Kumar P.N.,Rice Research |
Kumar P.N.,University of California at Davis |
Sujatha K.,Rice Research |
Laha G.S.,Rice Research |
And 14 more authors.
Phytopathology | Year: 2012
Broadening of the genetic base for identification and transfer of genes for resistance to insect pests and diseases from wild relatives of rice is an important strategy in resistance breeding programs across the world. An accession of Oryza nivara, International Rice Germplasm Collection (IRGC) accession number 105710, was identified to exhibit high level and broad-spectrum resistance to Xanthomonas oryzae pv. oryzae. In order to study the genetics of resistance and to tag and map the resistance gene or genes present in IRGC 105710, it was crossed with the bacterial blight (BB)-susceptible varieties 'TN1' and 'Samba Mahsuri' (SM) and then backcrossed to generate backcross mapping populations. Analysis of these populations and their progeny testing revealed that a single dominant gene controls resistance in IRGC 105710. The BC1F2 population derived from the cross IRGC 105710/TN1//TN1 was screened with a set of 72 polymorphic simple-sequence repeat (SSR) markers distributed across the rice genome and the resistance gene was coarse mapped on chromosome 7 between the SSR markers RM5711 and RM6728 at a genetic distance of 17.0 and 19.3 centimorgans (cM), respectively. After analysis involving 49 SSR markers located between the genomic interval spanned by RM5711 and RM6728, and BC2F2 population consisting of 2,011 individuals derived from the cross IRGC 105710/TN1//TN1, the gene was fine mapped between two SSR markers (RMWR7.1 and RMWR7.6) located at a genetic distance of 0.9 and 1.2 cM, respectively, from the gene and flanking it. The linkage distances were validated in a BC1F2 mapping population derived from the cross IRGC 105710/SM//2 × SM. The BB resistance gene present in the O. nivara accession was identified to be novel based on its unique map location on chromosome 7 and wider spectrum of BB resistance; this gene has been named Xa33. The genomic region between the two closely flanking SSR markers was in silico analyzed for putatively expressed candidate genes. In total, eight genes were identified in the region and a putative gene encoding serinethreonine kinase appears to be a candidate for the Xa33 gene. © 2012 The American Phytopathological Society.
Lakshmi R.R.,Dr Ysr Horticultural University |
Naidu L.N.,Dr Ysr Horticultural University |
Prasad A.H.,Rice Research |
Rao C.M.,Regional Agricultural Research Station |
Purushotham K.,Dr Ysr Horticultural University
Plant Archives | Year: 2012
A study was conducted to characterize the eighty four brinjal germplasm lines collected from different parts of the country using IBPGR descriptors at Horticultural Research Station, Venkataramannagudem, India. The data was collected on different plant, leaf, flower and fruit characters. Variability was observed for all the twenty five characters studied in the eighty four genotypes. The descriptors are helpful in breeding for high yielding, multiple disease resistant cultivars and improving the fruit quality characteristics.
Swamy B.P.M.,Rice Research |
Swamy B.P.M.,International Rice Research Institute |
Kaladhar K.,Rice Research |
Rani N.S.,Rice Research |
And 4 more authors.
Journal of Heredity | Year: 2012
The appearance and cooking quality of rice determine its acceptability and price to a large extent. Quantitative trait loci (QTLs) for 12 grain quality traits were mapped in 2 mapping populations derived from Oryza sativa cv Swarna × O. nivara. The BC2F2 population of the cross Swarna × O. nivara IRGC81848 (population 1) was evaluated during 2005 and that from Swarna × O. nivara IRGC81832 (population 2) was evaluated during 2006. Linkage maps were constructed using 100 simple sequence repeat (SSR) markers in population 1 and 75 SSR markers in population 2. In all, 21 QTLs were identified in population 1 (43% from O. nivara) and 37 in population 2 (38% QTLs from O. nivara). The location of O. nivara-derived QTLs mp1.2 for milling percent, kw6.1 for kernel width, and klac12.1 for kernel length after cooking coincided in the 2 populations and appear to be useful for Marker Assisted Selection (MAS). Four QTLs for milling percent, 1 QTL each for amylose content, water uptake, elongation ratio, 2 QTLs for kernel width, and 3 QTLs for gel consistency, each explained more than 20% phenotypic variance. Three QTL clusters for grain quality traits were close to the genes/QTLs for shattering and seed dormancy. QTLs for 4 quality traits were associated with 5 of the 7 major yield QTLs reported in the same 2 mapping populations. Useful introgression lines have been developed for several agronomic traits. It emerges that 40% O. nivara alleles were trait enhancing in both populations, and QTLs for grain quality overlapped with yield meta-QTLs and QTLs for dormancy and seed shattering. © 2012 The American Genetic Association.
Mangrauthia S.K.,Rice Research |
Malathi P.,Rice Research |
Agarwal S.,Rice Research |
Sailaja B.,Rice Research |
And 4 more authors.
