Development and validation of microsatellite markers linked to the rice blast resistance gene Pi-z of Fukunishiki and Zenith
- 163 Downloads
Rice blast resistance gene ‘Pi-z’ present in rice genotypes, Zenith and Fukunishiki, represents a potential source of blast resistance for the north-western Himalayan region of India. We tested the reliability of microsatellite markers linked to Pi-z for assessing blast resistance phenotype in crosses of commercial importance. A new set of microsatellite markers linked to Pi-z was also developed by exploiting the publicly available marker and genomic resources of rice. Of the three previously reported markers for Pi-z, only MRG5836 was suitable for the marker assisted selection of Pi-z. Among the 17 microsatellites selected from the putative region of Pi-z locus, two, RM8225 and RM8226 cosegregated with MRG5836 and were located at distance of 1.2–4.5 cM from the gene. A new microsatellite marker ‘SSR236’ was developed from the (CT)16 repeat of PAC clone P0502B12, which exhibited closer linkage (0.6–1.2 cM) to Pi-z. Survey of the allelic diversity at the loci of the Pi-z linked microsatellite markers revealed that the Fukunishiki and Zenith type alleles were not present in majority of the local indica rice genotypes. As these markers are polymorphic between the Pi-z donors and a great majority of local indica rices tested, they can be used as a selection tool in rice breeding programs aimed at improving the blast resistance of local rices.
KeywordsMicrosatellite markers Pi-z gene Resistance Rice blast
The authors wish to thank the Program Director, Advanced Centre of Hill Bioresources and Biotechnology, H.P. Agricultural University, Palampur for providing all the necessary facilities for this work. The Financial assistance received from the Department of Biotechnology, Govt. of India is also duly acknowledged.
- Ezuka A, Yunoki T, Sakurai H, Shinoda H, Toriyamo K (1969) Studies on the varietal resistance of rice to blast II. Tests for genotype of “true resistance”. Bull Chugoku Natl Agric Exp Stn E4:1–30Google Scholar
- Katoch PC, Kaushik RP, Sharma SL, Sharma BD (2004) Genetic improvement of rice varieties in Himachal Pradesh. In: Sharma SD, Rao UP (eds) Genetic improvement of rice varities of India. Today & Tomorrow’s Printers and Publishers, New Delhi, pp 551–579Google Scholar
- Kiyosawa S (1967) The inheritance of resistance of Zenith type varieties of rice to the blast fungus. Jap J Breed 17:99–107Google Scholar
- Kosambi DD (1944) The estimation of map distances from recombination values. Ann Eugen 12:172–175Google Scholar
- McCouch SR (2002) Development and mapping of 2240 new SSR markers for rice (Oryza sativa L.). DNA Res 9:193–207Google Scholar
- Rathour R, Singh BM, Plaha P (2006) Virulence structure of Magnaporthe grisea rice population from north-western Himalayas. Phytoparastica 34:281–291Google Scholar
- Wu J, Jiang J, Chen H, Wang S (2002) Fine mapping of rice blast resistance gene Pi-2(t). Acta Agronimica Sinica 28:505–509Google Scholar
- Zhou B, Qu S, Liu G, Dolan M, Sakai H, Lu G, Bellizzi M, Wang GL (2006) The eight amino acid differences within three leucine-rich repeats between Pi2 and Piz-t resistance proteins determine the resistance specificity to Magnaporthe grisea. Mol Plant Microbe Interact 19:1216–1228PubMedCrossRefGoogle Scholar