A gravimetric method for determining the relative volatilities of non-aqueous pesticide formulations and spray diluents     

Alam Sundaram 《Pest management science》1985,16(4):397-403

A simple gravimetric method was developed for determining the relative volatilities of non-aqueous pesticide formulations and spray diluents, and was compared with the droplet method. The technique involved evaporation of a liquid film from a filter paper surface, and provided greater precision than the droplet method. With both methods, the percentage of mass or volume remaining at time t followed an exponential decay curve, and the coefficients of the equations showed a good correlation between the two methods. The rates of evaporation were consistently lower in the gravimetric method than in the droplet method, and because of this, subtle differences in the relative volatilities of different formulations could be identified by the gravimetric method but not by the droplet method.  相似文献   

Incidence of Paracooperia matoffi (Matoff, 1938) Le Roux, 1950 in Indian buffaloes     

R K Sundaram  M S Sivasubramaniyam  R P Iyer  C T Peter 《The Indian veterinary journal》1968,45(1):22-31

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Assessment of canopy and ground deposits of fenitrothion following aerial and ground application in a northern ontario forest     

Kanth M. S. Sundaram  Rhonda Millikin  Alam Sundaram 《Pest management science》1989,25(1):59-69

Spray deposit patterns on simulated and live foliage of balsam fir and white birch were determined at different heights and at periphery and interior locations of the tree crown, following aerial and ground applications of fenitrothion formulations over a boreal forest near Searchmont, Ontario. Droplet size spectra and AI deposits were assessed at ground level with ‘Kromekote’ card/glass plate units. Aerial application was made with a Cessna 188 aircraft fitted with ‘Micronair’ AU3000 atomizers. For ground application, a ‘Soloport’ 423 backpack mistblower fitted with an extension tube and a diffuser nozzle at the tip was used. Deposit data on the ground samplers indicated significantly larger droplets and greater deposits from the aerial spray trial than from the mistblower treatment. However, foliar deposits at tree canopy level were only slightly higher in the former trial than in the latter. Analysis of spray deposits on simulated and live fir foliage showed definite gradients in deposit levels, decreasing from top to bottom crown, and from periphery to inner tree crown. In the birch tree crown, such gradients were not observed. The simulated leaves generally acted as better collectors of spray droplets than the natural leaves. The overall mean deposit values, expressed in ng cm^?2, showed a wide variation, although there was generally a close relationship between the deposits on the simulated and natural surfaces.  相似文献   

Initial deposits and persistence of azadirachtin in fir and oak foliage after spray application of ‘Margosan-O’® formulation     

Kanth M. S. Sundaram  Johanna Curry 《Pest management science》1994,41(2):129-138

Foliar deposits and persistence of azadirachtin were investigated after spraying ‘Margosan-O’® formulation at three dosage and volume rates on to balsam fir and oak seedlings in a laboratory chamber. Droplet-size spectra and deposits were assessed using artificial samplers, and foliar residues were measured by high-performance liquid chromatography (HPLC) at different intervals of time after treatment. Disappearance of azadirachtin from both types of foliage was rapid, and the DT₅₀ (the time required for 50% of the initial concentration to disappear) values ranged from 17 to 22 h. The initial azadirachtin concentrations varied widely from 4 to 96 μg g^?1 (fresh weight), but the rate constants 0.0311 to 0.0414, were not significantly different. The data thus indicated a poor relationship between initial concentrations and the rate of loss. The influence of spray droplet size and cuticular wax content of foliage on persistence of azadirachtin was investigated using both foliar types, and glass microscope slides without and with the foliar wax coating. Neither the type of surface nor the droplet size influenced the persistence. The rate of azadirachtin loss from the glass slides was faster than from both types of foliage, and was unaffected by the presence of wax coating. The fir foliage had higher cuticular wax content than the oak foliage, but the persistance of azadirachtin was similar in both foliar types.  相似文献   

Marker assisted introgression of bacterial blight resistance in Samba Mahsuri,an elite indica rice variety   总被引：1，自引：1，他引：0  

Raman M. Sundaram  Manne R. Vishnupriya  Sunil K. Biradar  Gouri S. Laha  Gajjala Ashok Reddy  N. Shobha  Rani  Nukala P. Sarma  Ramesh Venkata Sonti 《Euphytica》2008,160(3):411-422

