• Korean Chemical Engineering Research
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• 제54권6호
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• pp.822-829
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• 2016

Our aim was to optimize the production of cellulase-free thermoactive xylanase by Aureobasidium pullulans CBS 135684 with statistical methodology based on experimental designs. Among eleven variables, the nutrient sources that had significant effect on xylanase production were corncob, $(NH_4)_2SO_4$, xylose, $KH_2PO_4$ and tween 80, identified by the initial screening method of Plackett-Burman. The optimum concentrations of these five components were subsequently investigated using response surface methodology. The optimal concentrations ($g{\cdot}l^{-1}$) for maximum production of xylanase were corncob, 39.0; $(NH_4)_2SO_4$, 3.0; xylose, 1.8; $KH_2PO_4$ 1.4; and tween 80, 1.4, respectively. An improved xylanase yield of $8.74{\pm}0.84U{\cdot}ml^{-1}$ was obtained with optimized medium which is 2.1-fold higher production than previously obtained results ($4.10{\pm}0.10U{\cdot}ml^{-1}$) after 48 h of cultivation. In addition, the xylanase production under optimal condition reached $10.09{\pm}0.27U{\cdot}ml^{-1}$ after 72 h of cultivation.

• ALGAE
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• 제31권1호
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• pp.33-39
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• 2016

Blooms of macroalgae have grown over the planet in recent decades as a possible result of eutrophication of coastal waters. Visually, a bloom forming can be identified by dominant presence of an organism at the expense of others. In mid-January 2014, a forming bloom of red algae was detected on the beach of Garopaba, Santa Catarina State, Brazil. This aroused the interest of tourists and locals as well as the scientific community. Thus, the objective of this study was to characterize and quantify the photosynthetic floating organisms contributing to this phenomenon. In addition, we qualitatively compared algal composition of the bloom to those deposited in the post-beach area and the adjacent rocky shore community. Five sampling points in random patches of floating material were defined. At each point, five replicates were taken with a cube of 32,768 cm³, resulting in a total of 25 samples. Samples were collected in the inner area enclosed by a PVC quadrate of about 900 cm² from the shore and the specimens found in post-beach zone (wrack). Twenty-four taxa of macroalgae were found in the bloom, with Aglaothamnion uruguayense as the dominance one. Ten taxa were found on shore. Only four taxa were found in the post-beach area. The biomass estimated for A. uruguayense in the floating material was 8.35 tons with an estimated area of 52,770 m² . It is possible that this huge biomass value of the bloom is related to the local nutrient intake, and our results reinforce the necessity of coastal integrative management initiatives.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.739-749
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• 2013

The seasonal and spatial diversity of picocyanobacteria (Pcy) in lakes of the Great Mazurian Lakes (GLM) system was examined by DGGE analysis of molecular markers derived from the 16S-23S internal transcribed spacer (ITS) of the ribosomal operon and the phycocyanin operon (cpcBA-IGS). The study of nine lakes, ranging from mesotrophy to hypereutrophy, demonstrated seasonal variance of Pcy. The richness and Shannon diversity index calculated on the basis of both markers were higher in spring and lower in early and late summer. No statistically significant relationships were found between the markers and trophic status of the studied lakes or Pcy abundance. There were, however, statistically significant relationships between the diversity indices and sampling time. The analysis pointed to a different distribution of the two markers. The ITS marker exhibited more unique sequences in time and space, whereas a greater role for common and ubiquitous sequences was indicated by the cpcBA-IGS data. Examination of the Pcy community structure demonstrated that communities were grouped in highly similar clusters according to sampling season/time rather than to the trophic status of the lake. Our results suggest that time is more important than trophic status in shaping the diversity and structure of Pcy communities. The seasonal changes in picocyanobacteria and differences in diversity and community structures are discussed in the context of well-established ecological hypotheses: the PEG model, intermediate disturbance hypothesis (IDH), and horizontal gene transfer (HGT).

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1984년도 학술대회지
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• pp.45-48
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• 1984

인삼근에서 유래된 캘루스중 배분화 유조직과 배분화가 되지 않는 유조직에 있어서 Indol-3-acetic acid (IAA) 및 Indole-3-acetyl-L-aspartate(IAAsp) 함량을 Ion-pair reverse phase HPLC 기법을 이용하여 분석 비교하였다. 배분화 유조직의 IAA 및 IAAsp 함량은 배분화가 불가능한 유조직에 비해 각각 7 및 18배 함량이 높았다. 배분화가 되지 않은 캘루스로부터 얻은 추출물의 HPLC 프로파일상의 인돌 화합물 피크 부근에 특이한 미확인 피크가 나타났다. 이와 같은 분명한 차이는 배상체 발생 잠재력이 높은 유조직을 얻기 위한 배양조직을 선별하기 위한 확실한 파라메타로 이용될 수 있을 것이다.

