Controlled pollination studies with shining gum (Eucalyptus nitens (Deane & Maiden) Maiden)

• Published in: Forestry (London) 1989, Vol.62 (2), p.111-126
• Main Author: Tibbits, W.N
• Format: Article
• Language: English
• Subjects: Eucalyptus nitens; flowering; heritability; interspecific controlled pollination; intraspecific controlled pollination; pollination; provenance; seed production
• ISSN: 0015-752X; 1464-3626
• DOI: 10.1093/forestry/62.2.111

Intraspecific and interspecific controlled pollinations were attempted on 12 E. nitens trees representing a range of provenances. Over consecutive flowering seasons there were consistent differences in the relative flowering times of five genotypes on one site. Of 24 intraspecific combinations attempted in 1985 62 per cent set seed, and overall 45 per cent of flowers pollinated set seed. All but one of 10 interspecific combinations succeeded with 33 per cent of flowers pollinated setting seed. The maternal influence was generally stronger than the paternal, in terms of number of seed set and seed weight. For all mothers, the mean number of seeds per capsule from self-pollinated and open-pollinated flowers were only 2.2 and 3.8, compared with 6.8 and 7.9 for flowers hand-pollinated with E. gunnii and E. nitens pollen respectively. Implications of various aspects of the reproductive biology of these species on breeding programmes are discussed. Two previously identified forms of E. nitens showed consistent differences in floral morphology, flowering time and seed maturity. Their taxonomic status is commented on.