Samba Mahsuri (BPT5204) is a medium slender grain indica rice variety that is very popular with farmers and consumers across India because of its high yield and excellent cooking quality. However, the variety is susceptible to several diseases and pests, including bacterial blight (BB). We have used PCR based molecular markers in a backcross-breeding program to introgress three major BB resistance genes (Xa21, xa13 and xa5) into Samba Mahsuri from a donor line (SS1113) in which all the three genes are present in a homozygous condition. At each backcross generation, markers closely linked to the three genes were used to select plants possessing these resistance genes (foreground selection) and microsatellite markers polymorphic between donor and recurrent parent were used to select plants that have maximum contribution from the recurrent parent genome (background selection). A selected BC₄F₁ plant was selfed to generate homozygous BC₄F₂ plants with different combinations of BB resistance genes. The three-gene pyramid and two-gene pyramid lines exhibited high levels of resistance against the BB pathogen. Under conditions of BB infection, the three-gene pyramid lines exhibited a significant yield advantage over Samba Mahsuri. Most importantly, these lines retain the excellent grain and cooking qualities of Samba Mahsuri without compromising the yield as determined in multi-location trials. This work demonstrates the successful application of marker-assisted selection for targeted introgression of multiple resistance genes into a premium quality rice variety. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. R. M. Sundaram and M. R. Vishnupriya have contributed equally to this work.  相似文献   

Identification of informative SSR markers capable of distinguishing hybrid rice parental lines and their utilization in seed purity assessment   总被引：4，自引：0，他引：4  

R. M. Sundaram  B. Naveenkumar  S. K. Biradar  S. M. Balachandran  B. Mishra  M. IlyasAhmed  B. C. Viraktamath  M. S. Ramesha  N. P. Sarma 《Euphytica》2008,163(2):215-224

With the objective of identifying SSR markers that can distinguish parental lines of rice hybrids, we characterized 10 each of cytoplasmic male sterile (CMS) and restorer (R) lines along with 10 popular Indian rice varieties using a set of 48 hyperpolymorphic SSRs distributed uniformly across the rice genome. All the SSR markers were polymorphic, amplifying a total of 163 alleles, with an average of 3.36 ± 1.3 allelic variants per locus. Twenty-seven SSR markers showed amplification of an allele, which was very specific and unique to a particular parental line and not amplified in any other rice genotype tested. Through multiplex PCR, SSR marker combinations that were unique to a particular parental line or hybrid were also identified. With a set of 10 SSR markers, all the public bred Indian rice hybrids along with their parental lines could be clearly distinguished. To utilize these SSR markers effectively for detection of impurities in parental lines, a two dimensional bulked DNA sampling strategy involving a 20 × 20 grow-out matrix has been designed and used for detection of contaminants in a seed-lot of the popular CMS line IR58025A. We have also designed a multiplex PCR strategy involving single tube analysis using 2–3 markers for hybrid seed purity assessments and demonstrate its superiority over single marker analysis in accurate detection of impurities in hybrids. Implications of parental and hybrid specific SSR markers and strategies to utilize the informative SSR markers for detection of contaminants in a cost effective manner are discussed.  相似文献   

Isolation, enumeration, and characterization of diazotrophic bacteria from paddy soil sample under long-term fertilizer management experiment     

Rashedul Islam  Pankaj Trivedi  Munusamy Madhaiyan  Sundaram Seshadri  Gillseung Lee  Jinchul Yang  Yoohak Kim  Myungsook Kim  Gwanghyun Han  Puneet Singh Chauhan  Tongmin Sa 《Biology and Fertility of Soils》2010,46(3):261-269

A study was undertaken to determine the free-living culturable diazotrophic bacteria of paddy soils from a long-term fertilizer management experiment. Long-term application of different fertilizers significantly affected the population of free-living diazotrophs. Out of 165 distinct bacterial morphotypes observed during the isolation process, only 32 were positive for both acetylene reduction assay (ARA), and nifH gene screening. The ARA activity of the isolates ranged from 1.8 to 2,844.7 nmol ethylene h^?1 mg protein^?1. The 16S rRNA analysis identified the isolates to be members of 13 different genera viz. Bacillus, Pseudomonas, Paenibacillus, Serratia, Ochrobactrum, Lysinibacillus, Burkholderia, Brevundimonas, Herbaspirillum, Novosphingobium, Sphingomonas, Xanthomonas, and Azorhizobium. Though partial nifH gene sequencing of diazotrophic isolates showed good consistency with that of 16S rRNA-based identification, some nifH sequences were similar to a variety of uncultured nitrogen-fixing bacteria. The diversity of free-living diazotrophic bacteria and the wide distribution of nifH sequences indicate the potential contribution of these microorganisms to nitrogen input to paddy fields.  相似文献   

