Seedling emergence,coleoptile length,and plant height relationships in crosses of dwarf and standard-height wheats

Summary Seedling emergence was closely correlated with coleoptile length and plant height among parents, F₂ and F₃, populations of crosses involving dwarf wheats Olesen Dwarf (CI 14497), Norin 10 derivative D6301, Tom Thumb derivative D6899, and the standard-height varieties Ramona 50 and Nainari 60. Genetic mechanisms that governed plant height also influenced coleoptile length, but the relative effects of genes showing dominant or epistatic effects appeared to be different. With respect to the two parents involved in each of 15 crosses, mean F₂ coleoptile lengths were consistently closer to the low parent value than were corresponding mean F₂ plant heights. A slight curvilinear relationship was also found between coleoptile length and plant height of F₃ lines. The results suggest that selection of semidwarf wheats with long coleoptiles and improved emergence properties from crosses involving the dwarf wheats of this study would be unlikely.     

Top Dressing of Feed with Desiccated Chlamydospores of Duddingtonia flagrans for Biological Control of the Pre-Parasitic Stages of Ovine Haemonchus contortus

Feeding trials were conducted with stall-fed sheep parasitized with Haemonchus contortus. For 10 days they were offered 250 g of a concentrate feed that had been top-dressed with desiccated chlamydospores of Duddingtonia flagrans at 1×10⁵, 5×10⁵, 1×10⁶ or 2×10⁶ chlamydospores/kg body weight. Pooled faeces from each group on day 7 of spore feeding were spread on different pasture plots. On day 28 after the start of spore feeding, further pooled faeces from each group were spread on the same plots. The larval burdens on the plots were monitored for 2 months and the larval harvest from in vitro faecal cultures were monitored regularly. The application of 1×10⁶ or more spores/kg body weight virtually eliminated larvae from both the pasture and the faecal cultures. The application of as few as 1×10⁵ spores/kg body weight had a profound impact on larval recovery. The effect persisted while the spores were being fed but not for more than 4 days following discontinuation of spore feeding. Top dressing supplementary feed with dried chlamydospores offers a potential way of using D. flagrans for biological control of the pre-parasitic stages of H. contortus.     

重庆上市公司互保圈现象的会计思考

在市场经济环境下，贷款担保作为上市公司融通资金的一种方式，是企业的一种正常的经营行为。它可以减少交易风险、促进资本市场发展。然而，目前由于种种原因，上市公司互保不仅没有起到化解市场风险的作用，反而加大了证券市场和金融市场的风险，严重扰乱了资本市场的正常运行。因此，本文拟通过思考重庆“互保圈”现象，分析“互保圈”形成的原因及危害，并由此提出相应的对策与建议。     

Genetic divergence of kingfish from Japan, Australia and New Zealand inferred by microsatellite DNA and mitochondrial DNA control region markers

ABSTRACT: Genetic polymorphism in kingfish, collected from coastal waters of Japan, Australia and New Zealand, were examined using microsatellite (MS) DNA and mitochondrial DNA (mtDNA) control region markers. Sixteen to 25.7 alleles per locus were observed in three MS markers, while the average observed (and expected) heterozygosities were 0.782 (0.918), 0.750 (0.809) and 0.650 (0.888) for Australian, Japanese and New Zealand kingfish, respectively. Twelve mtDNA haplotypes were detected by the digestion of control region sequences with five endonucleases: Hae III, Hinf I Mbo I, Rsa I and Taq I. Significant genetic divergence was observed between the kingfish population from Japan and those from Australia–New Zealand. There was no significant differentiation among the Australian and New Zealand population samples.     

Species identification method for <Emphasis Type="Italic">Scombrops boops</Emphasis> and <Emphasis Type="Italic">Scombrops gilberti</Emphasis> based on polymerase chain reaction-restriction fragment length polymorphism analysis of mitochondrial DNA

ABSTRACT:   Gnomefish Scombrops boops and Scombrops gilberti are commercially important fishes in Japan, but these species are often confused in the markets because of their morphological similarity. To identify these two species, we performed nucleotide sequencing and restriction fragment length polymorphism (RFLP) analysis on 16S ribosomal RNA (rRNA) gene and the control region in mitochondrial DNA. Five and 12 nucleotide substitutions were observed between species in the 777-bp 16S rRNA gene and 471-bp control region, respectively. Diagnostic restriction sites for discriminating between S. boops and S. gilberti were found in the 16S rRNA gene, but not in the control region. Polymerase chain reaction (PCR)–RFLP analysis using two enzymes, Eco NI and Mva I, clearly discriminated between S. boops and S. gilberti identified by meristic characters. The PCR–RFLP analysis identified most of the 168 Scombrops young caught in the coastal waters of the Izu and Miura peninsulas as S. boops , suggesting that S. gilberti juveniles are rare in this area.     

Structure Design of Large-scale Sow House with Fermentation Bed

ln this research, the whole contact-type large-scale sow house with fer-mentation bed was designed. The planning area of the entire piggery was 5 700 m2 with workplace and green belts. The sow house was 93 m long and 33 m wide, a total of 3 069 m2, including office area of 60 m2 and aisle area of 107 m2. The fer-mentation bed had an area of 2 902 m2 with length of 88.7 m and width of 27.7 m. lts area accounted for 95% of the total area of sow house. The fermentation mattress had a depth of 80 cm, and had a volume of 2 321 m3, equivalent to 733 t of coconut chaff and rice chaff. On a large fermentation bed, the areas for boars, replacement gilts, pregnant sows, obstetric tables, nursery pigs, etc. were designed. The large-scale sow house with fermentation bed was equipped with the automatic feeding system, automatic sprinkler system, automatic positioning column for preg-nant sows, sows＇ obstetric table system, fanning wet curtain cooling system, video monitoring system, environmental monitoring （light, temperature, water, humidity, CO2, NH3） and automatic control system. Every farming area was equipped with feeding trough and water trough. The water though was fixed with overflow pipe for removing the extra water. The house could hold 500-head sows. Each sow occu-pied 4.9 m2 of the fermentation bed in average. The designed sow house had a maximum annual output of 10 000 piglets.     

KS－1型双功能控湿仪的研制

ＫＳ－１型控湿仪由集成运算放大器、５５５时基电路、固态继电器等先进的电子器件组成，具有双功能、自动控制灵敏、结构简单、使用方便、经济实用等特点。本文介绍了该控湿仪的设计思想、基本原理和性能特点，并对５５５集成芯片组成的单稳、控时电路作了具体的分析     

Enchytraeids and nematophagous fungi in soil microcosms

In small containers of soil in the laboratory, the enchytraeid Enchytraeus crypticus destroyed colonies of the nematophagous fungus Hirsutella rhossiliensis growing from pelletized hyphae, and reduced biological control of the root-knot nematode Meloidogyne javanica. The enchytraeid also reduced the population densities of the nematode-trapping fungi Monacrosporium gephyropagum, Arthrobotrys thaumasia, and A. haptotyla. Because addition of pelletized hyphae caused rapid and large increases in numbers of E. crypticus, the enchytraeid apparently interfered with biological control by ingesting and consuming the fungi. Received: 15 January 1997