河北南部杨树苗圃春季地下害虫群落结构研究

系统调查了河北南部两种不同类型杨树苗圃地下害虫昆虫群落结构组成。水浇地苗圃地下害虫优势种为小黄鳃金龟,旱地苗圃优势种为黑绒鳃金龟;水浇地杨树苗圃地下害虫群落丰富度、个体数和多样性指数都高于旱地苗圃。在春季,地下害虫的种类和数量在不同的土壤深度随时间变化而变化,从2月下旬到4月中旬,0~5cm的昆虫种类和数量不断增加,10~20cm地下害虫呈下降趋势。     

Biocontrol traits of two Paenibacillus polymyxa strains SQR‐21 and WR‐2 in response to fusaric acid,a phytotoxin produced by Fusarium species

The aim of the present study was to investigate the effects of the phytotoxin fusaric acid (FA) on the biocontrol traits of two biocontrol strains Paenibacillus polymyxa WR‐2 and SQR‐21. The results showed that the growth of both WR‐2 and SQR‐21 decreased with increasing FA concentration, and at 70 and 80 μg mL^?1 FA, respectively, the strains were unable to grow. The biocontrol traits of both strains were negatively affected by FA concentration higher than 2·5 μg mL^?1. However, at 2·5 μg mL^?1 FA, biofilm formation and root colonization were not affected and there was even a positive effect on the production of spores and hydrolytic enzymes (protease and β‐l,3‐glucanase). The production of fusaricidin‐type antifungal compounds was increased with an increase in FA concentration up to 50 and 60 μg mL^?1 for WR‐2 and SQR‐21, respectively. The production of antifungal volatile organic compounds by WR‐2 and SQR‐21 was increased only at 2·5 μg mL^?1 FA. The effect of FA on the overall metabolic activity of WR‐2 and SQR‐21 was also determined. This study will help to understand the response of P. polymyxa strains to FA and will help to improve their biocontrol efficiency.     

Long-term fertilisation regimes affect the composition of the alkaline phosphomonoesterase encoding microbial community of a vertisol and its derivative soil fractions

Alkaline phosphomonoesterase (ALP) mainly originates from soil microbial secretion and plays a crucial role in the turnover of soil phosphorus (P). To examine the response of ALP-encoding microbial communities (analysed for the biomarker of the ALP gene, phoD) of soils and derivative soil fractions to different fertilisation regimes, soil samples were collected from a long-term experimental field (over 35 years). The different organic P (Po) pools of soil fractions and the ALP activity of soil were also determined. Compared with chemical-only fertilised soils, the ALP activity was 232–815% higher in organic-amended soils, and the highest enzyme activity was observed in the organic-only fertilised treatment. The abundance of the phoD gene harbouring in soil fractions, determined by quantitative PCR (qPCR), was affected by different fertilisations. The highest abundance of the phoD gene was generally detected in the 2–63-μm-sized fraction (silt), but most phoD-encoding microbial species were associated to the 0.1–2-μm-sized fraction (clay) in the chemical-only fertilised soil. The contents of labile Po (LPo), moderately labile Po (MLPo) and fulvic acid-associated Po (FAPo) were significantly correlated with the phoD gene abundance, whereas only LPo content was significantly correlated with the ALP activity. The dominant phoD-encoding phylas were Actinobacteria and Proteobacteria, according to a high-throughput sequencing. Bradyrhizobium, a N₂-fixer identified as a phoD-encoding genus, showed the highest abundance in fertilised soils. The abundance of Bradyrhizobium, Streptomyces, Modestobacter, Lysobacter, Frankia and Burkholderia increased with the organic-only amendment and was significantly correlated with the ALP activity. According to structure equation models (SEM), pH and LPo content significantly and directly affected the ALP activity; the soil organic C (C_org) content was related to composition and abundances of phoD-harbouring microbial communities; since both microbial properties were correlated to the ALP activity, the C_org content was indirectly related to the ALP activity. In conclusion, soil management practices can be used to optimise the contents of soil available P and the organic P with regulation of soil ALP activity and the community composition of corresponding microbes.     

The role of forskolin as a lipolytic stimulator during in vitro oocyte maturation and the in vitro embryo production of livestock

Cryopreservation is a modern technique which assists in the preservation of genetic material from oocytes and embryos for a long time. However, elevated vulnerability to cryopreservation due to the large accumulation of intracellular lipids within oocytes or embryos avoids success of this method. These lipids remain the main crucial factor limiting survival rates of oocytes and embryos after thawing. Lipid ingathering in the oocyte cytoplasm augments lipid peroxidation (LPO) and oxidative stress increases the apoptosis process, declines the viability after thawing, declines cytoskeleton actin filament injuries, lowers the blastocyst rates and reduces cryotolerance in the early stages of embryo development. There have been several attempts to reduce the ingathering of intracellular lipids in oocytes or embryos during the cryopreservation process, in that way enhancing the competence of cryopreserved oocytes or embryos and increasing their viability. One of the most applied agents for chemical delipidation is forskolin. Forskolin exhibited a possible part in improving the oocytes cryopreservation through stimulating cyclic adenosine monophosphate (cAMP) production. The main purpose of cAMP modulation is to provide energy to sustain the mammalian oocytes´ meiotic arrest. The purpose of the existing article is to assess and offer more evidence concerning the forskolin utilization as a modulator of cAMP during the cryopreservation of oocytes and its influence on meiosis completion and the reorganization of cytoplasm, which are prerequisites for the development of oocytes in addition to the contribution to fertilization and subsequently, the development of embryos.     

