COMPARATIVE STUDY OF RECIPROCAL CROSSING FOR ESTABLISHMENT OF <em>ACACIA</em> HYBRIDS

Abstract

KATO K, YAMAGUCHI S, CHIGIRA O & HANAOKA S. 2013. Comparative study of reciprocal crossing for establishment of Acacia hybrids. Using two Acacia mangium and five A. auriculiformis clones, Acacia hybrids were reciprocally artificially pollinated by tube pollination to determine which cross combination was more appropriate. Artificial pollination was also conducted on the intraspecific pollination of each clone. Pollen germination percentage and number of flowers for each clone were also investigated. The pollen germination percentage showed significant difference between the clones but no significant difference between species. The number of flowers per spike on A. mangium was almost double that on A. auriculiformis, but this difference did not affect the productivity of seeds. Although seed productivity was not different between reciprocal crossings, number of mature seeds, seed germination percentage and number of seedlings acquired were significantly higher when A. mangium was used as the female adult and also varied greatly among cross combinations. Seed productivity was also low on the intraspecific pollination of A. auriculiformis. By DNA analysis, 0.9% of seedlings produced by interspecific pollination were not hybrid. From these results, we suggested that three points for breeding programme of Acacia hybrids, namely, availability of each reciprocal crossing, caution for using A. auriculiformis clones in interspecific pollination and possibility of self-compatibility by tube pollination.