Virus Genes | Year: 2012
Rice tungro disease is caused by a combination of two viruses: Rice tungro spherical virus and Rice tungro bacilliform virus (RTBV). This study was performed with the objective to decipher the molecular variability and evolution of RTBV isolates present in the tungro-affected states of Indian subcontinent. Phylogenetic analysis based on ORF-I, ORF-II, and ORF-IV sequences showed distinct divergence of Indian RTBV isolates into two groups; one consisted isolates from Hyderabad (Andhra Pradesh), Cuttack (Orissa), and Puducherry and another from West Bengal, Chinsura West Bengal, and Kanyakumari (Tamil Nadu). The results obtained from phylogenetic analysis were further supported with the single nucleotide polymorphisms (SNPs), insertion and deletion (INDELs) and evolutionary distance analysis. In addition, sequence difference count matrix revealed a maximum of 56 (ORF-I), 13 (ORF-II) and 73 (ORF-IV) nucleotides differences among all the Indian RTBV isolates taken in this study. However, at the protein level these differences were not significant as revealed by Ka/Ks ratio calculation. Sequence identity at nucleotide and amino acid level was 92-100 % (ORF-I), 96-100 % (ORFII), 94-100 %(ORF-IV) and 86-100 %(ORF-I), 98-100 % (ORF-II) and 95-100 % (ORF-IV), respectively, among Indian isolates of RTBV. The divergence of RTBV isolates into two independent clusters of Indian and non-Indian was shown with the help of the data obtained from phylogeny, SNPs, and INDELs, evolutionary distance analysis, and conserved motifs analysis. The important role of ORF-I and ORF-IV in RTBV diversification and adaptation to different rice growing regions is also discussed. © Springer Science+Business Media, LLC 2012.
Atray I.,Plant Molecular Biology Group |
Bentur J.S.,Rice Research |
Bentur J.S.,Agri Biotech Foundation |
Nair S.,Plant Molecular Biology Group
PLoS ONE | Year: 2015
The complete mitochondrial genome of the Asian rice gall midge, Orseolia oryzae (Diptera; Cecidomyiidae) was sequenced, annotated and analysed in the present study. The circular genome is 15,286 bp with 13 protein-coding genes, 22 tRNAs and 2 ribosomal RNA genes, and a 578 bp non-coding control region. All protein coding genes used conventional start codons and terminated with a complete stop codon. The genome presented many unusual features: (1) rearrangement in the order of tRNAs as well as protein coding genes; (2) truncation and unusual secondary structures of tRNAs; (3) presence of two different repeat elements in separate non-coding regions; (4) presence of one pseudo-tRNA gene; (5) inversion of the rRNA genes; (6) higher percentage of non-coding regions when compared with other insect mitogenomes. Rearrangements of the tRNAs and protein coding genes are explained on the basis of tandem duplication and random loss model and why intramitochondrial recombination is a better model for explaining rearrangements in the O. oryzae mitochondrial genome is discussed. Furthermore, we evaluated the number of iterations of the tandem repeat elements found in the mitogenome. This led to the identification of genetic markers capable of differentiating rice gall midge biotypes and the two Orseolia species investigated. © 2015 Atray et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Gangaiah B.,Indian Agricultural Research Institute |
Gangaiah B.,Rice Research |
Ahlawat I.P.S.,Indian Agricultural Research Institute
Indian Journal of Agronomy | Year: 2014
A field experiment was conducted during the rainy (kharif) and winter (rabi) seasons of 2006-07 and 2007-08 at New Delhi, to assess the performance of 3 cotton (Gossypium hirsutum L.)-wheat [Triticum aestivum (L.) emend. Fiori & Paol.] systems as affected by nitrogen (N) fertilization. In cotton, treatments formed by combination of 3 cotton hybrids [2 Bt (‘MRC 6304’ and ‘RCH 317’) and 1 non-Bt hybrid (‘LHH 144’)] in main plot and 4 levels of N fertilization (0, 60, 120 and 180 kg/ha) in sub-plots were tested. In succeeding wheat, cotton treatments were further sub-divided to accommodate 3 levels of N fertilization (0, 60, and 120 kg N/ha). Pooled data revealed that 2 Bt cotton hybrids being at par gave 55.4% (2.99 tonnes/ha) higher seed-cotton yield (SCY) than non Bt cotton hybrid (1.93 tonnes/ha) and the cotton hybrids did not markedly alter the performance of succeeding wheat. However, the system productivity (cotton-equivalent yield, CEY) of Bt cotton-wheat was 24.2% (4.72 tonnes/ha) higher than the non-Bt cotton-wheat system (3.80 tonnes/ha). The per cent contribution of Bt cotton to CEY of system (69.7) far exceeded that of non-Bt cotton (49.6). Both agronomic nitrogen-use efficiency (ANUE) and physiological nitrogen-use efficiency (PNUE) of Bt cotton and ANUE of succeeding wheat were higher than the non-Bt cotton and following wheat. Yield, N uptake of cotton, wheat and system increased with each successive increase of 60 kg N dose from 0 to 180 kg/ha. The N response of cotton was found to be quadratic with optimum dose of 173.0 kg/ha. ANUE and PNUE of cotton were the highest with 60 (5.73) and 120 kg N fertilization (17.05) and decreased thereafter with increasing N dose. Wheat crop responded to direct application of N up to 120 kg/ha. The currently recommended N input (300 kg/ha) of the non-Bt cotton (180 kg/ha)-wheat (120 kg/ha) system can be reduced by 27.8 kg with adoption of ‘MRC 6304’ Bt cotton. © 2014, Indian Society of Agronomy. All rights reserved.
