Browsing by Author "N. Rai"

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Detection of tomato leaf curl virus resistance and inheritance in tomato (Solanum lycopersicum L.)
(Cambridge University Press, 2015) R.K. Singh; N. Rai; M. Singh; S. Saha; S.N. Singh
Tomato leaf curl virus (TLCV) is a major viral disease in tomato that causes quantitative and qualitative losses to the crop. One hundred and fifty three tomato genotypes were screened for three consecutive years (2006-09) under glasshouse and field conditions for TLCV resistance. The incidence of disease was higher during the Rabi season as compared to the Kharif season trials. The reactions of different genotypes were studied by artificial inoculation. Based on the coefficient of infection, nine genotypes (viz. EC-520049 (Solanum chmielewskii), EC-520058, EC-520060 and EC-520061 (S. habrochaites), EC-520070, EC-520071, EC-520077, EC-520079 (S. pimpinellifolium) and H-88-78-1(S. lycopersicum; a derivative of S. habrochaites f. glabratum) were found to be highly resistant in both environments. H-88-78-1 was used for inheritance studies during 2008-10. Using F2 Mendelian segregation, populations showed a 3 (resistant):1 (susceptible) ratio for TLCV disease and were proposed to have both additive and dominant non-allelic gene interactions for various traits. Copyright © 2014 Cambridge University Press.
Emphysematous pyelonephritis: A report of three cases
(2007) R. Aggarwal; S. Kumar; R. Goyal; V. Prakash; N. Rai; N.K. Agrawal; S.K. Singh
Emphysematous pyelonephritis (EPN) is a rare necrotizing infection of renal parenchyma and/or urinary tract caused by gas producing organisms more commonly associated with diabetes mellitus. It has life threatening potential primarily due to septicemia and multiorgan failure and often requires nephrectomy. We report three patients with EPN who were managed with medical treatment and nephrostomy. © 2007 Diabetes India.
Genetic analysis to identify good combiners for ToLCV resistance and yield components in tomato using interspecific hybridization
(Springer, 2014) Ramesh K. Singh; N. Rai; Major Singh; S.N. Singh; K. Srivastava
The interspecific hybridization for tomato leaf curl virus (ToLCV) resistance was carried out among 10 genetically diverse tomato genotypes (diversified by 50 SSR markers). Among the 10 parents, four susceptible cultivars of Solanum lycopersicum were crossed with six resistant wilds, such as S. pimpinellifolium, S. habrochaites, S. chemielewskii, S. ceraseforme, S. peruvianum and S. chilense in a line × tester mating design. All the 24 hybrids and their parents were grown in the field and glasshouse conditions to determine the general-combining abilities (GCA) and specific-combining abilities (SCA). The variances due to SCA and GCA showed both additive and nonadditive gene effects. Based on GCA estimates, EC-520061 and WIR-5032 were good general combiners while based on SCA estimates, PBC × EC-520061 and PBC × EC-521080 were best specific combiners for coefficient of infection and fruit yield per plant in both the environments. These lines could be selected and utilized in ToLCV resistance and high yield breeding programme for improving the traits. © 2014, Indian Academy of Sciences.
Genetic relationship among Hyacinth bean (Lablab purpureus) genotypes cultivars from different races based on quantitative traits and random amplified polymorphic DNA marker
(2010) N. Rai; Ashish Kumar; P.K. Singh; M. Singh; D. Datta; M. Rai
Genetic improvement of the thirty Hyacinth bean cultivars from different races were evaluated using RAPD markers which is essential to enhance the crop for economically and agriculturally important traits. RAPD markers were efficient in separating cultivars according to different races. Twenty six decamer primers could generate a total number of 148 bands out which 70.27% (104) were polymorphic. The number of amplification products produced by each primer varied from 4 to 9 with an average of 5.69 bands per primer. The size of amplified fragments ranged from 250 to 3000 bp. RAPD based dendrogram showed similarity ranged from 0.38 to 0.96. Genetic distances were concluded using Sorenson Dices similarity coefficient. The genetic relationship obtained with these markers was dissimilar to that provided by morpho-agronomical trait. Genetically distinct cultivars were identified that could be potentially important source of germplasm for further crop improvement programme in the country. © 2010 Academic Journals.
