Abstract

Bulk seedlots of two unpedigreed multiprovenance seed production areas (SPAs) each of Eucalyptus camaldulensis and Eucalyptus tereticornis and one pedigreed seedling seed orchard (SSO) of E. tereticornis were planted in genetic gain trials at three southern Indian trial sites. At the time of seed collection, fewer than 30% trees flowered in these orchards, except in one E. camaldulensis SPA where 73% of the trees flowered, which had an estimated outcrossing rate of 86%. The E. tereticornis SSO was dominated by pollen from five highly fecund families of the Indian Mysore gum land race, which contributed 59% of the fruits produced. The SPA and SSO seedlots were compared with a bulked natural-provenance seedlot of E. camaldulensis (Morehead, Laura, and Kennedy Rivers, Queensland), another natural-provenance seedlot (Petford, Queensland), commercial eucalypt clones at two sites, and a Mysore gum seedlot at one site. At 3 years, progeny from all the four SPAs displayed good survival (79-93%) and performance similar to that of the natural provenances and the commercial clones. Progeny from the E. tereticornis SSO had significantly lower growth (at two sites) and lower survival at all three test sites. The Mysore gum seedlot displayed high fecundity and lower growth but better survival than the SSO progeny. Seed orchard genetic composition and flowering contributions thus affected progeny performance and the extent to which orchard genetic diversity was captured in the progeny. SPA progeny displayed greater fecundity than the natural provenances, indicating a response to selection for fertility.

Keywords

Domestication; Fertility; Seed orchard; Eucalyptus camaldulensis; E. tereticornis

Published in

Tree Genetics and Genomes
2009, volume: 5, number: 4, pages: 629-640

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