Prediction of heterosis for grain yield in rice using 'key' informative EST-SSR markers     

I. Jaikishan  P. Rajendrakumar  M. S. Ramesha    B. C. Viraktamath    S. M. Balachandran    C. N. Neeraja    K. Sujatha    K. Srinivasa Rao  P. Natarajkumar    Y. Hari    K. Sakthivel    A. S. Ramaprasad    R. M. Sundaram 《Plant Breeding》2010,129(1):108-111

This study was undertaken to assess the comparative potential of 25 Expressed Sequence Tag derived simple sequence repeats (EST-SSRs) and 25 genomic SSRs in the prediction of grain yield heterosis using a set of nine cytoplasmic male sterile (CMS) lines and 32 restorer lines of rice. EST-SSRs and genomic SSRs exhibited an average Polymorphism Information Content value of 0.37 and 0.45, respectively. The coefficient of marker polymorphism among parental lines with respect to a set of hypervariable EST and genomic SSRs was correlated with standard heterosis for grain yield of six public bred rice hybrids. EST-SSRs gave a better correlation (r = 0.75) as compared with genomic SSRs (r = 0.09). When 10 'key' informative EST-SSR markers which showed a higher positive correlation with grain yield heterosis were validated in a new set of 14 experimental hybrids, the markers exhibited a higher correlation (r = 0.79), indicating the predictive value of these EST-SSRs. We recommend these 10 'key' informative EST-SSR markers for analysis of genetic diversity of parental lines and prediction of heterosis in hybrid rice breeding programmes.  相似文献   

Protective efficacy of active compounds from Phyllanthus amarus against white spot syndrome virus in freshwater crab (Paratelphusa hydrodomous)          下载免费PDF全文

Dinesh Sundaram  Karthikeyan Kesavan  Hemalatha Kumaravel  Roohi Fatima Mohammed  Mekata Tohru  Itami Toshiaki  Sudhakaran Raja 《Aquaculture Research》2016,47(7):2061-2067

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Comparative analysis of bioremediation potential of adapted and non-adapted fungi on azo dye containing textile effluent     

Rajendran R  Karthik Sundaram S  Prabhavathi P  Sridevi BV  Gopi V 《Pakistan journal of biological sciences: PJBS》2011,14(11):610-618

About 4 different predominant adapted fungal strains (screened from effluent sample) Aspergillus sp., Penicillium sp., Fusarium sp. and Mucor sp. and 4 predominant non-adapted strains (screened from soil, water and fungal fruiting bodies) Aspergillus sp., Penicillium sp., Fusarium sp. and Rhizopus sp., with potential dye decolorization ability on Reactive black 5, Amido black-10B, Red 5B, Reactive red 120 and Anthraquinone violet R were isolated. These organisms were used to develop a consortium which was used in analyzing the bioremediation efficiency on textile effluents containing a mixture of azo dyes. There was about 67% of reduction in color along with 34% of COD reduction by non-adapted fungal consortium while effective bioremediation efficiency was observed in adapted fungal consortium (Color 75% and COD 50%). The regression co-efficient for Langmuir and Freundlich adsorption isotherms were found to be higher for adapted fungal consortium (R2 = 0.97 and R2 = 0.92) than the non-adapted consortium (R2 = 0.97 and R2 = 0.85) proving that both monolayer and multilayer adsorption of dyes were observed on treating the samples with the adapted fungal consortium. On analyzing the results observed through chi-square test, the calculated value (28.712) was higher than the tabulated value (9.49) at a 4 degree freedom hence the hypothesis was rejected. So, there was an association between adapted fungal consortium and non-adapted fungal consortium and hence the adapted fungal consortium could be considered potentially useful for the bioremediation of textile effluent.  相似文献