Evaluation of Recurrent Selection for Specific Combining Ability in Two Open‐pollinated Maize Cultivars¹

Abstract

We evaluated recurrent selection for specific combining ability in two open‐pollinated maize (Zea mays L.) cultivars, ‘Kolkmeier’ and ‘Lancaster’. A common, singlecross tester, WF9 ✕ Hy, was used in the first cycle, but inbred Hy was used in the four subsequent cycles. The principal basis of selection was grain yield of half‐sib progenies. Progress for population improvement was evaluated in five environments by measuring yields in the Kolkmeier and Lancaster populations per se, the Hy ✕ Kolkmeier Cn (n = 0, 1,2 …, 5) and Hy ✕ Lancaster Cn test‐crosses, the Kolkmeier Cn ✕ Lancaster C. population crosses, and the Cn and C5 populations of both cuitivars in crosses with Alph C0, Alph C5, BI4A, B73, and Mo17. Kolkmeier per se did not show a significant change in yield; Lancaster per se, however, had a significant negative linear trend, −0.95 ± 0.45 q/ha/cycle. The rates of yield gain (q/ha) for Hy ✕ Kolkmeier Cn and Hy ✕ Lancaster Cn were 2.75 ± 0.45 and 2.23 ± 0.45, respectively. The rate of yield gain (q/ha) for Kolkmeier Cn ✕ Lancaster Cn was linear and significant, 2.45 ± 0.45. Similar yield gains were expressed with the C0 and C5 populations in testcrosses with other unrelated testers, except B73 for which there were no differences between testcrosses of the C0 and C5 populations. The recurrent selection program has been successful in increasing frequencies of genes with favorable yield effects in crosses, and overdominance was relatively unimportant in the change in yield potential of the two cultivars. Recurrent selection by using an inbred line tester seems to be an efficient method to improve breeding populations. The obvious tester would be a line that is already widely used in the seed industry. As the program progresses, this line can be replaced by a better line with no deleterious results relative to the population improvement achieved by the earlier tester.

Heterozygous genotypes are efficient testers for assessing between-population combining ability in the reciprocal recurrent selection of Coffea canephora

“…Gallais (1978) proposed that the tester needed not be a fixed line but (i) it must have a good inherent value and a good value when combined with the reciprocal population and (ii) it must effectively reveal the genetic variability of the reciprocal population. Initial studies showed advantages of RRSi with fixed lines over RRS: greater genetic variance between the test crosses (Darrah et al 1972;Horner et al 1973) and equivalent or greater genetic gains (Horner et al 1973;Russell et al 1973;Walejko and Russell 1977;Zambezi et al 1986;Landi and Frascaroli1995). However, two other studies compared the genetic progress achieved with RRS and RRSi from the same base populations and concluded that RRS was better than RRSi (Russell et al 1992;Menz Rademacher et al 1999).…”

Comparison of half-sib and S1 recurrent selection in 'Krug Yellow Dent'

“…Other reports have shown the same results. By using an inbred tester, selection was for specific combining ability (SCA) as well as for general combining ability (GCA) as measured in the performance of the population per se and in crosses with other populations (Russell and Eberhart, 1975;Walejko and Russell, 1977). Hoegemeyer and Hallauer (1976) showed that reciprocal full sib selection in BSIO and BSll was effective for SCA, but that selection for GCA effects was more important.…”

Evaluation of three recurrent selection methods in corn (Zea mays L.)

“…Walejko and Russell (1977) evaluated the use of a narrow-based tester to improve two com populations for grain yield. They reported that progress for yield was primarily due to improved general combining ability and that an inbred line could be an effective tester for increasing general combining ability.…”