Int.J.Curr.Microbiol.App.Sci (2018) 7(9): 1744-1755 1744 Original Research Article https://doi.org/10.20546/ijcmas.2018.709.211 Phenotypic Screening and Evaluation of Sub1 Introgressed Lines in Popular Rice Varieties Ranjit and Bahadur of Assam, India Ashish Gautam 1* , S.K. Chetia 2 , M.K. Modi 3 and T. Ahmed 2 1 Department of Plant Breeding and Genetics, 3 Department of Agricultural Biotechnology, AAU, Jorhat-785013, Assam, India 2 Regional Agricultural Research Station, AAU, Titabar, Assam, India *Corresponding author ABSTRACT Introduction Rice (Oryza sativa L.) is the staple food of more than half of the world population. It is the dominant and only suitable crop in the rainfed and lowland areas of India. Submergence stress is a major constraint to rice production in areas of high rainfall and it adversely affects farmers living on 10-15 million hectares of rainfed lowland rice in South and Southeast Asia (Neeraja et al., 2007). To meet the demand of the ever increasing global population, greater production of rice is needed from this flood prone ecosystem. According to the estimate of World Bank (World Bank, 2008), flood International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 09 (2018) Journal homepage: http://www.ijcmas.com Phenotypic screening during kharif 2015 and evaluation of Sub1 introgressed lines in Ranjit and Bahadur for submergence tolerance was done with the 35 genotypes. Out of 35 genotypes 32 were Sub1 introgressed BC 2 F 3 lines (24 BC 2 F 3 lines of the cross -Ranjit x Swarna-Sub1and 8 BC 2 F 3 lines of the cross -Bahadur x Swarna-Sub1) with three parents i.e. Ranjit, Bahadur, and Swarna-Sub1. The phenotypic screening of genotypes showed that all Sub1 introgressed lines had significantly higher survival rates as compared with the original recipient parents whereas less change in plant height was observed. The Sub1 introgressed lines in BC 2 F 3 generation showed lesser elongation during submergence as compared to the parents and the susceptible check IR42. The analysis of variance revealed the existence of significant variation among the genotypes for grain yield and all other morpho-physiological quantitative traits. High estimates of genotypic and phenotypic variation in case of morphological characters like stem thickness, panicle number per plant indicated that selection would be effective for these characters. Amongst all the morpho- physiological quantitative traits, high heritability (>80) with high genetic advance (>20) as percent of mean estimates were recorded for leaf length of blade, stem thickness, leaf width of blade, grain weight of 1000 fully developed grains and grain width. The high estimates of heritability for these characters also indicated considerable genetic variation and lower influence of environment in the expression of these characters. High genetic advance coupled with high heritability estimates indicates that these traits are apparently controlled by additive genes. Thus these traits deserve top most priority in selection. Keywords Bahadur, Phenotyping, Ranjit, Rice, Sub1, Submergence tolerance Accepted: 12 August 2018 Available Online: 10 September 2018 Article Info