Browsing by Author "Sethy, Niroj K."

Now showing 1 - 4 of 4

Development of sequence-tagged microsatellite site markers for chickpea (Cicer arietinum L.)
(Wiley-Blackwell, 2006) Choudhary, Shalu; Sethy, Niroj K.; Shokeen, Bhumika; Bhatia, Sabhyata
Microsatellite loci were identified from chickpea (Cicer arietinum L.), the third most important grain legume crop in the world. A total of 13 sequence-tagged microsatellite markers were developed using two different approaches: (i) amplification using degenerate primers and (ii) cloning of intersimple sequence repeat (ISSR)-amplified fragments. Thirty-five chickpea accessions were analysed, which resulted in a total of 30 alleles at the 13 loci. The observed heterozygosity ranged from 0.1143 to 0.4571 with an average of 0.2284. The cross-species transferability of the sequence-tagged microsatellite site (STMS) markers was checked in Cicer reticulatum, the wild annual progenitor of chickpea. These microsatellite markers will be useful for assessing the genetic diversity patterns within chickpea as well as aid in construction of intra- and interspecific genetic linkage maps.
Development of STMS markers from the medicinal plant Madagascar periwinkle (Catharanthus roseus L.) G. Don
(Wiley-Blackwell, 2005) Shokeen, Bhumika; Sethy, Niroj K.; Choudhary, Shalu; Bhatia, Sabhyata
We report the isolation and characterization of the first set of sequence-tagged microsatellites sites (STMS) markers in Catharanthus roseus, a plant with a vast range of medicinal uses. The microsatellite loci were cloned from an enriched library constructed using degenerate primers. Based on the microsatellite motifs, seven STMS primer pairs were designed. They were used to amplify 32 accessions of C. roseus and one accession of Catharanthus trichophyllus. The primers amplified an average of 3.86 alleles per locus. The observed heterozygosity ranged from 0.2903 to 0.9688 with an average of 0.7511. The STMS markers of C. roseus also amplified corresponding loci in a related species (C. trichophyllus) suggesting conservation of the loci across the genus. These markers will prove useful for genetic diversity analysis and linkage map construction in C. roseus.
Isolation and characterization of sequence-tagged microsatellite sites markers in chickpea (Cicer arietinum L.)
(Wiley-Blackwell, 2003) Sethy, Niroj K.; Shokeen, Bhumika; Bhatia, Sabhyata
In this study we report the isolation of microsatellite sequences and their conversion to sequence-tagged microsatellite sites (STMS) markers in chickpea (Cicer arietinum L.). Thirteen putative recombinants isolated from a chickpea genomic library were sequenced, and used to design 10 STMS primer pairs. These were utilized to analyse the genetic polymorphism in 15 C. arietinum varieties and two wild varieties, C. echinospermum and C. reticulatum. All the primer pairs amplified polymorphic loci ranging from four to seven alleles per locus. The observed heterozygosity ranged from 0 to 0.6667. Most of the STMS markers also amplified corresponding loci in the wild relatives suggesting conservation of these markers in the genus. Hence, these polymorphic markers will be useful for the evaluation of genetic diversity and molecular mapping in chickpea.
Molecular genetics and breeding of grain legume crops for the semi-arid tropics
(Springer, 2007) Varshney, Rajeev K.; Hoisington, David A.; Upadhyaya, Hari D.; Gaur, Pooran M.; Nigam, Shyam N.; Saxena, Kulbhushan; Vadez, Vincent; Sethy, Niroj K.; Bhatia, Sabhyata; Aruna, Rupakula; Gowda, M. V. Channabyre; Singh, Nagendra K.
Grain legumes are important crops for providing key components in the diets of resource-poor people of the semi-arid tropic (SAT) regions of the world. Although there are several grain legume crops grown in SAT, the present chapter deals with three important legumes i.e. groundnut or peanut (Arachis hypogaea), chickpea (Cicer arietinum) and pigeonpea (Cajanus cajan). Production of these legume crops are challenged by serious abiotic stresses e.g. drought, salinity as well as several fungal, viral and nematode diseases. To tackle these constraints through molecular breeding, some efforts have been initiated to develop genomic resources e.g. molecular markers, molecular genetic maps, expressed sequence tags (ESTs), macro-/micro- arrays, bacterial artificial chromosomes (BACs), etc. These genomic resources together with recently developed genetic and genomics strategies e.g. functional molecular markers, linkage-disequilibrium (LD) based association mapping, functional and comparative genomics offer the possibility of accelerating molecular breeding for abiotic and biotic stress tolerances in the legume crops. However, low level of polymorphism present in the cultivated genepools of these legume crops, imprecise phenotyping of the germplasm and the higher costs of development and application of genomic tools are critical factors in utilizing genomics in breeding of these legume crops.