Phenotypic stability and homeostasis in Assam rice landraces at varying nitrogen regimes

ABSTRACT

Aim: The present study was designed to identify stable rice (Oryza sativa L.) genotypes for nitrogen use efficiency (NUE), yield and its component traits and also to identify component traits associated with yield stability. Methodology: Twenty-one landraces along with five high yielding varieties (HYVs) of rice were evaluated at three nitrogen levels (0, 40 and 60 kg N ha-1) for two years (2014 and 2015). Eberhart and Russel’s (1966) stability analysis were employed to assess the genotype × environment (GE) interaction and the stability of the genotypes across six environments. To study homeostasis, simple correlation analysis among ten different traits was done based on stability parameters. Results: The present study revealed that environments created by graded nitrogen levels were fruitful for inducing environmental variations. The highly significant linear environmental variances were found for all ten traits. Linear GE interaction was significant for all the traits, except harvest index, grain nitrogen and nitrogen harvest index. The stability analysis identified four genotypes viz., Kolabor, Aki Bora, Rongdoi and Luha Sali with average stability whereas Betguti Sali was found to be stable below average. Correlation analysis based on stability parameters revealed the existence of homeostasis. Interpretation: Present study revealed that genotypes namely Kolabor, Aki Bora, Rongdoi and Luha Sali are suitable to grow under both nitrogen limiting and nitrogen non-limiting environments whereas Betguti Sali was suitable for nitrogen non-limiting environments. Correlation analysis, based on stability parameters, revealed that yield stability was due to the plasticity of some other component traits under study.