Characterization of provenances for the development of base-population of Eucalyptus camaldulensis Debn

Author(s)

Izabel Christina Gava de Souza

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 1996-03-06
• Advisor: Mario Ferreira

Abstract

The aim of this work was to select base-populations of Eucalyptus camaldulensis for the production of seeds and to provide maintenance for the species breeding by studying intra-specific variation (Inter-and intraprovenance of seeds) regarding silvicultural characteristics, morphological characteristics of both leaf and fruit, flowering phenology, and seed viability (number of viable seeds/kg). Two provenance tests located in Anhembi (SP) were evaluated with lots containing seeds from states of northern Australia-Queensland (QLD), Western Australia (WA), and North Territory (NT) - latitude ranging from 14°30' to 19°34', longitude from 124°45' to 145°09', and altitude from 30 to 680 meters. Such tests were evaluated at 9.5 and 8.5 years of age for silvicultural characteristics and morphological characteristics of both and adult young leaves. Studies on blooming phenology, morphological characteristics of fruit, and seed viability were accomplished in an arboretum of provenances also located in Anhembi. The blooming phenology was perfomed throughout a 2 year period for periodicity and intensity of flower presence. In addition, the presence of floral buds and fruit was verified. In order to evaluate flower intensity and floral budding indexes such as flower index and bud index, respectively, were elaborated. The lots from Queensland and North Territory were observed lo present best silvicultural behavior in relationship with lots from Western Australia. The morphological evaluation of leaves did not distinguish the studied provenances. As to the fruit morphology, the multivariate analysis separated lot 12181 from North Territory. The study on phenology showed variations concerning periods and intensity of presence of floral buds, flower, and fruit within and among the studied provenances. The Queensland lots presented two blooming patterns and those from Western Australia four patterns. The average flower indexes obtained per provenance QLD, WA, and NT were, respectively, 0.62, 0.17, and 0.32. Lot 0574 from WA failed to bloom in Anhembi. The study proved to play an important part in the planning of populations in order to provide higher recombination of genetical material out to the desired population. The flower indexes obtained presented positive and significant correlation with longitude, thus showing that the highest blooming potential for Anhembi is associated to the lots from Queensland. The individual (among and within provenances) variation in number of seeds/kg was observed to be great, where individuals presented 10,690 to 3,116,810 viable seeds/kg. Such great variation proves the importance of seed viability evaluation for the planning of base-populations, therefore suggesting that individuals with low numbers of viable seeds/kg should be avoided in the formation of base-populations. Positive and significant correlations were found among seed viability, flower index, and longitude. Queensland, North Territory, and Western Australia provenances presented average values for flower indexes and number of viable seeds/kg, respectively, 0.62 and 927,200, 0,32 and 410,200 and 0.17 and 312,890. According to the studied variables, the clustering of seed lots was suggested as an endeavor to allow higher genetical material recombination to obtain seeds representing the desidered population. In that sense, base-populations are suggested as follows: Base-population I - Katherine region (NT): formed by lot 12181; Base population II - Burdekin and Petford region (QLD): formed by lots 12185, 12186, 12187, 12510, CAF, 12962, 12964, and 12968; Base population III - Gilbert River region (QLD); formed by lots 10923, 10924 and 12963; Base population IV - Kimberley region (WA): formed by lots 10557, 12349, 12350 and 12352. (AU)