Genetics of resistance to early blight disease in crosses of wild derivatives of tomato
(Elsevier B.V., 2017) A.K. Singh; N. Rai; R.K. Singh; S. Saha; R.K. Rai; R.P. Singh
The objective of this study was to determine the heterosis, inbreeding depression and genetics for yield, quality and resistance to early blight in tomato. Consequently, twenty inter-specific crosses of tomato were developed by crossing five susceptible cultivars and four wild resistant accessions and tested in field and glasshouse conditions for early blight (EB) resistance. Biochemical responses were also critically studied both in parents and hybrids. All the crosses showed moderately susceptible reaction except five crosses of EC-520061 (Solanum habrochaites). Biochemically the wild parents exhibited better results over susceptible parents but their hybrids showed moderate reaction for early blight resistance. High level of phenol was found both in resistant parents and hybrids. Among the 20 crosses, those made by EC-520061 and H-88-78-1 manifested resistance capacity, low heterosis and high inbreeding depression for EB disease. For yield associated traits most of the crosses expressed high heterosis and low inbreeding depression which indicated better yield capacity. The crosses made by EC-520061 (S. habrochaites) segregated in 3:1 (resistant:susceptible) Mendelian ratio and indicated monogenic dominant and additive gene effects. Remaining crosses showed 1:2:1 (resistant:intermediate:susceptible) genetic ratio and indicated heterozygous nature of crosses mediated by multiple genes or QTLs. This fact can be utilized in future tomato breeding program for developing resistant varieties against EB disease. © 2017
Genotypes x environment interaction studies on early blight disease of tomato
(Society for Advancement of Horticulture, 2013) A.K. Singh; N. Rai; R.K. Singh; R.P. Singh; Vineeta Singh
Experiments were conducted for three years to study the interaction between tomato genotypes and environment against early blight disease caused by Alternaria solani. Fifty one genetically diverse genotypes of tomato were screened in field conditions against early blight in Rabi season of 2006-09 at Indian Institute of Vegetable Research, Varanasi, India. Results revealed that genotype LA-3980 was resistant while, EC-520058, EC-520060, EC-520061, EC-520070, EC-521080, WIR-3928 and H-88-78-1 were highly resistant. All the resistant and highly resistant lines belong to wild species except H-88-78-1 and LA-3980. Only three genotypes, EC-520061, EC-520070 and H-88-78-1 were stable in each environment for resistance to early blight disease in tomato. Relationship of environment with resistant genotypes indicated that EC-520061, EC-520070, WIR-3928 and H-88-78-1 had low regression coeffi cient (b<1) and low deviation from regression (sd2=<1) than others (b= >1and sd2=>1) indicating stable and adaptive genotypic resistance to early blight. Hence these genotypes may be used as donor parent for development of early blight resistant/ tolerant varieties / lines.
Identification of host plant resistant to Dolichos Yellow Mosaic Virus (DYMV) in Dolichos bean (Lablab purpureus)
(2012) P.K. Singh; Ashish Kumar; N. Rai; D.V. Singh
Three hundred Dolichos bean (Lablab purpureus) genotypes were screened against Dolichos Yellow Mosaic Virus (DYMV) disease. Initial screening was done under field conditions where disease incidence was calculated for each genotype. Subsequently, selfed progenies of 34 symptomless lines were challenged by sap inoculation under field conditions, out of which only three genotypes, viz. VRSEM-894, VRSEM-887 and VRSEM-860 did not show any symptoms. Using root stalk of susceptible genotype (Ankur Goldy), these three putative symptomless genotypes were further challenged by grafting. The resistant reactions of VRSEM-894, VRSEM-887 and VRSEM-860 were confirmed as even after 60 days of successful grafting, no viral symptom appeared on all the grafted plants of these genotypes. When subjected to PCR amplification with DYMV coat protein gene specific primer, these three symptomless genotypes did not show any amplification, suggesting that there was no infection of Dolichos Yellow Mosaic Virus in those genotypes.
