• Title/Summary/Keyword: Abiotic factors.

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Effect of rearing season, host plants and their interaction on economical traits of tropical tasar silkworm, Antheraea mylitta Drury- an overview

  • Bhatia, Narendra Kumar;Yousuf, Mohammad
    • International Journal of Industrial Entomology and Biomaterials
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    • v.29 no.1
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    • pp.93-119
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    • 2014
  • Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.

Leveraging Rice Genetic Diversity: Connecting the Genebank to Mainstream Breeding

  • J. Damien Platten
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.31-31
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    • 2022
  • Rice contains a wealth of genetic diversity, both within Oryza sativa and in related A-genome species. Decades of genetic research into this diversity have identified dozens of major genes contributing to a wide variety of important traits, including disease resistance, abiotic stress tolerance (drought, salinity, submergence, heat, cold etc.), grain quality, flowering date and maturity and plant architecture. Yet despite these opportunities, very few of the major genes and QTLs known have been successfully applied through rice breeding programs to produce sustained changes in farmer's fields. This presentation will briefly examine some of the factors limiting application of major genes in the mainstream breeding programs, and steps that have been taken to alleviate those limitations. As a result of these interventions, dozens of major genes that were previously unavailable to breeders are now being used confidently in the variety development process. Case studies will be discussed of genes critical for blast resistance worldwide, rice yellow mottle virus for Africa, and new validated QTLs for salinity tolerance.

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Evaluation of mycelial growth of Lentinula edodes and Ganoderma lucidum originated from South Korea and Brazil

  • Motta, Marcia Araujo;Jang, Jeonghwa;Kim, Mijeong;Choi, Eunsil;Kim, Jiyoung;Torracca-Rocha, Anna Carolina;Kong, Won-Sik;Urban, Arailde Fontes
    • Journal of Mushroom
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    • v.15 no.2
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    • pp.94-97
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    • 2017
  • The choice of strain, substrate, and environmental conditions are fundamental factors that determine the ability of a fungus to develop and produce mushrooms with high quality. The objective of this study was to compare the strains of Lentinula edodes and Ganoderma lucidum originated from South Korea and Brazil in relation to their vegetative development in different culture media, to obtain isolates with high quality. The strains of the two mushroom species from Brazil and South Korea grew slowly, possibly because of abiotic factors or storage technique used. However, it may be concluded that temperature, humidity, light, pH, and nutrients from the substrate, if not regulated appropriately may affect the vegetative species.

Litter Decomposition Process in Coffee Agroforestry Systems

  • Petit-Aldana, Judith;Rahman, Mohammed Mahabubur;Parraguirre-Lezama, Conrado;Infante-Cruz, Angel;Romero-Arenas, Omar
    • Journal of Forest and Environmental Science
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    • v.35 no.2
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    • pp.121-139
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    • 2019
  • Decomposition of litter is a function of various interrelated variables, both biotic and abiotic factors. Litter decomposition acts like a natural fertilizer play a prime role in maintaining the productivity and nutrient cycling in agroforestry systems. There are few studies of decomposition carried out in agroforestry systems with coffee; so it is necessary to perform more research work to fill the research gap, which will allow a better understanding of the management of the coffee agroforestry systems. This paper is based on the theoretical and conceptual aspects of leaf litter decomposition in agroforestry systems, emphasizing the combination with coffee cultivation and critically examined the role of the different factors involved in the decomposition. This study made a comparison of different investigations with regards to weight loss, decomposition rates (k), initial chemical composition, and release of the main nutrients. This study suggested that it is necessary to implement studies of decomposition and mineralization, and the microflora and fauna associated with these processes, so that serves as an important tool to develop a model for enabling a description of the short, medium, and long-term dynamics of soil nutrients in coffee agroforestry systems.

Variability of Stem-Base Infestation and Coexistence of Fusarium spp. Causing Crown Rot of Winter Wheat in Serbia

  • Jevtic, Radivoje;Stosic, Nemanja;Zupunski, Vesna;Lalosevic, Mirjana;Orbovic, Branka
    • The Plant Pathology Journal
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    • v.35 no.6
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    • pp.553-563
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    • 2019
  • Investigations related with factors influencing root and crown rot are rare and mainly related to farming practice and soil management. The main objective of this study was to examine broader range of factors influencing stem-base infestation of winter wheat in the field conditions. The effect of spatial distribution of infected plants on disease index (DIs) assessments was also investigated. Analysis of factors influencing DIs of crown rot of wheat demonstrated significant influence of the growing seasons (P < 0.001) and extreme fluctuations in winter temperatures (P < 0.001). In addition to that, localities together with their interaction with the growing season also significantly influenced DIs (P < 0.001). Aggregation of infected plants influenced variability of DI estimations, and it was pointed out that more extensive investigation should be conducted on broad range of DI in order to establish sampling method giving uniform sampling precision. Fusarium graminearum was shown to be predominant Fusarium species in Serbia (72.6%) using sequence-characterized amplified region analysis. Interestingly F. oxysporum was isolated in higher frequencies (27.4%) than it was reported in the literature. Given that there were no reports on the diversity of Fusarium species causing crown rot of wheat in Serbia, this study presents first report on this important subject. It also indicated that more attention should be focused on combined effects of abiotic and biotic factors influencing stem-base infestation of winter wheat. This knowledge will contribute to better understanding of factors influencing root and crown rot of wheat which would ensure sustainable disease management in the future.

