www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 14.139.212.5 on dated 16-Apr-2012 Indian J. Genet., 71(3): 209-213 (2011) Abstract Phosphorous (P) fixation in soils with high free ferric oxides and aluminum in the clay fraction is a widespread problem and limits access of plants to P even if it is present in the soil. Problem is acute in upland situation. Therefore, a set of 31 rice genotypes comprising of adopted upland and lowland lines as well as aromatic and semi-dwarf high yielding cultivars were grown both in P-deficient as well as P-sufficient soil. P-uptake ability of these genotypes was compared when they were grown in P-sufficient as well as in P-deficient soil. Six genotypes (Gitanjali, Gobindabhog, Jaladhi, Pusa Saugandh, Radhunipagol, Tulaipanji) accumulated significantly more P per plant under both P- sufficient (p < 0.01) and P-deficient (p < 0.01) conditions. Rice genotypes were also characterized by PCR-based markers, Pup-1 K42 and Pup-1 K29 which were linked with a major QTL for phosphate uptake-1 ( Pup-1) locus. Haplotyping of Pup-1-K42 markers showed 918 bp amplification in nine genotypes but among them, only three genotypes showed higher P-uptake and dry-matter -weight in P-limiting condition. Unlike japonica germplasm, both K42 and K29 were not diagnostics in assessing Pup-1 locus in indica germplasm. Three Bengal landraces, Bhutmuri, Gobindabhog and Radhunipagol can serve as ideal donor parent for introgression of Pup1 locus. The markers validated in this study will help in the marker assisted introgression of P-deficiency tolerance in rice. Key words: P-deficient, rice Pup-1, MAS, Bengal land race Introduction Approximately sixty percent rainfed rice in Asia is grown on soils affected by multiple stresses and one of them is Phosphorus (P) deficiency [1]. Phosphorus is one of the least available of all essential nutrients in the soil and its concentration is generally below that of many other micronutrients [2]. A high content of free ferric oxides and high aluminium (Al) limit the P availability to plants even when present in the soil and has become a widespread problem. Although the application of P fertilizer can rectify the problem to some extent, it is expensive for the marginal rice growers and results in eutrophication. Thus selection of rice cultivars which can extract Phosphorus from P-limiting soils, which have a higher P fertilizer use efficiency, is therefore considered an important cost- effective management. Wissuwa et al. [3] identified QTLs for P deficiency tolerance in rice which mainly confers increased P uptake (Pup-1). A major QTL for P-uptake was mapped on chromosome 12 with additional minor QTLs on chromosome 2, 6 and 10. Though substitution mapping by Wissuwa et al. [4], it was found that the Pup-1 on chromosome 12 alone explains more than 70 % of total variability. Pup-1, locus increases P-uptake under adverse conditions rather than increasing internal P-use efficiency [5]. Due to lack of polymorphic SSR markers surrounding the Pup-1 locus, marker assisted introgression of this locus was not easy [6]. Recently, Chin et al. [7] reported that the Pup-1 locus-specific genomic sequence of the rice genotype Kasalath (tolerant to P-deficiency) is located in large insertion-deletion (INDEL) region, which is absent in P-deficient-susceptible genotype Nipponbare. They have also recommended number of PCR based markers derived from the sequence polymorphic between Kasalath and Nipponbare [7]. *Corresponding author’s e-mail: somnathbhat@yahoo.com Published by Indian Society of Genetics & Plant Breeding, F2, First Floor, NASC Complex, PB#11312, IARI, New Delhi 110 012 Online management by indianjournals.com Screening for phosphorus(P) tolerance and validation of Pup-1 linked markers in indica rice Sutanu Sarkar, Roshan Yelne, Mitali Chatterjee, Padminee Das, Sandip Debnath, Asish Chakraborty 1 , Nirmal Mandal, Kallol Bhattacharya 2 and Somnath Bhattacharyya* 1 Department of Genetics and Biotechnology, Regional Research Substation for Red and Lateritic Zone, Sekhampur, Birbhum, West Bengal; 2 Agriculture Chemistry and Soil Science; Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal 741 252 (Received: October 2010; Revised: May 2011; Accepted: July 2011)