The improvement of pore characteristics,remediation efficiency,and biotoxicity of petroleum-contaminated soil with the addition of bulking agent on field-scale biopile treatment

Journal of Soils and Sediments - The objectives of this study were to explore the effects of bulking agent and nutrients on the pore characteristics, remediation efficiency, and biotoxicity of...     

Analysis of genetic diversity in Prunus sibirica L. in inner Mongolia using SCoT molecular markers

Genetic Resources and Crop Evolution - Population genetic diversity contributes to the protection and utilization of germplasm resources, especially via genetic breeding. In the present study,...     

Variation in concentrations of major bioactive compounds in Hypericum perforatum L. from Lithuania

The growing demand for the medicinal plant, Hypericum perforatum, is not being met by available supply in many countries. The conditions for obtaining quality crude drug should be thoroughly studied to ensure adequate supply. The current study describes the variation of major bioactive compounds in different accessions of H. perforatum (Hypericaceae) in two floral development stages. Two extraction procedures were evaluated for the quantification of the major bioactive compounds in H. perforatum. The Soxhlet extraction technique was demonstrated to be more effective with higher extraction yields. The contents of rutin, hyperoside, quercitrin, quercetin, and 3,8″-biapigenin were determined by high performance liquid chromatography (HPLC). This procedure was used to establish the variation in the contents of flavonoids in the field-growing H. perforatum and to evaluate factors predetermining that variation with some practical implications for utilization. A significant difference in flavonoid contents between two floral development stages was detected. The results of the study showed that rutin prevailed during the budding stage, whereas quercitrin, quercetin, and 3,8″-biapigenin were dominant during the full-flowering stage. The contents of hyperoside were similar in both developmental stages of the plants. The highest amounts of the most bioactive compounds were observed in the full-flowering stage, which could therefore be considered the best stage for the harvesting of the raw material of H. perforatum, known as Hyperici herba in pharmaceutics. The study revealed evident intraspecific variations in the flavonoid contents of H. perforatum. Several chemotypes were recognized by qualitative and quantitative differences in flavonoids. Qualitative analysis of the flavonoid contents confirmed the presence of the chemotype of H. perforatum containing no rutin, though the chemotype with higher levels of both rutin and hyperoside was more frequent. The accessions of H. perforatum also showed remarkable differences in chemical composition depending on the origin of plants. Therefore, employing the correct developmental stage for the harvesting of the selected accessions of H. perforatum is highly recommended for the quality production of the drug Hyperici herba.     

斯洛伐克104份冬小麦种质资源农艺性状的分析及评价

为丰富我国冬小麦遗传多样性,为其遗传改良提供物质保障,对引进的104份斯洛伐克冬小麦种质资源的株高、株穗数、穗长、小穗数、穗粒数和千粒质量等主要农艺性状进行了调查分析。研究结果表明：引进的资源主要表现为株高偏高、穗子较大、千粒质量偏低的特点,且株高、穗长与千粒质量三性状均与对照品种存在极显著差异;6个性状变异系数幅度为0．08～0．37,变异系数的顺序为株穗数＞株高＝主茎穗粒数＞千粒质量＞穗长＞小穗数,表现了丰富的遗传多样性;64份冬性种质与40份春性种质的千粒质量差异达到极显著水平,株高和主茎穗粒数差异达到0．05显著水平,株穗数、穗长和小穗数差异不显著;株高与株穗数、株高与穗长、穗长与小穗数、穗长与穗粒数、小穗数与穗粒数呈极显著正相关,穗长与千粒质量、穗粒数与千粒质量呈显著正相关;聚类分析将104份种质分为4类;筛选出综合农艺性状优良的种质3份,可直接作为亲本材料应用于黄淮冬麦区的小麦遗传改良研究。     

Demodicosis in nine prairie dogs (Cynomys ludovicianus)

This case report describes the clinical signs and treatment of demodicosis in nine pet prairie dogs (Cynomys ludovicianus). Clinical records including history, clinical examination, microscopic evaluation and fungal culture of the skin lesions were available for all nine animals. In seven animals, blood was obtained for haematological and biochemical analyses. Clinical signs comprised bilaterally symmetrical alopecia extending from the middle part of the back down to the skin of the thighs and the dorsal and ventral parts of the tail. Demodex mites were found in skin scrapings from all cases. Treatment with amitraz at 250 p.p.m. resulted in resolution of lesions and hair regrowth. This is the first report of demodicosis in this species.     

