SHENOY, V. V.SHENOY, V. V.GURUDATTA, B. V.GURUDATTA, B. V.2019-10-192019-10-192001-08-072001-08-07Th-5966Th-5966http://krishikosh.egranth.ac.in/handle/1/5810132150An investigation was carried out to study the inheritance of paranodulation in rainfed upland rice. The genotypes Hakkalasali and Gopal Dodiga were used as high paranodulating parents and Rasi was the low paranoduiating parent in two low X high paranodulation crosses, viz., Rasi X Hakkalasali and Rasi X Gopal Dodiga. The Fi, F2 and parents were studied for paranodules per seedling, root length, shoot length, root:shoot ratio, seedling length and seedling dry weight. The high paranodulating parents had significantly higher mean paranodulation over the low paranodulating parent indicating that the parents were distinct for the trait. There were no perceptible differences for isozymes GDH and POX between the parents. Positive heterosis was observed for all the observed traits. The paranodulation in F2 showed discrete distribution exhibiting a significant goodness to fit with 9 low: 7 high paranodulating types indicating operation of digenic complementary interaction (duplicate recessive epistasis) in the genetic regulation of paranodulation. At the individual loci, low paranodulation was dominant over the high paranodulation, whereas, between the loci, high paranodulation was epistatic over the low.It is proposed to designate the loci as Pnodl and Pnod2. exhibiting complementary digenic interaction. The variable pattern of association of seedling traits witli paranodulation in the two crosses indicated that the traits can not be used as markers for paranodulation, except for root:shoot ratio. The low root:shoot ratio resulted in higher paranodulation. The study involving seven high paranodulating genotypes indicated that Azospirillum strain ACD15 was superior to ACD20 for colonisation of paranodules, because it colonised in all the seven genotypes, but the latter colonised in only five. The Rhizobium strain NC92 showed colonisation in genotypes Champakali and Hakkalasali, also indicating that rhizobia can succeed in colonisation of rice paranodules in a genotype dependent manner.An investigation was carried out to study the inheritance of paranodulation in rainfed upland rice. The genotypes Hakkalasali and Gopal Dodiga were used as high paranodulating parents and Rasi was the low paranoduiating parent in two low X high paranodulation crosses, viz., Rasi X Hakkalasali and Rasi X Gopal Dodiga. The Fi, F2 and parents were studied for paranodules per seedling, root length, shoot length, root:shoot ratio, seedling length and seedling dry weight. The high paranodulating parents had significantly higher mean paranodulation over the low paranodulating parent indicating that the parents were distinct for the trait. There were no perceptible differences for isozymes GDH and POX between the parents. Positive heterosis was observed for all the observed traits. The paranodulation in F2 showed discrete distribution exhibiting a significant goodness to fit with 9 low: 7 high paranodulating types indicating operation of digenic complementary interaction (duplicate recessive epistasis) in the genetic regulation of paranodulation. At the individual loci, low paranodulation was dominant over the high paranodulation, whereas, between the loci, high paranodulation was epistatic over the low.It is proposed to designate the loci as Pnodl and Pnod2. exhibiting complementary digenic interaction. The variable pattern of association of seedling traits witli paranodulation in the two crosses indicated that the traits can not be used as markers for paranodulation, except for root:shoot ratio. The low root:shoot ratio resulted in higher paranodulation. The study involving seven high paranodulating genotypes indicated that Azospirillum strain ACD15 was superior to ACD20 for colonisation of paranodules, because it colonised in all the seven genotypes, but the latter colonised in only five. The Rhizobium strain NC92 showed colonisation in genotypes Champakali and Hakkalasali, also indicating that rhizobia can succeed in colonisation of rice paranodules in a genotype dependent manner.ennullnullThesis