The data presented below are courtesy of Dr. R. Kumar of Indira Gandhi Agricultural University (IGAU), at Raipur in Chhattisgarh, a drought-prone state in eastern India.  147 unselected recombinant inbred lines were evaluated under severe terminal lowland drought stress in replicated trials, as well as in fully irrigated non-stress controls.  

 

Data reported are for the combined analysis of two years (2000 and 2002) in which severe drought stress was experienced.  Root traits are thought to be associated with drought tolerance, so two traits related to root system size, root-pulling resistance (RPR) and root biomass at flowering (RBF) were measured in the non-stress control treatment.  H for these traits and for yield in the irrigated control, as well as their rG with stress yield, are presented in the table below:

 

Table: H for yield and root traits in irrigated control, and correlation with yield under stress: Raipur 2000 and 2002

 

 

 

Neither of the root traits were highly correlated with yield under stress, and the repeatability of their measurement was quite low.  H for the target trait itself, yield under stress, was estimated to be 0.37 of a single 3-replicate trial.  The indirect response in stress yield resulting from selection for each of the traits measured in the non-stress trial, relative to direct response to selection for yield under stress, was estimated using .  

 

In no case did it exceed 1.0, so none of the traits are more efficient selection criteria than direct selection for yield under stress.