Linkage relationships between blast resistance and certain morphological of physiological characters in rice

Eight rice genetic stocks with characters of waxiness, chromogen, dripping wet, ligulelessness, laziness, brittle culm, glabrousness, and long hairiness on leaf surface, were crossed to a rice line IR1905-81-3-1, which was normal for these morphological or physiological characters. The eight genetic stocks were susceptible to Pyricularia oryzae races IB-47 (isolate P06-6), IH-1 (isolate 43), and II-1 (isolate 43-1), while IR1905-81-3-1 was resistant to these races. Inheritance of resistance to blast and linkage relationships between blast resistance and the characters were studied in the F₂ populations. The resistance of the rice cultivar IR1905-81-3-1 to blast fungus races IB-47 and II-1 was controlled by one dominant gene each, and the resistance to race IH-1 by two dominant genes. No linkage relationships were found between the resistance of IR1905-81-3-1 to race IB-47 and the characters waxiness, chromogen, dripping-wet (lack of wax on leaf surface), ligulelessness, laziness, brittle culm (lack of α-cellulose in cell wall), glabrousness, and long hairiness on leaf surface. There were no linkages between the resistance to race IH-1 and waxiness, chromogen, ligulelessness, brittle culm. and glaborusness, and between the resistance to race II-1 and chromogen, dripping-wet, and brittle culm. However, loose linkage relationship was found between the resistance of IR1905-81-3-1 to the blast race IH-1 and laziness.