小麦杂交种衡杂102丰产性节水性鉴定及分析

通过化学杀雄配制出杂交种衡杂102,表现出较好的高产性、节水性及适应性。水处理单位面积穗数、穗粒数超标优势为5.77%和3.97%,均达0.05显著水平;千粒重、产量超标优势为9.36%和12.21%,达0.01极显著水平。节水处理平均产量482.44 kg/667 m2,比对照增产8.29%,名列30个参试品种第1名。通过杂种优势利用,可以选育出高产、节水的小麦杂交种。     

Study of the genetic variability and similarity among and within Arachis villosulicarpa, A. pietrarellii and A. hypogaea through isoenzyme analysis

Arachis villosulicarpa is a perennial species cultivated for its soft and tasty seeds by indigenous inhabitants of the Mato Grosso State, Brazil. Besides A. hypogaea, this species is considered as the only species of Arachis which represents a valuable food source for human consumption. Due to the lack of knowledge concerning the genetic diversity of A. villosulicarpa, this study was conducted to evaluate the genetic variability of the accessions from the Germplasm Collection of CENARGEN/EMBRAPA (Brasília, DF, Brazil) and Instituto Agrono^mico (IAC, Campinas, SP, Brazil). In addition, the genetic similarity between A. villosulicarpa, the related wild species A. pietrarellii, and the cultivated peanut A. hypogaea cv. Tatu was evaluated. From the entire sample analyzed of A. villosulicarpa, the accession from Instituto Agrono^mico showed the highest indices of diversity for both enzymatic systems analyzed, pointing this accession as a promising source of genetic variabil ity that must be preserved in the Germplasm Bank. A high level of genetic similarity was observed between A. pietrarellii and A. villosulicarpa, supporting previous suggestions that A. pietrarellii could be the ancestral progenitor species of A. villosulicarpa or that both species originated from a common ancestor.     

Genetic variability at the Glu-1 loci in old and modern wheats (triticum aestivum L.) cultivated in Slovakia

The high molecular weight glutenin subunits (HMW-GS) composition at the Glu-1 complex loci, in 23 old original wheat genotypes cultivated in Slovakia several decades ago and 32 modern Slovak and Czech wheat cultivars growed in Slovakia at present were studied by SDS-PAGE. Some of the HMW-GS – subunit pairs 3+12, 17+18, and subunit 20, present in old historical wheats were missing in modern cultivars utilized in Slovakia nowadays. There were observed 15 different HMW-GS encoded by 11 alleles or allelic pairs in old genotypes. Lower number of different HMW-GS and competent alleles were observed in a set of modern wheat cultivars – 11 different HMW glutenin subunits encoded by 8 alleles or allelic pairs. The same number of different HMW-GS patterns was revealed in both sets of wheats. From the point of view of genetic variability, it could be concluded that long-term effort of breeders and decreasing of cultivation of landraces and old cultivars are associated with the loss of several HMW-GS alleles and decreasing of genetic variability of wheats. Molecular characterization can reveal broad allelic variability of old wheat genotypes and landraces. Their maintenance in genetic resource collections can prevent losses of these interesting genes.     

Case studies on breeding systems and its consequences for germplasm conservation

The first results of a study relative to the demography of wild Lima bean (Phaseolus lunatus L.) populations in the Central Valley of Costa Rica are presented. Six wild populations were selected in the four mainly representative ecological zones of this region and several 1 m₂ quadrats were demarcated in order to determine the vital rates (fecundity, survival, growth and mortality) of the individuals within each population. These data were collected during two years from 3000 labelled individuals and combined with those relative to the soil seed bank and the seed dormancy to propose a demographic model for a hypothetical mean wild population based on the projection matrix theory. This model helps to determine the growth rate of the population, the stability of its structure and, by using a sensitivity analysis, reveals also the factors most constraining for the population survival. Population behaviour under natural conditions and human pressure are simulated, which allow to propose management practices for in situ conservation.     

Growth and wood density of Pinus taeda L. as affected by shelterwood harvest in a two-aged stand in Southern Brazil

Pine plantations are an important wood source in Brazil, with Pinus taeda being most frequently planted. Most pinewood is directed to the paper and pulp industry, but there is an increasing demand for wood for solid end-uses, requiring large stems from longer rotations which can be obtained using P. taeda as the canopy in two-aged stands. We evaluated radial growth and wood density at different stem heights of P. taeda in the highlands of Southern Brazil over a production period of 36 years and subjected to shelterwood harvest. Cross-sectional disks were obtained from 15 trees in different stem heights; 10 were used for growth analyses and 5 for growth and density analyses. We used disk images and X-ray techniques for growth and density analyses, respectively. Samples were analyzed for ring (width and density), earlywood, and latewood (width, density, and proportion). Ring width varied between 0.4 and 1.7 cm, with the widest rings in the first years (3–5 years.) of growth. Ring density increased with age, with higher densities on the lower stem portions. Mature wood started to be formed from the 16th ring onwards. Shelterwood harvest affected both ring width and density, but the effects on ring width lasted for at least 5 years, while the effects on wood density were short-lasting. Mature P. taeda trees increased their size after the shelterwood harvest without compromising their wood density. Longer production periods of P. taeda as retained trees in the canopy of two-aged stands provide high-quality wood for structural purposes.