A Field Application Feasibility of Biologically Derived Substances (Naphthoquinone Derivate: NQ 2-0) for the Mitigation of Harmful Cyanobacterial Blooms (유해 남조류 제어를 위한 생물유래 살조물질 Naphthoquinone 유도체 (NQ 2-0)의 현장 적용 가능성)

  • Joo, Jae-Hyoung;Park, Chong-Sung;Choi, Hye Jeong;Lee, Heon Woo;Han, Myung-Soo
    • Ecology and Resilient Infrastructure
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    • v.4 no.3
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    • pp.130-141
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    • 2017
  • We evaluated the field application feasibility that biologically derived substances (Naphthoquinone derivate: NQ 2-0) can be used for the eco-friendly mitigation of natural harmful cyanobacterial blooms in freshwater. We conducted a 30 ton scale mesocosm experiment to investigate the effects of NQ 2-0 on biotic and abiotic factors in water collected from Gi-heung reservoir. In the mesocosm experiments, the abundance of Microcystis sp. was continuously increased in the control. However, the Microcystis sp. cell density was sharply decreased on the $10^{th}$ day. In the treatment, NQ 2-0 showed the strong and selective algicidal activity toward the target cyanobacteria (Microcystis sp.). Accordingly, the algicidal activity of NQ 2-0 compound increased gradually until $10^{th}$, $15^{th}$ days and algal biomass was decreased to 99.4 and 100 %, respectively. NQ 2-0 compound was not only selective algicidal activity but also the growth of other phytoplankton and increased the Shannon-Wiener diversity index of phytoplankton. In the mesocosm experiments, the dynamics of biotic (bacteria, heterotrophic nanoflagellate, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. These results suggest that NQ 2-0 could be a selective and ecologically safe algicide to mitigate harmful cyanobacterial blooms. In addition, it is believed that NQ 2-0 will play a major role in forming a healthy aquatic ecosystem by facilitating habitat and food supply of aquatic organisms.

Environmental Factors and Phragmites Distribution at Various Habitats in Eulsukdo Ecological Park (을숙도 생태공원내 서식지별 환경요인과 갈대분포 특성)

  • Chung, Yong Hyun;Sung, Kijune;Kang, Daeseok;Lee, Suk Mo;Park, Soyoung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.3
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    • pp.50-61
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    • 2008
  • Environmental factors and phragmites growth properties at various habitats in Eulsukdo ecological park were investigated to understand major factors affecting phragmites distribution in constructed wetlands. Although phragmites is very important species in wetland ecosystem, it should be controlled to prevent excessive expansion within the restricted park area. The results showed that phragmites dominant sites have the highest LAI among other emerged plants habitats and could adversely affect for waders habitats. Phragmites were also found at the areas with wide ranges of water-depth than other plants, and showed phragmites could be favored for occupying the newly constructed wetlands like Eulsukdo ecological park. The results showed difference in soil redox potential between phragmites dominant and non-dominant sites. Because soil redox potential is affected by wetland hydrology like flooding duration, control of wetland hydrology should be considered for creation and management of constructed wetlands. The results also showed that differences in soil cation exchange capacity, soil salinity, soil organic matter content and site inclination between phragmites dominant and non-dominant sites as well as brackish and freshwater areas. Those abiotic factors can be important considerations for the sustainable wetland management especially for the phragmitest managements in the ecological park.

Insights into the Gut Microbiota of Freshwater Shrimp and Its Associations with the Surrounding Microbiota and Environmental Factors

  • Zhao, Yanting;Duan, Cuilan;Zhang, Xu-xiang;Chen, Huangen;Ren, Hongqiang;Yin, Ying;Ye, Lin
    • Journal of Microbiology and Biotechnology
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    • v.28 no.6
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    • pp.946-956
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    • 2018
  • The gut microbiota of aquatic animals plays a crucial role in host health through nutrient acquisition and outcompetition of pathogens. In this study, on the basis of the high-throughput sequencing of 16S rRNA gene amplicons, we examined the bacterial communities in the gut of freshwater shrimp (Macrobrachium nipponense) and in their living environments (sediment and pond water) and analyzed the effects of abiotic and biotic factors on the shrimp gut bacterial communities. High bacterial heterogeneity was observed in the freshwater shrimp gut samples, and the result indicated that both the surrounding bacterial community and water quality factors (particularly dissolved oxygen and temperature) could affect the shrimp gut bacterial community. Despite the observed heterogeneity, 57 genera, constituting 38-99% of the total genera in each of the 40 shrimp gut samples, were identified as the main bacterial population in the gut of M. nipponense. In addition, a high diversity and abundance of lactic acid bacteria (26 genera), which could play significant roles in the digestion process in shrimp, were observed in the shrimp gut samples. Overall, this study provides insights into the gut bacterial communities of freshwater shrimp and basic information for shrimp farming regarding the application of probiotics and disease prevention.

Analysis of Site Suitability of Forest Stands for Extracting Sap of Acer pictum var. mono Using GIS and Fuzzy Sets (퍼지집합과 GIS를 이용한 고로쇠나무 임분의 수액채취 적지 분석)

  • Lee, Byungdoo;Chung, Joosang;Kwon, Dae-soon
    • Journal of Korean Society of Forest Science
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    • v.95 no.1
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    • pp.38-44
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    • 2006
  • Using GJS and fuzzy sets, a model was developed for evaluating the site-suitability of forest stands for extracting sap of Acer pictum Thunb. var. mono in Mt. Baekun area. In the model, the productivity of sap extraction was expressed as the function of biotic and abiotic site factors. Among the factors, the topographic terrain conditions and accessibility of forest stands were chosen to consider working environment of the sap extraction. The difference in measurements of the factors between sap-extraction and non-sap-extraction forest stands was used in determining the weight of the relative importance for sap extraction productivity. The weight for distance-to-stream, vegetation type and shading condition turned out relatively higher than those for tree age, distance-to-road and DBH. Based on the results, a site-suitability map in Mt. Baekun area for sap extraction was built.