Making an Indian traditional rice variety Mahsuri, bacterial blight resistant using marker-assisted selection     

Lalitha Devi Guvvala  Pranitha Koradi  Vinay Shenoy  Lalitha Shanti Marella 《Journal of Crop Science and Biotechnology》2013,16(2):111-121

Mahsuri a popular traditional variety and the first rain-fed mega variety of the Indian sub- continent. It is highly susceptible to bacterial leaf blight caused by Xanthomonas oryzae pv.oryzae. Nine best performing families of Mahsuri pyramid containing four bacterial blight resistance genes (Xa4, xa5, xa13 and Xa21) were evaluated for agronomic, yield and its related characters viz. days to 50% flowering, plant height, number of tillers, panicle length, filled grains per panicle, grain weight, and yield under natural and disease pressure conditions for three consecutive wet seasons. In addition these pyramids were also evaluated for three different spacings to find out the optimum spacing under disease free and disease pressure conditions. Results revealed that under disease free conditions there was no significant difference between the pyramids and the parent for the characters evaluated in each spacing. However characters plant height, number of tillers, panicle length, filled grains per panicle, yield per plant and yield per sq. m. showed significant variation between the different spacings across seasons. Under heavy disease pressure the parent exhibited highly susceptible reaction whereas the pyramid families were highly resistant. A wider spacing had less yield loss when compared to dense planting under BB infestation in case of parent. There was no such yield loss in the pyramid families. When yield per sq. m. was taken into consideration the 20 × 20 cm spacing showed the highest yield when compared to the other two spacings since number of plants were more. The pyramids insulated the yield loss against bacterial leaf blight and are a gain to the farmers to help overcome the heavy yield losses due to this disease. These pyramids have the potential to replace the parent and can be used directly. In addition they can be used as donors for bacterial blight resistance in any breeding program.  相似文献   

Plant diversity, population structure, and regeneration status in disturbed tropical forests in Assam, northeast India     

Gitamani Dutta  Ashalata Devi 《林业研究》2013,24(4):715-720

We investigated the plant population structure and the phy-tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Fo...  相似文献   

Evaluation of conservation interventions using a cellular automata-Markov model   总被引：1，自引：0，他引：1  

Pinki Mondal  Jane Southworth 《Forest Ecology and Management》2010

The field of biodiversity conservation increasingly recognizes the need for empirical evaluations of conservation interventions. While the amount of money invested into conservation and the number of protected areas across the globe have been increasing in the past few decades, few well-designed empirical studies try to show what could have happened in the absence of the conservation efforts. In this paper, we propose an empirical method to evaluate such conservation intervention. We integrate a cellular automata-Markov modeling approach and a counterfactual approach showing what may have happened in the absence of a certain conservation intervention. We test this method in a human-dominated tropical landscape in Central India; however, our method is transferable to any other socio-ecological setting. The study area is located in the tropical forests of Central India and has witnessed several management strategies since its declaration as a protected area in the mid-1970s. However, landscape practitioners have identified the revised forest policy of 1988 to play a vital role in this landscape. We chose this particular forest policy as the conservation intervention in our study and tested our method using this landscape as a template. We used remote sensing and GIS techniques to analyze multi-sensor satellite data from the last 30 years to monitor forest transitions and compare them with the counterfactual scenario. Our findings not only shed light on the importance of national-level policies in governing forest dynamics, but also established our proposed method as an effective tool for empirical evaluation of conservation intervention, particularly in developing countries.  相似文献   

Relative efficacy of strobilurin formulations in the control of downy mildew of sunflower     

J. Sudisha  S. R. Niranjana  S. L. Sukanya  R. Girijamba  N. Lakshmi Devi  H. Shekar Shetty 《Journal of pest science》2010,83(4):461-470

