Provenance variation and within-provenance genetic parameters in Eucalyptus urophylla across 125 test sites in Brazil, Colombia, Mexico, South Africa and Venezuela

Abstract

Provenance and within-provenance genetic variation for stem volume growth in Eucalyptus urophylla was examined in a large trial series of 125 provenance/ progeny tests in five countries. In general, heritability (within-provenance) for age-3 volume was around 0.15 for Brazil, Colombia, Mexico, and South Africa and was slightly lower in Venezuela, where tree volume was lower. Provenances from all seven islands in Indonesia where the species occurs were included in the trials. Substantial provenance variation was observed in all countries, with the best provenances showing from 25 to 30 % more volume than the mean. The average of between-country genetic correlation estimates for growth traits was 0.72, both among and within provenances. Provenance and family performance between Mexico and Venezuela were very similar, with estimated provenance and withinprovenance genetic correlations of 1.00 and 0.90, respectively. There was some tendency for lower-elevation provenances to show better volume growth, but there were also very large differences observed between provenances located very close to one another. The results underscore the value of extensive provenance collections throughout the range of a species in order to ensure that the very best provenances are being captured.

Estimates of genetic parameters and genetic gains for growth traits of twoEucalyptus urophyllapopulations in Zululand, South Africa

“…Our results coincide with the relatively high type B correlations (above 0.55) reported by Wei and Borralho (1998), and Hodge and Dvorak (2015) for E. urophylla. Nirsatmanto et al (1996) reported moderate (0.49 for DBH) type B correlations between two sites in Indonesia, but indicated that predicted gains of the selection index across the sites were still greater than those of the indices at each site.…”

“…Various levels of GxE have been reported for E. urophylla (Mori et al 1990, Wei and Borralho 1998, Hodge and Dvorak 2015. Mori et al (1990) for example, have reported losses in volume of 26.7% due to GxE.…”

“…Eucalyptus urophylla is especially more tolerant to fungal diseases like Crysoporthe austroafricana and the Coniothyrium sp than pure E. grandis in Zululand (Retief and Stanger 2009). Generally, the E. grandis x E. urophylla hybrid has better disease tolerance and higher wood density than pure E. grandis (Retief andStanger 2009, Hodge andDvorak 2015). The current breeding strategy is to maintain and improve large breeding populations of both parental species in order to provide elite selections for hybrid crosses on a regular basis.…”

“…Some information on genetic parameters for growth traits of E. urophylla is available. In general, growth of E. urophylla has been reported to be under low to moderate genetic control with narrow-sense heritabilities ranging between 0.11 and 0.41 in China (Wei and Borralho 1998), 0.1 and 0.31 in Vietnam (Kien et al 2009), and 0.15 on average across 5 countries (Hodge and Dvorak 2015). However, the population structure and environmental factors of these studies are different to the ones in our study, and it's important to investigate the genetic parameters of E. urophylla in Zululand for hybrid breeding using this species.…”

Parâmetros genéticos para caracteres de crescimento, espessura de casca e densidade básica da madeira em progênies de Eucalyptus urophylla S.T. Blake

“…Entre as características favoráveis, destacam--se: alta taxa de crescimento, adaptação a diversas condições edafoclimáticas, boa capacidade de rebrota, resistência ao déficit hídrico e ao fungo causador da ferrugem (Puccinia psidii), a murcha do eucalipto (Ceratocystis fimbriata) e aos cancros do eucalipto (Chrysoporthe cubensis e Coniothyrium zuluense) (CARVALHO et al, 1998;FIRMINO et al, 2013;PALUDZYSZYN FILHO;PINTO et al, 2014); além de tolerância a vespa da galha (Leptocybe invasa) (THU et al, 2009). Em função disso, tem sido frequentemente utilizada para compor o híbrido com E. grandis, resultando em plantações clonais com melhor tolerância a doenças e maior densidade básica da madeira (HODGE;DVORAK, 2015). Em termos de empregabilidade, o E. urophylla pode ser utilizado na produção de celulose e papel, lenha e carvão vegetal, além da fabricação de postes, aglomerados e compensados (SELN;MITLÖHNER, 2011).…”