Comparison of S2 and S2 X test cross evaluation for the selection in maize

Abstract

S2 and S2 1testcross hybrid evaluation for one cycle of selection for resistance to the spotted stem borer, (Chilo partellus Swinhoe) and grain yield were made in an open-pollinated maize (Zea mays L) population (ICZ3) One hundred forty four S2 lines and 140 S2 testeross hybrids were evaluated and selected at 10 percent intensity percent gains for single trait selections ranged from 67 18 percent to 31 40 percent for dead heart and 7 90 percent to 23 21 percent for grain yield of the S2 testcross hybnds, respectively For the aggregate trait, gains per cycle (percent) ranged from 96 01 percent to 48 45 percent for dead heart and 2 90 percent to 2745percent for stem tunnelling for the S2 testcross hybrids, respectively Predicted direct responses (iXglcycle) to aggregate trait selections for both the grain yield and parameters of resistance showed no significant differences for the two evaluation methods except for stem …