The efficacy of three commercial formulations of strobilurins, viz., trifloxystrobin, kresoxim-methyl, and azoxystrobin was evaluated against sunflower downy mildew disease caused by Plasmopara halstedii under laboratory, greenhouse, and field conditions. Complete inhibition of sporangial sporulation, zoospore release, and motility was observed with 2 μg ml⁻¹ in trifloxystrobin, and 5 μg ml⁻¹ for azoxystrobin and kresoxim-methyl. Seed treatment with different concentrations of strobilurins enhanced seed germination and seedling vigor of sunflower to varying degrees compared to control. Highest seed germination was recorded at 10 μg ml⁻¹ in kresoxim-methyl, and maximum seedling vigor was noticed with trifloxystrobin at 30 μg ml⁻¹. The effect of strobilurins was tested as seed treatment, foliar application, and seed treatment followed by foliar application. Under greenhouse conditions none of the concentrations used, either as seed treatment and foliar application, were phytotoxic. For the three strobilurins, the seed treatment along with foliar application enhanced the protection of the plants as compared to only the treatment of seeds. Foliar spray treatments alone provided an intermediate control of the disease. Trifloxystrobin showed a better effect than kresoxim-methyl and azoxystrobin. Disease curative activity of trifloxystrobin was higher compared to kresoxim-methyl and azoxystrobin. Tested fungicides when applied on adaxial leaf surface showed partial translaminar activity, and disease inhibition was marginal. Loss of trifloxystrobin and azoxystrobin activity over time was low, indicating stable rainfastness residual activity. A trend in protection against downy mildew disease similar to greenhouse results was evident in the field trials. This is the first report of strobilurins exhibiting high activity against P. halstedii and is a promising fungicide for controlling sunflower downy mildew disease by seed treatment and foliar spray.  相似文献   

Sarcoptic mange infestation in pigs in a hilly region of Meghalaya     

Das  M.  Laha  R.  Devi  P.  Bordoloi  R. K.  Naskar  S. 《Tropical animal health and production》2010,42(5):1009-1011

Skin lesions were collected from 15 adult crossbred pigs maintained at the pig farm of ICAR Research Complex for the North-Eastern Hill Region, Umiam, a hilly region of the state of Meghalaya, India. Skin scrapings of these 15 animals were examined by KOH digestion method. Presence of mites were detected in five animals which were indistinguishable from Sarcoptes scabiei var. suis. Infected pigs were treated with a single dose of Ivermectin at 200 ug/kg body weight, subcutaneously. No mites were recovered from treated pigs after a period of 10 days of post-treatment. The presence of S. scabiei var. suis in pigs from this part of the country has never been reported. This infestation has great significance because it affects the growth rate and feed conversion significantly, specially to the grower and weaned pigs. It can be concluded that S. scabiei var. suis infestation is prevalent in hilly region of Meghalaya. The pig producers are generally unaware about the severity of the problem of mite infestation, so precaution should be taken to prevent their valuable pigs from S. scabiei var. suis infestation.  相似文献   

Assessment of the suitability of Tinopal as an enhancing adjuvant in formulations of the insect pathogenic fungus Beauveria bassiana (Bals.) Vuillemin     

Reddy NP  A Khan PA  Devi KU  Victor JS  Sharma HC 《Pest management science》2008,64(9):909-915

BACKGROUND: Biopesticides based on Beauveria bassiana (Bals.) Vuillemin hold great promise for the management of a wide range of insect pests. The conidia in the biopesticide formulation require an adjuvant to protect them from photoinactivation by sunlight. The suitability of Tinopal, an optical brightener used as sunscreen for baculovirus formulations, for use with B. bassiana was assessed. The aim was to study the effect of Tinopal on the growth and photoprotection of B. bassiana, and its effect on the susceptibility of insects to B. bassiana. RESULTS: Tinopal was found to have no adverse effect on the growth of B. bassiana. It was found to confer total protection (approximately 95% conidial germination at 10 g Tinopal L(-1)) from sunlight up to 3 h of exposure, and a better survival rate than controls even up to 4 h. Helicoverpa armigera Hübner larvae fed on diet with 5 g kg(-1) Tinopal were found to have reduced growth. The duration of the larval stage increased by 3-4 days in 1 and 5 g kg(-1) Tinopal treatments. Among the moths that emerged from larvae fed on diet with 5 g kg(-1) Tinopal, a significantly high number were malformed compared with controls. The larvae that were fed diet with Tinopal showed quicker and higher mortality and required a lower effective lethal dose (LC(50)) than the controls. Tinopal was found to have a synergistic effect with B. bassiana in causing insect mortality. CONCLUSIONS: Tinopal was found to be a suitable adjuvant for B. bassiana-based biopesticide formulations. It conferred tolerance to sunlight and caused stress in the insect, leading to a synergistic effect with B. bassiana.  相似文献   

Potential role of endogeic earthworm <Emphasis Type="Italic">Pontoscolex corethrurus</Emphasis> in remediating banana blood disease: a preliminary observation     

Suk-Kuan?Teng  Nor?Azwady?Abd.?AzizEmail author  Muskhazli?Mustafa  Rozeita?Laboh  Intan?Safinar?Ismail  Sujithra?Devi 《European journal of plant pathology / European Foundation for Plant Pathology》2016,145(2):321-330

