We conducted the present study to develop a simplified method of isolating gonadal germ cells (GGCs) from embryonic gonads to facilitate the production of germline chimeras in avians. Developing gonads recovered from 7-day-old chick embryos were incubated for 30 minutes to 24 hours at 37.8°C in phosphate-buffered saline without Ca2＋ and Mg2＋ (PBS[－]). GGCs began to be released from gonads after 30 minutes of incubation; the number of GGCs release increased until 12 hours of incubation. The purity of GGCs (the number of GGCs released divided by the total number of cells released) was approximately 50% for the initial 1.5 hours of incubation and decreased thereafter. We stained 50 GGCs in PBS[－] with PHK26 fluorescent dye and injected them into the bloodstream of a 2-day-old chick embryo. GGCs exhibiting fluorescence were detected in the gonads of recipient embryos at 5 days after transfer. These results indicate that hig-purity, highly viable GGCs can be isolated from chick embryos simply by incubating the developing gonads in PBS[－].
Fruit flies such as the Bactrocera dorsalis complex (Diptera:Tephritidae) are serious horticultural pests. In Indonesia—especially in Bogor, West Java—fruit flies are major pests on guava and star fruit, both valuable crops. Synthetic insecticides are popular for fruit fly control. However, their inappropriate use can negatively affect the environment and humans. Methyl eugenol extracted from the leaves of plants such as Melaleuca bracteata and Ocimum sp. as a male fruit fly attractant is an environmentally friendly and consumer-safe alternative for control. We determined the potency of leaf extracts as fruit fly attractants by observing their effectiveness against the most destructive fruit flies (B. dorsalis complex) in guava and star fruit orchard, therefore identification to both species is needed. Seven attractants were tested for trapping fruit flies: essential oils of M. bracteata and Ocimum sp., along with each residual distillation water, mash extracts of each species, and commercial methyl eugenol as a control. Both essential oils showed high potential as fruit fly attractants. For more than 2 weeks they attracted male fruit flies in guava and star fruit orchards as effectively as commercial methyl eugenol. Distillation water and mash extracts from the leaves of both plants lasted for a maximum of 6 days. In a guava orchard, M. bracteata and Ocimum sp. essential oils and the control trapped 78.75, 77.5, and 88.75 fruit flies, respectively, over 2 weeks, and in a star fruit orchard they trapped 35.75, 38.75, and 40.50, respectively. Capture rates using distillation water and mash extracts from both plants were significantly lower than those using essential oils in both orchards. In the guava orchard 57.14% of the fruit flies trapped were B. papayae and 42.85% B. carambolae (n＝70); in the star fruit orchard, 45.71% were B. papayae and 54.28% were B. carambolae (n＝70).
Agricultural economic development strongly relies on the health of pollinators including honeybees. Honeybee health is afflicted by multiple risk factors such as toxicity from pesticide application, shortage of floral resources, climate change, reduction in genetic diversity and diseases caused by various pathogenic bacteria, fungi and viruses. Controlling disease is necessary for maintaining honeybee health and this will benefit both agricultural and apicultural industries. As other insects and animals, honeybees possess a diverse set of individual or colony level disease defense mechanisms. One route by which honeybees combat diseases is through the shielding effects of gastrointestinal bacteria. Except for some transient bacteria, a set of consistent and distinctive phylotypes of bacteria colonize honeybee digestive tracts. The beneficial bacterial communities inhabiting honeybee guts play key roles in maintaining honeybee health not only by participating in nutrient processing but also by enhancing the immune system, and inhibiting the growth of pathogenic organisms with metabolic products or obstruction of pathogen colonization. Therefore, a symbiotic microbial balance in the honeybee digestive tract is critical for protecting honeybees from disease and other risks. Many researchers have emphasized the beneficial roles of gastrointestinal bacteria in sustaining honeybee health and suggest their contributions to development of novel and sustainable disease control strategies.
Edible landscaping (EL) in the Philippines is an innovative concept of combining various principles of landscape design with existing technologies for small-scale crop production. EL utilizes vegetables, herbs, and fruit crops as major softscape materials to substitute for the ornamental plants commonly used in conventional landscaping. It considers the aesthetics and functionality of space in relation to the production of safe and readily available crop products for the family and community. EL involves various components such as softscape, hardscape, design, and crop production. The design part of EL is very flexible and can vary from one cropping period to another, depending on the planting scheme chosen. Edible crops can assume several landscape functions to create different attractions in each cropping season. The production side of EL follows recommended techniques for seedling establishment up to harvesting while some practices are modified to fit the chosen design. EL also promotes the use of organic pest management and recycling of available on-site resources—particularly those derived from plant residues—to enhance and maintain soil productivity. Even though EL is focused on food availability at household level, it is also intended to increase interest in the utilization of endemic edible plants and greening of urban spaces to alleviate environmental problems. Moreover, surplus crop products can be marketed to generate additional income. Currently, EL is being intensively promoted in the Philippines and is open for further development to cater for a wider scope of crop production.