Duraimurugan P.,Oilseeds Research |
Sampathkumar M.,Rice Research |
Srinivas P.S.,Oilseeds Research
Journal of Food, Agriculture and Environment | Year: 2015
Female calling behaviour and electrophysiological response of male to pheromone gland extracts of castor semilooper, Achaea janata L. (Lepidoptera: Noctuidae) were studied under laboratory conditions. Adult emergence occurred only at scotophase period with maximum of 58% male and 53% female moths during 6th and 7th hour of scotophase. Females exhibited a characteristic calling posture by extruding the pheromone gland from the tip of the abdomen. Both female age and time in the scotophase significantly influenced calling. Calling initiated during second scotophase and maximum calling occurred during fourth scotophase (66.7%). Most of the female calling (41.8%) occurred during 9th hour of the scotophase. Extracts of female pheromone gland assayed in electroantennogram elicited hyper sensitive reaction in male moths with a response of -2.745 mV. The present study gives detailed information on the behavioural biology of A. janata and optimal time for the pheromone extraction, which could facilitate exploiting pheromone technology for the monitoring and mass trapping of this pest in castor. © 2015, World Food Ltd. and WFL Publishers. All rights reserved.
Mishra J.S.,Weed Science Research |
Mishra J.S.,Sorghum Research |
Singh V.P.,Weed Science Research |
Bhanu C.,Weed Science Research |
And 3 more authors.
Indian Journal of Agricultural Sciences | Year: 2012
A field study was conducted to study the effect of methods of rice establishment, tillage and weed management techniques in rice-chickpea cropping system. Treatments included four crop establishment techniques (transplanting, puddling and broadcasting sprouted rice seeds, i.e wet-seeding and dry seeding under conventional and zero tillage systems) in rice and two tillage (zero and conventional) and two weed control methods (weedy check and pendimethalin 1.0 kg/ha as pre-emergence + one hand weeding at 30 days after sowing) in succeeding chickpea. Rice field was infested with jungle rice [Echinochloa colona (L.) Link], Caesulia (Caesulia axillaris Roxb.), sessile joyweed [Alternanthera sessilis (L.) DC.], and rice flat sedge (Cyperus iria L.) and chickpea with wild oats (Avena ludoviciana Dur.) and toothed burclover (Medicago hispida Gaertn.). Results revealed that methods of rice establishment did influence the weed dynamics in rice- chickpea system. Mean yield of zero-till direct-seeded rice (3 262 kg/ha) was as good as that of puddle broadcast rice (3 343 kg/ha) and better than the transplanted rice (3 038 kg/ha). Effective weed control in preceding chickpea benefitted the succeeding rice crop. Methods of rice establishment and tillage did not influence the chickpea yield. Infestation of weeds caused 78.45% reduction in yield of chickpea. Maximum seed yield of chickpea (2 813 kg/ha) was noticed in pendimethalin followed by one HW under conventional tillage. Zero till direct-seeded rice followed by zero-till chickpea system was the best combination for maximizing system productivity, profitability and energy efficiency.
Sunil N.,Regional Station |
Kumar V.,Regional Station |
Kumar V.,Rice Research |
Sivaraj N.,Regional Station |
And 4 more authors.
Indian Journal of Agricultural Sciences | Year: 2012
A total of 123 germplasm accessions of Pongamia pinnata were collected from peninsular India. Majority, i e 64 accessions (52%) were collected from an altitudinal gradient of 0 to 250 m with oil content ranging from 15.0 to 46.0% and only 0.8% of accessions collected from altitude more than 1 000 m have exhibited modest oil percent of 27.7%. Using DIVA-GIS software, grid maps indicating diversity for oil content and 100- seed weight were generated for these accessions. Highly variant lines for oil content were observed in Prakasam and Srikakulam districts of Andhra Pradesh. However, high diversity index for 100-seed weight was observed in Srikakulam and Chittoor districts of Andhra Pradesh. Rayagad district of Odisha was a potential region for diverse lines of Pongamia germplasm for various seed traits including oil content. High regions of diversity within the surveyed districts have been identified. The present study enabled us to find out suitable altitudinal gradient and diversity rich pockets from Peninsular India.