Blood disease is a destructive bacterial infection that causes severe yield loss to the banana industry. Ideally, an environmental friendly yet practical approach is necessitated in the search for effective treatment against the disease. Endogeic earthworms are soil biota that help in improving soil physico-chemical and biological properties and thuspromote plant health. The present study assessed the effect of Pontoscolex corethrurus on banana infected by blood disease. The effect of earthworms was evaluated through observations on stem and root morphology, anatomy and total phenolic contents (TPC). P. corethrurus was inoculated into polybags planted with banana plantlets; inoculation of blood disease bacterium (BDB) into the roots of the plantlets was done using a drenching method. Stem and root sections of the plantlets were preserved in FAA for histological study upon harvest. The remaining sections were freeze-dried for TPC analysis. Root sections of plantlets infected with BDB showed lower root biomass compared to the control and earthworm-inoculated plantlets. Observations under microscope also showed that tissue necrosis at the vascular bundles of infected roots were more severe compared to the earthworm-inoculated and unaffected plantlets. Plantlets inoculated with earthworms had the highest root TPC, followed by the unaffected plantlets and plantlets infected with BDB. Although infected plantlets with earthworm inoculation showed disease symptoms, the disease severity was slightly less. The results suggested the potential role of P. corethrurus in improving plant health for disease management and sustainable agriculture.  相似文献   

Development and Identification of Novel Rice Blast Resistant Sources and Their Characterization Using Molecular Markers     

J. S. Rama Devi S.  Singh Kuldeep  Umakanth B.  Vishalakshi B.  Renuka P.  Vijay Sudhakar K.  S. Prasad M.  C. Viraktamath B.  Ravindra Babu V.  S. Madhav M. 《水稻科学》2015,22(6):300

To develop and characterize introgression lines for leaf and neck blast resistance, 326 introgression lines were developed using various accessions of six different AA genome wild species in the genetic background of elite Indian varieties like PR114 and Pusa 44 and were screened for blast resistance. Stringent phenotyping coupled with genotyping using gene based markers led to the identification of four resistant introgression lines, which showed promising resistance and do not possess any of the tested genes. Furthermore, multi-location screening confirmed the field resistance of the four introgression lines to both leaf and neck blast. Molecular characterization of these introgression lines using genome-wide simple sequence repeat markers revealed the presence of small percentage of wild Oryza genome introgrssion. So these lines can be used for mapping and identification of novel leaf and neck blast resistance genes. Thus, these four introgression lines can be considered as new genetic resources for blast resistance.  相似文献   

Dual‐treatment autodissemination station with enhanced transfer of an insect growth regulator to mosquito oviposition sites     

Yi Wang  Devi S. Suman  Jacques Bertrand  Limin Dong  Randy Gaugler 《Pest management science》2014,70(8):1299-1304

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Quality Compost Production from Municipality Biowaste in Mix with Rice Straw,Cow Dung,and Earthworm Eisenia fetida     

Shantibala Devi Sanasam 《Compost science & utilization》2017,25(3):141-151

The biodegradable portion of city waste is a potential source of plant nutrients, and appropriate techniques of composting can convert it to quality compost with higher nutrient content and lower levels of pathogenic microorganisms. An amount of 68.19 tons of waste is generated in Imphal City, Manipur, India, of which 24.84 tons were biodegradable. Of the total biodegradable municipality waste (MW), 20.7 tons were produced in households and the vegetable markets of the city. The MW were found to contain pathogenic bacteria (PB), namely, Salmonella spp., Shigella spp., Micrococcus spp., and Enterobacter spp. in the range of 6.35–9.28 (log cfu/g dry biomass), and agriculturally beneficial bacteria (BB), namely, phosphate solubilizers, Azospirillum spp., Azotobacter spp., and cellulose degraders in the range of 6.25–8.83 log cfu/g dry biomass. Pre-treatment of the MW by exposure at temperatures of 27°C–50°C in a greenhouse for 5 days could not reduce the level of PB and BB, but by heating at 100°C for 8 h followed by 30°C for 16 h of a day for three consecutive days, the PB (except Micrococcus spp.) could be eliminated. Aerobic composting of the mixture of MW with cow dung (CD) and rice straw (RS) and by inoculation with epigeic earthworm Eisenia fetida, produced high quality manure as evident from more finer particle (56.6%), higher nutrient (2.19% N) content, higher population of BB (7.03–9.19 log cfu/g dry biomass), and reduced level of PB (6.87–8.09 log cfu/g dry biomass).  相似文献