Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

increased response for grain yield.
in all respects in BSSS and BSCB1.
Eleven cycles of half-sib recurrent selection were effective
Table 7. Responses to 11 cycles of half-sib reciprocal recurrent selection conducted in BSSS and
BSCB1 (Adapted from Keerati n i j aka1 and Lamkey, 1993).
Cycles of Grain yield (q/ha) Grain moisture (';) Stalk lodging (,.)
selection BSSS Cross BSCB1 BSSS Cross BSCBT BSSS Cross BSCB1
CO 35.5 42.4 32.1 21 19 18 20 25 40
C4 37.6 49.4 31.6 19 18 17 21 30 32
C7 42.4 60.8 36.1 21 20 20 17 20 18
C8 43.4 65.9 33.0 21 20 20 14 14 12
C9 42.5 69.4 38.7 21 19 19 16 15 10
C10 39.8 68.4 35.9 20 19 19 17 16 12
C11 39.2 67.6 37.6 22 19 19 10 11 10
b 0.6 2.8 0.6 0.0 0.0 0.0 -0.6 -1.5 -3.1
Change, ,.+ 10.4 59.4 17 .1 4.8 0.0 5.6 -50.0 -56.0 -66.7
t Change of C11
relative to CO.
Reciprocal recurrent selection based on full-sib progenies was initiated in 1964 with 8510
and 8511 populations. This selection program also is being continued with 11 cycles of selection
completed. Responses to selection were determined by Eyherabide and Hallauer (1991) after eight
cycles of selection (Table 8). Direct response in the population crosses was 60.4'; with an
average increase of 3.1 q/ha per cycle of selection. Midparent heterosis for grain yield
increased from 2.4" (CO x CO) to 4O.~ (ca x ca). Indirect response for grain yielding 8510
(23.6X) and 8511 (13.0,;) also was realized. Other agronomic traits also were considered in
Table 8. Responses to eight cycles of full-sib reciprocal recurrent selection conducted in 8510
and 8511 (Adapted from Eyherabide and Hallauer, 1991).
Cycles of
selection
Grain yield (g/ha)
8510 Cross 8511
Grain moisture (~) Stalk lodging (~)
8510 Cross 8511 8510 Cross 8511
co 41.5 46.5 49.2 20 21 22 22 21 22
C2 43.8 57.2 51.5 17 19 20 24 20 16
C4 50.9 59.6 48.6 19 19 20 19 18 16
C6 52.4 63.6 54.7 21 20 19 13 15 12
C8 51.3 74.6 55.6 18 19 21 16 12 13
b 3.2 3.1 0.8 -0.1 -1.4 -1.0 -1.2 -1.1
Change, ~ 23.6 60.4 13.0 -10.0 -9.5 -4.5 -23.8 -47.8 -40.9
LSD (0.05) 4.4 1.0 5.3
Inbred (51) Generation
CO 24 26 22 19 20 21 19 19 14
C2 27 34 31 18 20 20 20 18 12
C4 29 36 29 18 20 20 19 14 13
C6 31 37 32 20 20 19 12 13 15
C8 34 43 34 18 20 21 13 11 10
b 1.3 1.9 1.4 -0.1 -0.6 -1.0 -1.0
Change, ,,+ 41.7 65.4 54.6 -5.2 0.0 0.0 -31.6 -42.1 -28.6
LSD (0.05) 3.9 1.1 4.5
t Change of C8 relative to CO.
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