Inheritance study in tomato (Solanum lycopersicum) for Tomato leaf curl virus (ToLCV) resistance
(Indian Council of Agricultural Research, 2015) R.K. Singh; N. Rai; P. Kumar; A.K. Singh
A breeding programme was developed from an initial S. lycopersicum × S. lycopersicum (H 88-78-1) cross. The objective of this study was to determine the inheritance of resistant to leaf curl virus and yielding capacity in four crosses made within and between gene pools (TLBR 3 × H 88-78-1, PKM 1 × H 88-78-1, FLA 7421 × H 88-78-1 and Vaibhaw × H 88-78-1) using generation means analysis with five generations (P1, P2, F1, F2and F3) of each population under two environment (field and glasshouse). Results showed that the character of plants and fruits morphology was fit on 1:2:1 (P1: intermediate: P2) and ToLCV (PDI) value was fit on 3:1 (resistant: susceptible) Mendalian ratio in each four F2 populations. In the present study, it was concluded that the generation mean analysis showed monogenic and partial recessiveness and incomplete penetrance. Each population displayed the additive and dominant gene action according to their heritability for using characters. The partial resistance derived from H 88-78-1 will be useful in homozygosis or may be combined with other resistance genes from other sources and can be grown in any climate challenging area.
Selection of tomato genotypes resistant to tomato leaf curl virus disease using biochemical and physiological markers
(Cambridge University Press, 2015) R.K. Singh; N. Rai; M. Singh; S.N. Singh; K. Srivastava
A total of 34 tomato genotypes (24 F1+10 parents) were tested for resistance to tomato leaf curl virus (ToLCV) disease by various whitefly inoculation techniques under field and insect-proof glasshouse (mass and cage) conditions. Of the ten tomato parental lines, two accessions [EC-520061 (Solanum habrochaites) and EC-521080 (Solanum pimpinellifolium)] were identified as highly resistant while four accessions (EC-520049, EC-528372, WIR-5032 and WIR-3957) of wild species were resistant to ToLCV. Out of the 24 F1 crosses, PBC×EC-520061, H-86×EC-520061, H-24×EC-520061 and DVRT-2×EC-520061 were found to be highly resistant against ToLCV disease. Biochemical (total phenol and total sugar concentration) and physiological (chlorophyll content and leaf area index) parameters were also used in healthy and disease-inoculated leaves of ten parents and six F1 hybrids to test the conformity of ToLCV-resistant and susceptible disease reactions. The results showed that among the 16 genotypes (10 parents+6 F1), EC-520061, EC-520049, PBC×EC-520061 and H-86×EC-520061 were stable for both biochemical and physiological markers while EC-521080 showed higher accumulations of total phenol and sugar concentrations and reduced leaf size between healthy and disease-inoculated leaves. The present study demonstrates the importance of the whitefly inoculation technique and biochemical and physiological markers in virus resistance screening programmes, and identifies a potential source of resistance to the ToLCV in Solanum species. © 2014 Cambridge University Press.
Snowmelt runoff and groundwater discharge in Himalayan rivers: a case study of the Satluj River, NW India
(Springer Verlag, 2018) A.S. Maurya; S.P. Rai; N. Joshi; K.S. Dutt; N. Rai
The Himalayas are one of the largest cryospheric systems outside the Polar Regions, and include more than 12,000 glaciers spread over an area of about 33,000 km2. The Himalayan glaciers and snow packs retreating at an accelerating rate, thereby creating an alarming situation for the huge population that resides in northwestern India and southeastern Pakistan, as they depend on surface water resources in the region and rivers emanating from the Himalayas. This work attempts to quantify the contribution of different sources such as glacial/ice/snow melt and groundwater discharge to the Satluj River using the stable isotopes based hydrograph separation method at Ropar (foot hill) and Yusufpur in plain of Punjab, India. A mass balance model of three-component mixing has been engaged using the values of δ18O and electrical conductivity of the river water, and its discharge fraction, to estimate the time-varying relative proportion of each component from July 2013 to January 2014. The proportion of glacier melt was found to peak up to ~ 64% at Ropar and ~ 15% at Yusufpur during the wet summer months. The fraction of groundwater discharge was found to vary between 10–20% at Ropar and 25–35% at Yusufpur (Punjab plain) over time. The observed trend of d-excess (deuterium excess) values of river water also suggests that the glaciers and snow packs at higher altitudes contain a significant fraction of snow derived from vapor originating in the Mediterranean region, driven by the mid-latitude westerlies known as western disturbances. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.