Molecular divergence and application of the ITS-5.8S rDNA and RUBISCO spacer in <Emphasis Type="Italic">Porphyra haitanensis</Emphasis> Chang et Zheng (Bangiales,Rhodophyta)

To select a reliable and sensitive method for discriminating strains of Porphyra haitanensis, the nucleotide sequence of the internal transcribed spacer 1 to internal transcribed spacer 2 regions (ITS-5.8S) of nuclear ribosomal DNA and the intergenic spacer region of RUBISCO were compared in five wild and five cultivated Porphyra haitanensis strains. Based on molecular analyses, sequences of ITS-5.8S (about 1,210 bp) could be divided into three regions: ITS1, 5.8S, and ITS2. The ITS1 and ITS2 sequences of each strain differed, even between individuals collected from the same site. In contrast, 5.8S rDNA and RUBISCO spacer sequences were identical among the ten P. haitanensis strains, although differences were found among different Porphyra species. Phylogenetic analysis also supported these conclusions. These sequence features of highly conserved regions and diversified regions that occurred repeatedly in ITS-5.8S could be useful in discriminating germplasm of P. haitanensis strains or Porphyra species. In contrast, the RUBISCO spacer is only suitable for identifying Porphyra species. New coupled primers were designed to amplify only the 5.8S rDNA and ITS2 region of Porphyra. The sequences of these amplified fragments can be readily used to identify germplasm or to perform phylogenetic analysis of Porphyra spp.     

机械运输对伊朗北部山林陡峭集材道土壤的干扰

A study was conducted to investigate the effects of skid trail slope and traffic levels on soil disturbances at two soil depths (0–10 and 10–20 cm). The treatments were set at four traffic levels (2, 7, 12 and 20), two slope classes (<20% and >20%) and two soil depths (0–10 and 10–20 cm). Results show that skidder traffic, longitudinal slope and soil depth have significant effect on soil bulk density in skid trail. Comparison of average soil bulk density in different traffic levels shows that there are significant differences in average bulk density between different traffic levels and control (p<0.05). The average bulk densities in different slopes and soil depths are significantly increased with increase in traffic levels, maximized at 12 passes (p<0.05), but there are no significant differences between 12 and 20 passes. The interaction effects between traffic and soil depth are significant (F _0.05,3=0.109, p<0.001). For all traffic treatments, there are significant differences in soil moisture content between the two slope classes and the two depths (p<0.001). However, the interaction effects between traffic levels and slope classes are not significant (p >0.05), although skidder traffic and slope affected soil moisture content.     

Influence of Humic Products on Soil Health and Potato Production

Since 1900, soil organic matter (SOM) in farmlands worldwide has declined drastically as a result of carbon turnover and cropping systems. Over the past 17 years, research trials were established to evaluate the efficacy of different commercial humates products on potato production. Data from humic acid (HA) trials showed that different cropping systems responded differently to different products in relation to yield and quality. Important qualifying factors included: source; concentration; processing; chelating or complexing capacity of the humic acid products; functional groups (Carboxyl; Phenol; Hydroxyl; Ketone; Ester; Ether; Amine), rotation and soil quality factors; consistency of the product in enhancing yield and quality of potato crops; mineralization effect; and influence on fertilizer use efficiency. Properties of humic substances, major constituents of soil organic matter, include chelation, mineralization, buffer effect, clay mineral-organic interaction, and cation exchange. Humates increase phosphorus availability by complexing ions into stable compounds, allowing the phosphorus ion to remain exchangeable for plants’ uptake. Collectively, the consistent use of good quality products in our replicated research plots in different years resulted in a yield increase from 11.4% to the maximum of 22.3%. Over the past decade, there has been a major increase in the quality of research and development of organic and humic acid products by some well-established manufacturers. Our experimentations with these commercial products showed an increase in the yield and quality of crops.     

Studies on hollownesss regulation and properties of crosslinked hollow phenolic fibers

The hollowness of crosslinked hollow phenolic fibers was regulated successfully from 9 % to 80 % by adjusting the curing temperature of the partially crosslinked fibers. The partially crosslinked fibers was studied in detail by mass gained, tensile strength, solvent dissolution, SEM, IR, and TG analysis, and the prepared hollow phenolic fibers with different degrees of hollowness were characterized with SEM, tensile strength, TG-DSC and TG-MS. The results show that the factor determining the hollowness is the crosslinked extent of the partially crosslinked fibers and the hollow fibers with different degrees of hollowness have similar crosslinkage, mechanical properties and thermal stability.     

