mt-LrDNA, -SrDNA, Bt-2 and H4 region, by PCR-RFLP and -SSCP, but not by dsRNA. Two isolates belonging to VL-J2 have high virulence to aphids, whereas strains from VL-J1 lack this character. These findings indicate that two VCGs (VL-J1 and -J2) may originate from two distinct clonal lineages. Alternatively, high VCG diversity and HSI frequency ofV. lecanii might be associated with an array of distinct lineages. These data not only suggest relationships among DNA polymorphisms, virulence, and VCG, but also demonstrate genetic heterogeneity ofV. lecanii. http://www.phytoparasitica.org posting Sept. 30, 2003.     

Pathogenic, Genetic and Molecular Characterisation of Fusarium oxysporum f.sp. lilii

Isolates of Fusarium oxysporum from lily were screened for pathogenicity, vegetative compatibility and DNA restriction fragment length polymorphisms, and compared to reference isolates of F. oxysporum f.sp. gladioli and F. oxysporum f.sp. tulipae to justify the distinction of F. oxysporum f.sp. lilii. Twenty-four isolates from different locations in The Netherlands (18 isolates), Italy (4 isolates), Poland and the United States (1 isolate each) shared unique RFLP patterns with probes D4 and pFOM7, while hybridization did not occur with a third probe (F9). Except for a self-incompatible isolate, these 24 isolates all belonged to a single vegetative compatibility group (VCG 0190). Isolates belonging to VCG 0190 were highly pathogenic to lily, but not to gladiolus or tulip, except for a single nonpathogenic isolate. Six saprophytic isolates of F. oxysporum from lily were nonpathogenic or only slightly aggressive to lily, gladiolus and tulip, belonged to unique VCGs and had distinct RFLP patterns. Three pathogenic isolates previously considered to belong to F. oxysporum f.sp. lilii were identified as F. proliferatum var. minus; all three belonged to the same VCG and shared unique RFLP patterns. These three isolates were moderately pathogenic to lily and nonpathogenic to gladiolus and tulip. The reference isolates of F. oxysporum f.sp. tulipae were pathogenic to tulip, but not to lily and gladiolus; they shared a distinct RFLP pattern, different from those encountered among pathogenic and saprophytic isolates from lily, and formed a separate new VCG (VCG 0230). Reference isolates of F. oxysporum f.sp. gladioli belonging to VCG 0340 proved pathogenic to both gladiolus and lily, but not to tulip. These isolates, as well as isolates belonging to VCGs 0341, 0342 and 0343 of F. oxysporum f.sp. gladioli, had RFLP patterns different from those encountered among the isolates from lily or tulip. These findings identify F. oxysporum f.sp. lilii as a single clonal lineage, distinct from F. oxysporum f.sp. gladioli and f.sp. tulipae.     

白菜新品种‘夏结球1号’

 以白菜弱亲和系90-1-1-2-3-94-3为母本, 弱亲和系90-1-5-1-2-94-6为父本配制而成的一代杂种‘夏结球1号’, 其生育期70～75 d, 株型紧凑, 结球性好, 叶片绿色, 结球紧实, 合抱, 球形指数为1.71, 单叶球质量为2～2.5 kg, 净菜率78% , 商品性好, 质地柔嫩, 生熟食均可, 口感好, 风味佳, 较抗软腐病。     

Discovery of two northern hemisphere Armillaria species on Proteaceae in South Africa

Armillaria root rot symptoms were observed on native Protea and Leucadendron (Proteaceae) species in Kirstenbosch Botanical Gardens in the Western Cape Province of South Africa. Intergenic spacer (IGS)-1 polymerase chain reaction (PCR) restriction fragment-length polymorphism (RFLP) profiling indicated the presence of at least two Armillaria species. The profiles of two isolates were identical to those of A. mellea s. str., originating in Europe. Phylogenetic analyses incorporating internal transcribed spacer (ITS) and IGS-1 sequence data identified the remaining isolates as closely related to A. calvescens , A. gallica , A. jezoensis and A. sinapina . These isolates displayed mating compatibility with A. gallica. From the RFLP profiles, sequencing results and sexual compatibility studies, it is concluded that the two species on Proteaceae in Kirstenbosch represent A. mellea and A. gallica . These are northern hemisphere fungi that have apparently been accidentally introduced into South Africa. This is the second report of Armillaria being introduced into South Africa. The introduction probably occurred early in the colonization of Cape Town, when potted plants from Europe were used to establish gardens.     

番荔枝花粉形态和授粉亲和性观察研究

【目的】研究两个番荔枝品种的花粉特性和授粉亲和性,为番荔枝的栽培和杂交育种提供理论依据。【方法】以广西大学果树育种基地的番荔枝为试材,对非洲骄傲和凤梨释迦的花粉进行电镜扫描;自交和正反交授粉,调查坐果率、荧光显微压片观察花粉萌发及生长动态。【结果】（1）非洲骄傲和凤梨释迦的花粉均为辐射对称型,外壁均为穴状纹孔,形状较为相似;赤道面观近椭圆形,极面观近圆形。（2）两个番荔枝品种自交和杂交后花粉在柱头上都能萌发,但品种间存在萌发速度的差异。授粉后1h,花粉管都开始萌发,但数量有差异,凤梨释迦的两个组合已经大量萌发,而非洲骄傲的则在14h才大量萌发。授粉24h,四个组合花粉管均进入子房。凤梨释迦的两个组合在48h后达到胚囊。【结论】非洲骄傲和凤梨释迦两个番荔枝品种的花粉形态相似,自交和杂交均有较好的亲和性。     

荔枝新品种‘岭丰糯’在海南的引种表现

摘 要 为了引进适宜海南种植的荔枝优良新品种,增加海南荔枝品种多样化。在海南澄迈永发科研基地引进‘岭丰糯’进行种植,观察其高接换种后砧穗亲和性、植物学特性、农艺性状、果实品质性状等表现。经过8年的引种观察与测试,结果表明：‘岭丰糯’进入稳定挂果期后,其果穗相对整齐,果实外观色泽鲜红美观,果肉风味香甜细腻,可溶性固形物含量达18.6%,焦核率95%以上,综合果实品质优良,平均每666.7 m2产量846.6 kg,果实成熟期为五月底至六月上旬,与当地主栽对照品种‘妃子笑’和‘白糖罂’错峰上市,具有良好的市场前景及发展优势,适合作为海南北部优异特色荔枝品种推广种植。     

云南光壳稻广亲和性与等位性研究

对云南光壳稻与籼粳测验种,广亲和品种间配制的单交,三交组合Ｆ１和Ｆ２及其亲本共１８１个材料在云南籼粳交错区,海南三亚和武汉进行育性鉴定表明,从１９个云南光壳稻中鉴定出１４个广亲和品种,尤其是花二早、花二早、,矮嗄,扎那嗄,扎那嗄１等品种的广亲和性较好,耐冷性也强于０．２４２８和Ｄｕｌａｒ,矮嗄一个生态适应性较好的广亲和品种,云南光壳稻与意大利粳稻巴利拉的生态地理远缘差异较大,花二早,末烈谷,木帮谷