Gains Expected from Clonal Orchards under Alternative Breeding Strategies

Washington D.C.

1989

S. 183-196

3 Tab., 1 Anh., 18 Lit. Ang.

Bandaufführung

7380

16198

Gain equations were developed under the assumption of an additive genetic model and were used to calculate responses from clonal seed orchard under six strategies for breeding trees. The six strategies involve combinations of phenotypic or combined index selection to establish orchards, and polycross, singe-pair, or half-diallel mating for progeny testing to cull orchards and for regenerating the breeding population. Open-pollinated mating was considered for progeny testing only. Combined index selection with half-diallel mating produced the greatest gains from orchards. Single- pair mating used in conjunction with open-pollinated progeny testing proved to be the next best option under the range of heritabilities studied (heritabilities from 0.05 to 0.6). However, combined index selection with single-pair mating (and no open-pollinated testing) was also very efficient. Combined index selection with polycross mating produced substantial gains from culled orchards but was less appealing for unculled orchards.