• 한국작물학회지
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• 제49권2호
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• pp.131-135
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• 2004

To find out the responses of soybean genotypes in terms of different levels of irrigation with the aim of evaluating the growth, yield, and its optimum levels of irrigation, an experiment was conducted at the Field of Crop Botany Department, Bangladesh Agricultural University, Mymensingh during the period from November 2000 to February 2001. Five levels of irrigation viz. $\textrm{I}_0$: no irrigation, $\textrm{I}_1$: one time irrigation at 20 days after sowing (DAS), $\textrm{I}_2$:two times irrigation at 20 and 40 DAS, $\textrm{I}_3$: three times irrigation at 20, 40, and 60 DAS, and $\textrm{I}_4$: four times irrigation at 20, 40, 60, and 80 DAS and three genotypes of soybean viz. BS-3, BS-16, and BS-60 were used in this experiment. The crop was grown in a split plot design having three replications. The plant height, leaf area index, crop growth rate, shoot dry weight, branches $\textrm{plantI}_{-1}$, filled pods $\textrm{plantI}_{-1}$, seeds $\textrm{plantI}_{-1}$, seed yield, and harvest index were influenced significantly by irrigation and these were found to be highest at three times irrigation except branches $\textrm{plantI}_{-1}$. The chlorophyll content increased but empty pods $\textrm{plantI}_{-1}$ decreased with increase in irrigation levels. Genotypes of soybean varied significantly in terms of growth attributes at various growth stages except shoot dry weight at 90 DAS. The genotype BS-3 performed better compared to other genotypes and gave maximum seed yield.

• Mycobiology
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• 제32권3호
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• pp.139-147
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• 2004

A severe damping-off disease of bush okra caused by Pythium aphanidermatum, was diagnosed in plastic houses in Der Attia village, 15 km southwest of El-Minia city, Egypt, during the winter of 2001. Bush okra seedlings showed low emergence with bare patches inside the plastic houses. Seedlings that escaped pre-emergence damping-off showed poor growth, stunting and eventually collapsed. Examination of the infected tissues confirmed only Pythium aphanidermatum, showing its typical intercalary antheridia, and lobulate zoosporangia. P. aphanidermatum was shown to be pathogenic on bush okra under pot and field experiments. Bacteria making inhibition zones against the damping-off fungus P. aphanidermatum were selected. Agar discs from rhizosphere soil of bush okra containing colonies were transferred onto agar plate culture of P. aphanidermatum. After 2 days of incubation, colonies producing clear zones of non-Pythium growth were readily detected. The two bacteria with the largest inhibition zones were identified as Pseudomonas fluorescens. Bush okra emergence(%) in both pot and plastic houses experiments indicated that disease control could be obtained by applying P. fluorescens to the soil or coating the bacteria to the bush okra seeds before sowing. In the plastic houses, application of the bacteria onto Pythium-infested soil and sowing bush okra seeds dressed with bacteria gave 100% emergence. In addition, This was the first reported disease of bush okra by this oomycete in Egypt.

• 원예과학기술지
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• 제34권1호
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• pp.122-133
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• 2016

While ion beams are widely used in plant breeding, little is known about the sensitivity of Lavandula angustifolia (lavender) to ionizing radiation. To compare the biological effects of different types of ionizing radiation on the germination and survival rates of lavender, we exposed lavender seeds to gamma rays, 3 MeV electron beams, and 1.89 MeV proton ion beams. We observed that the seed germination rate decreased with increasing dosages of all three types of ionizing radiation. The malformation rate of lavender seedlings exposed to electron beams and gamma rays increased with increasing radiation dosage. By contrast, the effect of the accelerated proton beams on the malformation rate was negatively correlated with the dosage used. The survival rate of lavender seedlings exposed to the three types of ionizing radiation decreased in a dose-dependent manner. In addition, the survival rate of seedlings irradiated with proton and electron beams decreased more slowly than did that of seedlings irradiated with gamma rays. The half-lethal dose of gamma rays, electron beams, and proton beams was determined to be 48.1 Gy, 134.3 Gy, and 277.8 Gy, respectively, and the most suitable proton-ion energy for lavender seeds in terms of penetration depth was determined to be 5 MeV. These findings provide valuable information for the breeding of lavender by radiation mutation.

