Indian Journal of Biotechnology Vol. 19, October 2020, pp 292-298 Marker assisted selection and F 6 generation characterization of Katarni rice (Oryza sativa L.) derived lines Kumari Suvidha, Kumari Neha, Sundaram Bharti, Satyendra, Tirthartha Chattopadhyay, Suresh Prasad Singh and Mankesh Kumar* Department of Plant Breeding and Genetics, Bihar Agricultural University, Sabour, Bhagalpur, Bihar-813210, India Received 10 August 2020; revised & accepted 26 September 2020 Characterisation of promising progenies in the advanced generations of breeding schemes is essential to know about their distinctness from the parents as well as other existing cultivars. This also requires for developing them as a variety or pre- breeding line. In this study, an attempt was made for establishing distinctness of twenty five F 6 families of Katarni x Rajendra Sweta, Katarni x IR64 and Katarni X MTU7029 along with 14 rice genotypes. The genotypes were characterised with the help of thirty simple sequence repeat (SSR) markers. The markers generated 107 polymorphic alleles with an average of 3.56 alleles per locus. The values polymorphic information content (PIC), expected heterozygosity (H) and discriminating power (D) of markers varied from 0.41 to 0.48, 0.32 to 0.50 and 0.75 to 0.96, respectively. At 0.38 similarity coefficient four distinct clusters were formed and cluster I had highest number accessions of F 6 families. The study advocated use of (SSR) markers as a complementary tool to morphological descriptors to decipher the distinctiveness of the promising lines in advanced generations of a breeding programme. Keywords: Katarni rice, badh2, sd1, SSR markers, similarity coefficient Introduction Aromatic rice is a small and special group of rice which is highly priced due to their specific pleasant aroma and other special qualities which comes after cooking 1 . Katarni is one of the famous landrace of rice of Bihar state which is renowned for its special aroma, unique medium fine grain and cooking qualities. Due to its special grain qualities and uniqueness, a tag for geographical indication (GI) has recently been granted to this rice in April, 2018 (Geographical Indication no. 553) (http:// ipindiaservices.gov.in/GIRPublic/Application/Details/ 553) by the Office of Intellectual Properties Rights, New Delhi, India. However, like other traditional rice landraces, it also suffers from a problem of lodging due to its tall height, weak culm and uncontrolled use of nitrogenous fertilizers. Its culm is so weak that the plants often lodge due to the weight of fully matured grains resulting in very low yielding ability (25-30 q/ha) 2 . Hence, isolation and exploitation of dwarfness in Katarni will help not only in increasing production area but also safeguard the interest of the farmers. Dwarf cultivars are more resistant to damage by lodging and it has more grain yield in response to fertilizer application. The semi-dwarf mutants (sd1) in rice are mainly deficient in gibberellic acid (GA) due to a deletion of 383 bp in a gene (at chromosome 1) coding for one of the enzymes encoded by GA20-oxidase gene (GA20ox2), catalysing the synthesis of bioactive GA 3 . Out of several compounds responsible for aroma in rice, a highly volatile 2- acetyl-1-pyrroline (2-AP) is the principal component 4 detected in all aerial plant parts of scented rice 5 . The semi-dwarf plant height and fragrance in rice is governed by recessive genes sd1 and badh2, respectively and their presence can only be determined phenotypically by the final height of the plant after the flowering or late developmental stages. The DNA markers for these traits are widely used in rice improvement by marker-assisted selection (MAS) which has helped breeders to identify and eliminate the plants in early generation 6-7 . To reduce the height and maturity period, a marker assisted breeding (MAB) programme was initiated by crossing Katarni with three semi-dwarf rice varieties namely Rajendra Sweta, IR64 and MTU7029. Testing —————— *Author for correspondence: mankesh2008@gmail.com, mankesh_srivastava@rediffmail.com Mobile phone: +91-9771602414 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by NOPR