~ 176 ~ Journal of Pharmacognosy and Phytochemistry 2018; SP2: 176-181 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; SP2: 176-181 Hari Shankar Research Scholar, Bhagwant University, Department of Agriculture, Ajmer, Rajasthan, India Narendra Pratap Narendra Dev University of Agriculture & Technology, Kumarganj Faizabad, Uttar Pradesh, India Devaraja Achar HOD, Biotechnology, Indo- American Hybrid seeds (I) Pvt. Ltd.,Bangalore 221005, Uttar Pradesh, India Vikram Kumar Yadav Research Scholar, Bhagwant University, Department of Agriculture, Ajmer, Rajasthan, India Amit Kumar Research Scholar, Bhagwant University, Department of Agriculture, Ajmer, Rajasthan, India Correspondence Hari Shankar Research Scholar, Bhagwant University, Department of Agriculture, Ajmer, Rajasthan, India National Conference on Conservation Agriculture (ITM University, Gwalior on 22-23 February, 2018) Introgression of blast resistance gene in Kalanamak short grain rice variety through marker assisted backcross breeding Hari Shankar, Narendra Pratap, Devaraja Achar, Vikram Kumar Yadav and Amit Kumar Abstract Blast is the most common biotic stress leading to the reduction of rice yield in many rice-growing areas of the world, including India. Improvement of blast resistance of rice varieties cultivated in blast endemic areas is one of the most important objectives of rice breeding programs. Kalanamak is one of the finest quality scented rice of India (Singh et al., 2003) [21] . Kalanamak rice is affected by blast disease, lodging and submergence intolerance due to which its yield reduces. In this study, the marker-assisted backcrossing strategy was applied to improve the blast resistance of the Kalanamak rice variety by introgressing blast resistance genes from the Tetep (blast resistance) variety. One blast resistance genes, Pi-54 pyramided into Kalanamak. Foreground selection coupled with stringent phenotypic selection identified 12 plants homozygous for the Pi-54 gene, and background selection revealed more than 95% genome recovery of Kalanamak in advanced blast resistant lines. Phenotypic screening against blast disease indicated that advanced homozygous blast resistant lines were strongly resistant. The newly developed blast resistant improved lines will retain the high adoptability of Kalanamak by farmers. The present results will also play an important role in sustaining the short grain aromatic (Kalanamak) rice production for Eastern parts of India. Keywords: rice, blast resistance, gene pyramiding, MABC, marker-assisted backcrossing, biotic stress Introduction Aromatic rice, which has stronger aroma than ordinary rice, has more in demand in different countries of the world. India is one of the largest exporter of basmati rice in world (Husaini et al., 2009) [8] . The consumer demand has increased markedly to pay a premium price for fragrance (Louis et al., 2005) [12] . Aromatic rice varieties grow best and produce finest quality grains under cool, humid conditions, which are common in Himalayan Tarai of U.P, Uttarakhand and foot hills of Vindhya Hills. Among non-basmati aromatic rice, Kalanamak is the most popular scented rice variety grown in Uttar Pradesh. It is among one of the most important scented rice varieties of India. This variety is famous for its taste and aroma. It used for cooking at marriages is considered auspicious and its aroma is believed to be purifying the atmosphere. Its name derived from its black husk. Kalanamak is very susceptible to various diseases such as Blast and other mineral deficiency diseases. Among them rice blast is devastating plant diseases, for Kalanamak. Rice blast caused by the fungal pathogen Pyricularia grisea (Magnaporthe grisea). This fungus attacks all aerial parts of the rice plants at all stages of growth, although the leaves and the neck of the panicle are most commonly affected. Blast is the one of the main diseases of rice crops causing crop loss in both temperate and tropical rice growing regions (Mackill and Bonman, 1992) [13] . The main agent causing this disease is the fungus Magnaporthe oryzae. Thus, blast resistance in rice plants has been one of the most important traits being pursued in breeding programs over several decades. Different breeding strategies have been adopted to achieve this serious challenge, such as the use of field resistance to blast disease and the introduction of resistance genes into the rice susceptible cultivar objective (Kushibuchi, 1997) [11] . Approximately 347 QTLs linked to blast resistance (Koide et al., 2009; Ballini et al., 2013) [10, 2] and more than 100 blast resistant genes have been identified from diversified rice germplasm (Divya et al., 2014) [5] . The identified blast R genes