Browsing by Author "Roy, Subhas Ch."

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Open Access
Assessment of genetic diversity in F2 rice seed population of a cross between Tulaipanji and Ranjit using morphological, physicochemical and SSR markers
(University of North Bengal, 2013-03) Roy, Subhas Ch.
Tulaipanji rice (Oryza sativa L.) variety is a region specific traditional cultivar of North Dinajpur district (West Bengal). It is low yielding (1.8th) cultivar due to their poor harvest index and other genetic factors such as tendency to lodging and susceptibility to foliar diseases such as blast and bacterial blight, tungro virus etc. Tulaipanji Basmati aromatic and people prefer it due to its soft fluffy grain quality with mild fragrance and easy to digest. Hence it has high demand in the market and costs Rs. 80/kg. Demand gap can be fulfilled by developing a new improved variety of Tulipanji combining its grain quality attributes with high yield potential genes/QTLs and resistance to diseases. Hybridization was made (during kharif season 2011) between Tulaipanji and Ranjit (HYV) for the introgression of short stature, high yielding responsible genes/QTLs from Ranjit to Tulaipanji for its improvement. F2 seeds population were collected and analysed based on morphological and physicochemical parameters for their genetic variability and screening. Genetic diversity among the Fl plants and parental lines were analysed using microsatellite based SSR primer in PCR amplification. SSR markers in relation to disease resistance gene/QTL such as Xa21, Pita440 and Pib sub 3-5 were used to screen the breeding lines. Xa21specific amplified band was observed in cultivar Ranjit (HYV) which was located on chromosome 6 (resistance gene/QTL for bacterial blight) and accordingly introgressed into one of the line of F1 plants (Tulaipanji x Ranjit). There was no gene/QTL specific band was amplified for SSR marker of Pi440 and Pib sub 3-5 in the parental or Fl lines for blast resistance. Grain quality QTL specific markers such as Waxy, Sbe 2 and RM225 were employed to screen the F1 and parental lines for apparent amylose content (ACC). Apparent amylose content (ACC) was 22% in Tulaipanji and 25% in Ranjit and F2 seed showed in between 22 and 25% amylose. Breeding lines showing desired traits in relation to disease resistance and quality traits can be used for the development of improved Tulaipanji rice of North Dinajpur through marker assisted selection (MAS) using SSR markers
Open Access
Evaluation of genetic variation among fourteen rice (Oryza sativa L.) varieties (Landraces) of North Bengal using morphological traits
(University of North Bengal, 2010-03) Roy, Subhas Ch.; Rakshit, Dipayan; Sengupta, Sandeepan
The Northem region (North Bengal) of West Bengal possesses a rich genctic diversity of rice (Oryza sativa L).This region is known for growing one important rice variety Tulaipanji with GI number in the district of North Dinajpur and many other varieties of local landraces with tolerance to biotic and abiotic stresses. A considerable range of diversity and variation exists among the genetic resources of rice landraces of North Bengal. Prominent fourteen (14) landraces such as Sadanunia, Kalonunia, Dhepi, Banni, Dudkalam, Malsira, Lalpanati, Bhadoi, Ashami, and Gobindabhog, Enda, Chenga, Katharibhog, Tulaipanji are known for their special quality attributes were collected from the different districts of North Bengal. Genetic variation among these landraces was characterized by means of morphological traits such as seed sizes, shape, volume, colour, awn character, surface texture with husk (Microscopic observation) and pericurp colour. The Karl Pearson's simple matching coefficient was used to calculate the genetic diversity among the varieties. Similarity coefficient was ranged from 0.94 to 0.64 with an average of 0.79 among the 14 varieties. Clusier analysis based on genetic similarity of these varieties gave rise to three distinct groups The results suggested that the level of genetic diversity within this group of rice varieties of North Bengal was suficient for brecding programs and can be used to establish genetic relationships among them on the basis of morphological traits.
Open Access
Morphological characterization of wild rice (Oryza rufipogon Griff.) of NBU campus (West Bengal) for in situ conservation and germplasm enhancement
(University of North Bengal, 2014-03) Roy, Subhas Ch.
Asian wild rice Oryza rufipogon Griff. (Poaceae) is considered as a progenitor of the cultivated rice (Oryza sativa L). lt is a source of many biotic and abiotic stress tolerance genes and these are utilized for genetic improvement of cultivated rice. Thus it needs immediate attention with high priority so that we could not loss this agriculturally important Oryza gene pool. Natural population of Oryza rufipogon in the North Bengal University campus is characterized based on phylogeographic and morphological parameters for conservation purposes. Twenty-five plants were considered randomly to measures twenty-six different types of morphological passport data for genetic relatedness analysis within the population. Diagnostic characters are provided to delineate the species morphologically. Plant is annual ecotype having short to intermediate culms height (64 cm-145 cm), and 0.5- 1.6 cm in thickness. Profuse fibrous roots of 2 mm thick and 3-9 cm long creamy-white in colour grows from the floating nodes, node region is solid and pinkish in colour (5-7 mm long). Flag leaf length ranges from 13 cm-40 cm with 0.3 cm 1.8 cm width. Flag leaf blade attitude is varying from deflexed to horizontal to semierect. Auricle was hard, curved, glabrous and 13-15.5 mm in size. Two-cleft ligule length ranges 17 mm to 35 mm. Panicle length varies from 15.4 cm 30 cm with l cm-8 cm wide with 5-13 primary branches. Attitude ofprimary branches is spreading, well exserted (100%), alternately arranged on the wavy axis. Length of the lemma varies 6-11 mm and 1.4-2.3 mm wide, lemma-awn junction marked by a pinkish pubescent constriction with 23-80 mm long red awn. Yellow colour anthers vary in length 4-8 mm long. Stigma was bifurcated (>2 mm) and purple in colour comes out from the spike lets. Seeds (blackish) are harvested during November-December and vary in length (7.5 mm - 10 mm). Density of fertile spikelets ranges from 15 to 82. Grain length/breadth ratio was 3.73 (average) and average kernel length/breadth ratio was 3.99. The results suggest that the population of NBU campus are genetically diversified, heterogeneous and should be conserved in situ to protect this precious genetic resource as separate ecological race (ecotype or intergrade) for germplasm enhancement.