Ann. Bot. Fennici 48: 317–324 ISSN 0003-3847 (print) ISSN 1797-2442 (online) Helsinki 30 August 2011 © Finnish Zoological and Botanical Publishing Board 2011 Nymphaea alba var. rubra is a hybrid of N. alba and N. odorata as evidenced by molecular analysis Jeremy Dkhar, Suman Kumaria* & Pramod Tandon Plant Biotechnology Laboratory, Centre for Advanced Studies in Botany, North Eastern Hill University, Shillong 793 022, India (*corresponding author’s e-mail: sumankhatrikumaria@hotmail.com) Received 25 Feb. 2010, revised version received 31 Mar. 2010, accepted 20 Apr. 2010 Dkhar, J., Kumaria, S. & Tandon, P. 2011: Nymphaea alba var. rubra is a hybrid of N. alba and N. odorata as evidenced by molecular analysis. — Ann. Bot. Fennici 48: 317–324. Sequencing signals of the biparentally inherited ITS marker and sequence matching of the chloroplast trnK intron, matK and rbcL gene of an Indian plant identiied as Nym- phaea alba var. rubra contradict its identity. Additional signals depicted in chromato- grams of the ITS region and the exact match of the maternally inherited chloroplast DNA sequences suggest that the Indian material is a hybrid of N. alba and N. odorata. Molecular cloning techniques resulted in the isolation of ITS alleles from the puta- tive hybrid with DNA sequences not exclusive of either of the parental species. Such allelic DNA sequences conirmed that hybridization between N. alba and N. odorata has occurred. Our DNA sequence analyses indicate this plant is an interspeciic hybrid involving N. odorata as the maternal parent, and N. alba as the paternal parent. Introduction Anomalies in the identiication of waterlily hybrids and cultivars have instigated the Inter- national Waterlily and Water Gardening Society (www.iwgs.org) to initiate a programme directed at providing a complete account of cultivated Nymphaea. However, the dificulty that exists in conclusively documenting waterlily hybrids and the reluctance of hybridizers to divulge explicit data on the methodology and parentages (Conard 1905, Swindells 1983, Les & Philbrick 1993) would be a setback in the successful com- pletion of this project. In certain cases, some plant hybridizers provide precise documented manipulations relying exclusively on morpho- logical features in determining parental charac- teristics in suspected hybrid plants (e.g. Pring 1934a, 1934b). More recently, plant researchers (Moody & Les 2002, Les et al. 2004) presented explicit documentation of hybrids using molecu- lar markers. The approach of identifying hybrids morphologically is troublesome because hybrids can exhibit features that are purely a parental mixture, intermediary or novel (Conard 1905, Rieseberg 1995, Les et al. 2004). However, with the advent of genetic markers, it has become fea- sible for demonstrating genetic contributions of different parental genotypes in suspected hybrid plants. Co-existence of the nrDNA repeats from both parents in the putative hybrids provides useful means of identifying parental species (Peterson et al. 2004, Saito et al. 2007), whereas chloroplast DNA can assist in recognizing the direction of hybridization (Albarouki & Peter- son 2007). Evidence of hybridization employing both nuclear and chloroplast markers have been reported in species of Nuphar (Padgett et al.