Browsing by Author "Timir Baran Jha"

Now showing 1 - 4 of 4

Characterization of some Indian Himalayan Capsicums through floral morphology and EMA-based chromosome analysis
(Springer-Verlag Wien, 2017) Timir Baran Jha; Partha Sarathi Saha
The North Eastern Himalayan (NEH) regions of India are considered as one of the major repositories of the “Capsicum annuum complex” which comprises of three cultivated species namely C. annuum, C. frutescens, and C. chinense. The interspecific delimitation within this large complex is ill-defined due to poorly developed crossing barriers and lack of discontinuous morphological characters. The present study elucidates the relationship among nine different cultivars of three Capsicum species on the basis of floral morphology and karyological parameters for the first time. Different floral characteristics such as margins and constrictions of calyx, type of pedicel, flower size, and color were found to have paramount importance in the species delimitation within the studied members of “C. annuum complex.” The present karyomorphometric study explicitly revealed differences between the observed chromosomal data such as karyotype formulae, ordering of satellite bearing chromosome pairs and total diploid chromatin length which aid in resolving interspecific relationship among the studied cultivars of Capsicum. The present analyses unambiguously distinguished all cultivars of C. annuum from the members of C. frutescens and C. chinense and also proposed that among the five cultivars of C. annuum, Ghee lanka was comparatively distant from the other four cultivars on the basis of their karyomorphological characteristics. For the first time karyotype of hottest Indian chili is included in this paper. Comprehensive knowledge on floral morphology and karyotypes of some Himalayan Capsicums not only help to conserve genetic diversity but also help capsicum breeders for their basic and applied research. © 2016, Springer-Verlag Wien.
Chromosome morphometric analysis of Indian cultivars of Lens culinaris Medik. using EMA based Giemsa staining method
(Taylor and Francis Ltd., 2017) Timir Baran Jha; Partha Sarathi Saha; Mousumi Adak; Sumita Jha; Partha Roy
The influence of biotic, abiotic and climatic changes on crop production is becoming increasingly evident. Gaps in demand and supply of lentils, one of the few protein-rich crops in India, are gradually increasing. Of seven estimated species of lentil, six are wild and the other, Lens culinaris, is the only species under cultivation, with a large number of cultivars. Chromosome analysis is beneficial to breeders and genome researchers in crop improvement programmes. However, a chromosomal database of this important crop is not available in India. The present paper has described a detailed chromosome analysis of 21 certified Indian cultivars of L. culinaris using enzymatic maceration and air drying (EMA) based Giemsa staining methods for the first time. Uniform chromosomal preparations have resulted in variation in average chromosome size (4.94–9.8 μm), total chromatin length (69.18–137.24 μm), and satellite bearing chromosome number (third, fourth and fifth) among the cultivars. Though our results revealed similar karyotypic formulae and symmetrical karyotype, a scatter diagram of intra-chromosomal asymmetry index (A1) versus inter-chromosomal asymmetry index (A2) groups them into five distinct clusters. Such information may be helpful for conservation of genetic diversity and for future lentil breeding programmes. © 2017 Dipartimento di Biologia Evoluzionistica, Università di Firenze.
Morphological and cytogenetical characterization of ‘Dalle Khursani’: a polyploid cultivated Capsicum of India
(Elsevier B.V., 2017) Timir Baran Jha; Partha Sarathi Saha; Sayantani Nath; Anusree Das; Sumita Jha
A morphologically different, perennial and highly pungent Capsicum cultivar ‘Dalle Khursani’ is available in the Darjeeling district of West Bengal over many decades. Its counterpart in Sikkim was identified as polyploid Capsicum cultivar with 2n = 4x = 48 chromosomes. However, cytogenetical status of the cultivar growing in West Bengal was lacking. The present study has carried out extensive morphological, chromosomal and molecular analysis on seven ‘Dalle Khursani’ populations of West Bengal. Our results on flower morphology explicitly delimit ‘Dalle Khursani’ populations from the members of ‘C. annuum complex’. Somatic and gametic chromosome analysis has clearly established their polyploid chromosome number 4x = 48 and allopolyploid nature of the cultivar (2n = 4x = 48). Fluorescent banding analysis with CMA revealed CMA + ve/DAPI-ve heterochromatin blocks in four ‘Dalle Khursani’ populations for the first time indicating the prevalence of GC rich heterochromatin in the studied taxon. RAPD based genomic DNA analysis has exhibited similar banding profile within the populations and their complete difference from the diploid members of ‘C. annuum complex’. Our present studies in conformity with our earlier report have firmly established that allopolyploidy in Capsicum is not a rarity. It is available in Indian states and will help the Capsicum researchers and breeders in their future crop improvement programmes. © 2016 Elsevier B.V.
Searching chromosomal landmarks in Indian lentils through EMA-based Giemsa staining method
(Springer-Verlag Wien, 2016) Timir Baran Jha; Mihir Halder
Lentil is one of the oldest protein-rich food crop with only one cultivated and six wild species. India is one important cultivator, producer and consumer of lentils and possesses a large number of germplasms. All species of lentil show 2n = 14 chromosomes. The primary objective of the present paper is to search chromosomal landmarks through enzymatic maceration and air drying (EMA)-based Giemsa staining method in five Indian lentil species not reported elsewhere at a time. Additionally, gametic chromosome analysis, tendril formation and seed morphology have been studied to ascertain interspecific relationships in lentils. Chromosome analysis in Lens culinaris, Lens orientalis and Lens odemensis revealed that they contain intercalary sat chromosome and similar karyotypic formula, while Lens nigricans and Lens lamottei showed presence of terminal sat chromosomes not reported earlier. This distinct morphological feature in L. nigricans and L. lamottei may be considered as chromosomal landmark. Meiotic analysis showed n = 7 bivalents in L. culinaris, L. nigricans and L. lamottei. No tendril formation was observed in L. culinaris, L. orientalis and L. odemensis while L. nigricans and L. lamottei developed very prominent tendrils. Based on chromosomal analysis, tendril formation and seed morphology, the five lentil species can be separated into two distinct groups. The outcome of this research may enrich conventional and biotechnological breeding programmes in lentil and may facilitate an easy and alternative method for identification of interspecific hybrids. © 2015, Springer-Verlag Wien.