The effect of haplotypes in the promoter region of SIRT4 gene on the ultrasound traits in Qinchuan cattle

Tropical Animal Health and Production - Sirtuin 4 (SIRT4) belongs to the mitochondrial sirtuin class of NAD+-dependent protein deacylases. This gene plays an important role in the regulation of...     

Effect of pruned material,extracts, and polyphenols of tea on enzyme activities and microbial community structure in soil

Pruning is a regular management practice performed in tea fields, but its effects on soil properties and microbial community structures have not been well explored. Effects of tea pruned material, tea extracts, and tea polyphenols application on soil properties and microbial characteristics, including pH, soil enzyme activities, culturable microbial population, and bacterial community, were investigated in a pot-incubation experiment lasting for 10 weeks. Results indicated that returning of tea pruned material or its extracts significantly increased the soil pH as compared to control. The soil invertase and urease activities, as well as the culturable microbial population treated with pruned material were much higher than those in control, while polyphenol oxidase activity was similar among different treatments. Denaturing gradient gel electrophoresis analysis of bacterial community indicated that the Shannon’s diversity index (H) of all nine treatments receiving additives slightly decreased as compared to control. Pruning returning specifically induced several beneficial bacterial species, including Brevibacterium sp. and Burkholderia sp. In conclusion, pruning returning alleviated soil acidification, induced soil enzyme activities, stimulated culturable microbial population, and reshaped the microbial community. This research suggests that this management could be applied as an alternative agricultural practice in tea cultivation.     

Preparation and Optimization of Amino Acid Chelated Micronutrient Fertilizer by Hydrolyzation of Chicken Waste Feathers and the Effects on Growth of Rice

For the preparation of amino acid chelated fertilizer, chicken feathers were hydrolyzed with sulfuric acid (H₂SO₄; 6M) and potassium hydroxide (KOH; 6M) separately in the presence of different catalysts. Under acidic conditions, the catalyst zinc sulfate, gave minimum ammonium but a maximum conversion rate of organic nitrogen (N) into amino acids (19% higher than control). Under alkaline conditions, sodium sulfide showed maximum amino acid-N and conversion rate (37% higher than control). The catalyst doses showed a continuous increase in the conversion rate and were highest at 12%. The ratio of 1:3 feathers: hydrolytic agent showed maximum conversion rate. Hydrolytic time had a nonsignificant effect under acidic conditions, but under alkaline conditions a hydrolytic time of 14 h gave the maximum conversion rate. The chelation experiment results showed that the ratios (2:1, 2.5:1, and 3:1) showed almost equal chelation rates, except the 1:1 ratio of hydrolysis product to salt. Iron (Fe), copper (Cu), and manganese (Mn) showed maximum chelation rates under acidic pH, while zinc (Zn) showed maximum chelation rate at an alkaline pH. Temperature and chelation time had a nonsignificant effect on chelation rate. Comparative study results of amino acid chelated Zn and Fe fertilizers, ethylenediaminetetraacetic acid (EDTA) chelated Zn and Fe fertilizers, and zinc sulfate (ZnSO₄) and iron sulfate (FeSO₄) fertilizer foliar application to upland rice showed that a 1/100 dilution of amino acid chelated Zn and Fe fertilizers increased growth parameters from 22–73%, while EDTA chelated Zn and Fe fertilizers caused an increase of 15–63%, and ZnSO₄ and FeSO₄ increased growth parameters from 11–35% over the control. After fertilizer application, increase in chlorophyll contents was 11–17%, 3–6%, and 8–12%, respectively, over control. Therefore, amino acid chelated micronutrient fertilizer is used in small amounts, has a low cost, and high rates of return.     

Responses of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="Italic">niveum</Emphasis> to exogenously added sinapic acid in vitro

To assess the influence of phenolic acids from plant root exudates on soil pathogens, we studied the effect of sinapic acid added to chemically defined media on the growth and virulence factors of Fusarium oxysporum f. sp. niveum. Sinapic acid inhibited the growth and conidial formation and germination of F. oxysporum f. sp. niveum by 6.7–8.8% and 11.2–37.3%, respectively. Mycotoxin production by F. oxysporum f. sp. niveum was stimulated by 81.6–230.7%. Pectinase, proteinase, cellulase, and amylase activities were stimulated at a lower concentration of sinapic acid, while they were inhibited at a higher concentration. It is concluded that sinapic acid inhibited the growth and conidial germination of F. oxysporum f. sp. niveum and decreased the pathogenic enzymes’ activity at higher doses.     

槭树绵粉蚧雄性生殖器官和精子超微结构观察

槭树绵粉蚧是我国北方林木的一种重要害虫。本文详细描述了其雄性生殖器官和精子的超微结构。每精子束有精子 1 3～1 8根 ,平均 1 6根。精子内的微管 52～ 54个 ,平均 53个 ,在无核区呈 3圈完全同心圆排列 ,有核区呈 2 圈不完全同心圆排列。