Efficiency of methods applied for goat estrous synchronization in subtropical monsoonal climate zone of Southwest China

Two experiments were undertaken to select the efficient method applied for goat estrous synchronization. In experiment 1, a total of 120 does (Capra hircus) were divided into five groups with a randomized block design, and the does of treatment 1 were synchronized by intravaginal sponges impregnated with 30 mg Levonorgestrel inserted for 10 days. Does of treatments 2, 3, and 4 were treated with further injection of 25 IU follicle-stimulating hormone (FSH), 0.05 mg prostaglandin F2 alpha (PGF_2α), and 25 IU FSH + 0.05 mg PGF_2α at sponge withdrawal, respectively. The does in the control group (n = 40) without estrous synchronization treatment and natural estrous does were observed. In experiment 2, a total of 140 does in five goat farms in breeding and non-breeding seasons were treated with the selective efficient procedure. The results presented that all the employed treatments were capable of inducing and synchronizing estrous goats. According to estrous response and economy, the use of intravaginal sponges impregnated with 30 mg Levonorgestrel and 0.05 mg PGF_2α (treatment 3) is the first choice for estrous synchronization, and 95.0% of synchronized does demonstrated estrus, which was significantly higher than that of treatment 1 (P < 0.05) and control group (P < 0.01). The percentages of ovulating of treatments 3 and 4 were the same (95.0%), which were significantly higher than that of treatment 1 (P < 0.01). The ovulation rates among different groups were not significant (P > 0.05). When the selective procedure was applied to five goat farms, 85.7% (120/140) of does demonstrated estrus, and the kidding percentage, litter size, and prolificacy rate were 53.6%, 0.95, and 177%, respectively.     

Effects of additive iron on growth,tissue distribution,haematology and immunology of gilthead sea bream, <Emphasis Type="Italic">Sparus aurata</Emphasis>

The comparative effects of iron-supplemented levels on growth, tissue distribution, haematology and immunology of gilthead sea bream, Sparus aurata (2 g) were investigated, using four organic (50, 100, 200, 300 mg ORG/kg diet) and one inorganic iron source (200 INOR mg/kg diet). Fish were treated for 12 weeks with the experimental diets and maintained at a water temperature of 19–22°C. Growth (final weight and specific growth rate), tissue distribution (spleen, liver and muscle), haematological parameters (red blood cells, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration) and non-specific immune indexes (respiratory burst activity and antibacterial activity of serum) were analysed. No significant differences were found in growth and iron tissue distribution among the tested groups. Red blood cell counting was statistically higher in fish given 50 ORG, 100 ORG, 200 ORG and 200 INOR feeds. However, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration were not significantly affected by increasing dietary iron. Fish receiving the 100 ORG diet had the best performance with respect to the respiratory burst activity and significantly higher values for antibacterial activity of serum were obtained in fish fed with the 300 ORG diet. The present findings provided no clear evidence of the optimum iron concentration. However, there was adequate indication that iron supplementation enhanced the performance of gilthead sea bream, mainly from a haematological and immunological point of view.     

莨菪烷碱防治蔬菜根结线虫药效研究

本文报道了莨菪烷碱（hyoscyamine)防治蔬菜根结线虫（Meloidogyne incognita)效果，该制剂以有效成分用量7.5-10.5g/667m^2对水稀释后穴施，药后150d对线虫防效达73.78%-82.84%，优于3％米乐尔（isazofos)颗粒剂有效成分用量150g/667m^2穴施药后150d的防效65．30％，并有一定刺激生长作用，有较高推广应用价值。     

小果菘兰营养器官的结构植物学研究

本研究用石蜡切片法，对小果菘兰的根，茎，叶进行观察。其特点：根的次生木质部导管大。它以周皮代替表皮。茎，叶表皮细胞都有较厚的外壁和角质层。茎的髓部具有很大型的薄壁细胞。叶的栅栏组织发达，二层细胞，二面叶，主脉有３个维管束，排列成三角状。     

Molecular breeding for virus resistant potato plants

To engineer resistance against potato virus X (PVX), the viral coat protein (CP) gene has been introduced into two potato cultivars. Stable expression of the gene in transgenic clones throughout the growing season has been obtained and resulted in considerably increased virus resistance. With varying frequencies depending on the original cultivar used, true-to-type PVX resistant transgenic clones have been obtained. Since deviant light sprout characteristics were invariably associated with aberrations in plant phenotype, they can be used in procedures to early screen for deviations. Furthermore, it has been possible to unequivocally discriminate between the original untransformed and independent transgenic cultivars. Although no relation has been found between the presence, if any, of the CP of potato virus Y (PVY) or potato leafroll virus (PLRV) in CP gene transgenic potato, appreciable levels of resistance to these viruses has been obtained. This suggests that the mechanism by which a viral CP gene in the potato genome evokes resistance, differs amongst various viruses.