GENETICS AND PHENOTYPIC STABILITY ANALYSIS OF RESISTANCE TO THE BROWN PLANTHOPPER IN RICE VARIETIES

The genetics of resistance to the brown planthopper (BPH), Nilaparvotc lugens(Stal) was studied in 15 rice varieties. The resistance of ' Guomeizhan' was controlled by one recessive gene'. BG 367 - 4'possesed two recessive genes for the resistance . A single dominant genes conditioned the resistance in 'Sanguizhan 1' ,'Suweon 294' ,'KAU 1727','IR 13539-100-2-2-2-3','IR 7149-5-2-1-1'and'IR 13240-108-2-2-3'.Two dominant genes conveyed the resistance in 'IR25586-108-1-2-2-2'.The resistance in 'Sanhuangzhan 2' ,'Sanyezhan 1' ,'Tieliuxuan 2','Xinhuizhan 1','GENG 77-4' and 'IR 13427-40-2-3-3'was governed by one dominant and one recessive gene.Stability of resistance of 12 rice varieties with different resistant levels in seedling stage was studied. The parameters of genetypic stability of resistance were estimated by the method proposed by Tai (1971) . The results indicated that the varieties showed different levels of resistant stability. The variety of 'TN 1' was a susceptible variety with very high stability.'IR 25586-108-1-2-2-2' ,'BG 367-4' and'Mudgo' were resistant varieties with high stability. The resistance of ' Sanyezhan 1' ,' Sanguizhan 1' and ' Tieliuxuan' exhibited moderate stability, while resistance in the resistant varieties ' Guomeizhan' ,' Sanhuangzhan 2' ,' Suweon 294' and the moderately resistant varieties ' Fubaoai 21' and ' Baoxuan 2' was unstable.