Fruit flies are among the most economically important pests in crop production and the highly invasive Bactrocera invadens has rapidly spread across sub-Saharan Africa in recent years. In 2008, Swaziland initiated a national fruit fly surveillance programme to facilitate continued trade with export partners and to develop an early detection and monitoring system for invasive fruit fly species. Fruit fly traps were set up at major border posts, markets and agricultural estates where target host plants of B. invadens are grown. Traps baited with Methyl eugenol, Trimedlure and Cuelure were placed in agricultural estates while only traps with Methyl eugenol were placed at markets and border posts. Fourteen species, dominated by Ceratitis capitata (40.2%), C. rosa (22.7%) and Dacus bivittatus (32.7%) were collected from agricultural estates. There were significant differences in the number of flies trapped per day per trap between lures (p>0.05) and estates (p=0.0204). Only 9 species, dominated by C. rosa, (76.35%) were collected from border posts and markets. There were significant differences in the number of flies trapped between border gates (p>0.05) and none were trapped from the national marketing board. No species of phytosanitary concern were trapped during the survey. However, the country remains vulnerable to invasion by B. invadens due to its reported presence or increased sightings in neighbouring countries. This emphasises the need for continued surveillance to ensure early detection of invasive species, which would enhance the country’s ability to influence the chances of invasive species establishment and spread.
In Thailand, Nakhon Pathom, Samut Sakhon, and Ratchaburi provinces, which are in the central region of the country, are the largest areas for guava cultivation. Kimju and Pansithong are the most extensively grown cultivars, and they have been seriously damaged by two species of root-knot nematodes, Meloidogyne incognita and M. enterolobii (or M. mayaguensis). The latter species was only recently reported in Thailand but is common in China, Brazil, and the United States. Substantial numbers of guava trees are in decline and show reduced fruit production. In this survey study of six guava orchards in central Thailand, we found that common aboveground symptoms of nematode infection included yellowing, stunting, folded leaves, blighted and wilted leaves (especially when water was lacking), and slow ripening of fruits. Underground symptoms included root galls, partially rotted roots, and, in some cases, prolific production of adventitious roots to compensate for damaged and nonfunctional roots. When we examined the morphometric characteristics of second-stage juveniles of M. incognita and M. enterolobii obtained from soil around guava plants, we observed no significant correlation between the characteristics of the two species or between the characteristics of populations within each species (P>0.05). For the biological control of root-knot nematodes in guava, we evaluated a commercially available fungal agent, Trichoderma harzianum, which effectively controls several other soil-borne pathogens and has been shown to induce disease resistance and stimulate adventitious root growth in plants. We found that inoculation of the root zones of guava plants with T. harzianum reduced the number of nematodes in both soil and roots as compared to the number in untreated plants (P<0.05). Moreover, inoculation of guava plants with T. harzianum arrested the development of the juvenile nematodes (P<0.05). Trichoderma harzianum is less expensive than chemical control agents and poses no risk to the environment.
Agriculture in Egypt mostly depends on crop production in the Nile Delta, but problems of salinization in the surface soil become obvious due to development of Aswan High dam and irrigation agriculture. In this situation, rice cultivation is considered as a salt leaching method because it uses larger amounts of water than field crops. The present study was conducted to investigate the effects of previous rice cropping history on salt accumulation of surface soils on 15 farms in the middle Nile Delta. These surface soil samples were collected from the Agriculture Research Center (ARC) near Sakha and 14 private farms near ARC, and categorized by the record of previous rice cropping history. In addition, farmers were asked about the field conditions, such as fertilization and subsurface drainage. Irrigation water was also sampled in each area. As results of soil analysis, there were little differences in pH, total carbon (T-C), total nitrogen (T-N), and cation exchange capacity (CEC) of the soil samples, showing the basic properties of soils were similar. However, exchangeable bases showed some differences, and electrical conductivity (EC) and exchangeable Na＋ revealed correlations, but these differences were not related to previous rice cropping history. Ion concentrations in irrigation water were also different among areas. Based on statistical results, there were significant differences in salt accumulation of surface soils depending on area and especially in the conditions of subsurface drainage. However, previous rice cropping was seen to have had little effect on salt accumulation in the surface soils. These results show that other factors, such as subsurface drainage conditions or quality of irrigation water, affect soil salinity in these study sites rather than rice cultivation.
The objective of this study was to clarify the effect of temperature during initial ripening stage and assimilation in chalky rice grain. Japonica rice cultivars: Fusaotome, Fusakogane, Akitakomachi, Haenuki, Sasanishiki, and Koshihikari, showed different percentages in the occurrence of chalky rice grain under high temperatures during the initial ripening stage. The above Japonica rice cultivars were used to clarify the order of all grains within a panicle, and investigate rice grain weight and rice quality at different spikelet positions. Significant negative correlation between the flowering date and rice grain weight in all cultivars suggests that rice grain weight is affected by the length of the ripening period. There was also a significant positive correlation between the percentage of chalky rice grain and the days from heading to flowering in Haenuki and Sasanishiki cultivars. However, a significant negative correlation was found between the percentage of chalky rice grain and days from heading to flowering in Fusaotome, Fusakogane and Akitakomachi. In addition, the daily average temperature during initial ripening stage in Fusaotome, Fusakogane and Akitakomachi was higher than the other cultivars. These results suggest that the days from heading to flowering within a panicle and high temperature at initial ripening period cause the occurrence of chalky rice grain.
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