Assessment of Morphological Diversity within Wild Rice (Oryza rufi pogon Griff.) Germplasm of NBU Campus (West Bengal) for In Situ Conservation – A Case Study

Abstract

Natural population of Oryza rufi pogon Griff. in the North Bengal University campus was characterized based on phylogeographic and morphological parameters for conservation purposes. Twenty-six different morphological characters were considered for genetic relatedness analysis within the population. Diagnostic characters were provided to delineate the species morphologically. Plants were annual ecotype having short to intermediate culm height (64-145 cm), and 0.5-1.6 cm thickness. Profuse fi brous roots of 2 mm thick and 3-9 cm long creamy-white colour emerged from the fl oating nodes, that was solid and pinkish (5-7 mm long). Flag leaf length ranged from 13-40 cm and 0.3-1.8 cm in width. Flag leaf blade attitude varied from defl exed to horizontal to semierect. Auricle was hard, curved, glabrous and 13-15.5 mm. Two-cleft ligule length ranged 17-35 mm. Panicle length varied from 15.4-30 cm with 1-8 cm wide with 5-13 primary branches. Attitude of primary branches was spreading, well-exserted (100%), alternately arranged on the wavy axis. Length of the lemma varies 6-11 mm and 1.4-2.3 mm wide, lemma-awn junction marked by a pinkish pubescent constriction with 23-80 mm long red awn. Yellow colour anthers varied in length 4-8 mm long. Stigma was bifurcated (> 2 mm) and purple comes out from the spikelets. Seeds (blackish) varied in length (7.5-10 mm). Density of fertile spikelets ranged from 15-82. Grain length/breadth ratio was 3.73 and average kernel length/breadth ratio was 3.99. The results suggested that the studied population were genetically diversifi ed, heterogeneous and should be conserved in situ to protect precious genetic resource as separate ecological race (ecotype or intergrade) for germplasm enhancement.