• 식물분류학회지
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• 제51권3호
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• pp.181-191
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• 2021

Tulips are bulbous geophytes that have considerable commercial value worldwide. This genus primarily originated in the Tien Shan and Pamir-Alai mountain ranges, which surround the Ferghana Valley. The Ferghana Valley is home to five sections of the genus Tulipa L, represented by 23 taxa (22 species). However, there is a lack of detailed information about the distribution of Tulipa species in the natural geographic area of the Ferghana Valley. Therefore, to address this knowledge gap, we comprehensively investigated the spatial distribution of all Tulipa species in the valley. To assess the spatial distribution, the entire area was divided into 32 squares consisting of four latitudinal and eight longitudinal zones. The results showed that latitudinal zones B and C with 15 and 13 taxa, respectively, along with five longitudinal zones (A5, B3, B4, C2, and C3) with 5 to 10 taxa were hotspots for this genus. Additionally, the spatial distributions of the species in terms of the corresponding state borders, mountain ranges, endemism, and conservation issues were assessed. The findings of this study provide comprehensive information about the distribution of Tulipa species to assist with conservation initiatives ultimately to ensure the survival of various species.

• Journal of Plant Biotechnology
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• 제48권4호
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• pp.255-263
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• 2021

Paederia foetida L. is an important medicinal plant that has been used for the treatment of various gastrointestinal related ailments by different tribal communities in India. This plant is also known for its use as a food. Due to overexploitation, P. foetida has been classified as a vulnerable plant in some states of India. The propagation of P. foetida by conventional methods is easy but very slow. Synthetic seed technology offers incredible potential for in vitro propagation of threatened and commercially valuable plants, and can also facilitate the storage and exchange of axenic plant material between laboratories. However, synthetic seed production for P. foetida has not yet been reported. Thus, to the best of our knowledge, the present study is the first attempt to produce synthetic seeds of P. foetida by calcium alginate encapsulation of in vitro regenerated axenic nodal segments. Sodium alginate (3%) and CaCl₂ (100 mM) were found to be the optimal materials for the preparation of ideal synthetic seeds, both in terms of morphology and germination ability. The synthetic seeds showed the best germination (formation of both shoot as well as root; 83.3%) on ½ MS medium augmented with 0.5 mg/L indole-3-acetic acid. The plantlets obtained from these synthetic seeds could be successfully acclimatized under field conditions. We also studied the storage of these synthetic seeds at low temperature and their subsequent sprouting/germination. The seeds showed a germination rate of 63.3% even after 21 days of storage at 4 ℃; thus, they could be useful for transfer and exchange of P. foetida germplasm.

• Journal of Forest and Environmental Science
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• 제35권1호
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• pp.6-24
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• 2019

We have investigated the impact of anthropogenic and natural disturbances on regeneration, composition and diversity in some temperate forests of Bhagirathi Catchment Area of Garhwal Himalaya. The forests were categorized on the basis of canopy cover and magnitude of disturbance into highly, moderately and least disturbed classes. The dominant tree species at lower elevation were Pinus roxburghii and Quercus leucotrichophora, while Abies pindrow, Q. semecarpifolia and Rhododenron arboreum were the dominant species at the upper elevational forests. Cythula tomentosa and Indegophera heterentha were the dominant shrub species present in all the forests. Similarly, Circium wallichii and Oxalis corniculata were the dominant herb species found in all forests (except Q. leucotrichophora forest), whereas Thalictrum foliolosum and Viola pilosa were noticed in each forest (except P. roxburghii forest). The tree density values oscillated between $400{\pm}10\;trees\;ha^{-1}$ to $750{\pm}89.1\;trees\;ha^{-1}$ which generally decreased from lower to higher disturbance regimes however, the total basal cover value was highest ($88.1{\pm}23.6m^2\;ha^{-1}$) in highly disturbed forest and lowest ($25.8{\pm}2.2m^2\;ha^{-1}$) in moderately disturbed forest. The shrub and herb densities were maximum in least disturbed forest, while the young regenerating individuals i.e., sapling and seedling were observed increasing from high to low disturbed forests which reflected that the forest fragmentation adversely affected the regeneration. However, A. pindrow and P. roxburghii were found invariably encroaching the habitats of R. arboreum and Q. leucotrichophora at various altitudes, respectively. The Canonical Correspondence Analysis clearly indicated that the elevation and lopping intensity have more impact on trees, while shrub and herbs were more influenced by elevation, canopy cover, light attenuation and soil erosion. Pinus roxburghii was the only species which was affected by heavy litter removal and forest fire.