Factors affecting variation in outcrossing rate in Eucalyptus globulus

The mating system of the animal-pollinated forest tree species Eucalyptus globulus Labill. was investigated in a clonal seed orchard to determine the importance of self-incompatibility, floral timing, floral abundance and canopy position on explaining variation in outcrossing rates. Outcrossing rates were highly and significantly correlated with the degree of self-incompatibility of individual genotypes (R2 = 0.92). Outcrossing rates were also significantly higher in the upper than in the lower parts of tree canopies (0.78 ± 0.1 and 0.54 ± 0.1, respectively). In contrast, neither flowering time nor abundance of flowers on individual trees revealed consistent effects upon outcrossing rates, suggesting that these factors are either less important or inherently more unpredictable because their effects partly depend on complex interactions with animal pollinators. Screening seed orchards in order to identify trees with high self-incompatibility and restricting seed collection to these trees will ensure that a high proportion of the seed used for plantations is derived from outcrossing, thereby minimising the deleterious effects of inbreeding depression.

[1]  B. Potts,et al.  Pollinator activity can explain variation in outcrossing rates within individual trees , 2005 .

[2]  A. Charpentier.  Consequences of clonal growth for plant mating , 2001, Evolutionary Ecology.

[3]  B. Potts,et al.  Pollen competition does not affect the success of self-pollination in Eucalyptus globulus (Myrtaceae) , 2003 .

[4]  S. Gerber,et al.  Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis , 2003, Theoretical and Applied Genetics.

[5]  M. Gaudeul,et al.  Low selfing in a mass-flowering, endangered perennial, Eryngium alpinum L. (Apiaceae). , 2003, American journal of botany.

[6]  M. Quesada,et al.  Effects of Forest Fragmentation and Flowering Phenology on the Reproductive Success and Mating Patterns of the Tropical Dry Forest Tree Pachira quinata , 2003 .

[7]  S. McInnis,et al.  The Diversity of Self-Incompatibility Systems in Flowering Plants , 2003 .

[8]  L. M. Pound,et al.  Self-incompatibility in Eucalyptus globulus ssp. globulus (Myrtaceae) , 2002 .

[9]  B. Potts,et al.  Early ovule development following self- and cross-pollinations in Eucalyptus globulus Labill. ssp. globulus. , 2002, Annals of botany.

[10]  K. Ritland,et al.  Extensions of models for the estimation of mating systems using n independent loci , 2002, Heredity.

[11]  L. Galloway,et al.  The Contribution of Display Size and Dichogamy to Potential Geitonogamy in Campanula americana , 2002, International Journal of Plant Sciences.

[12]  I. Washitani,et al.  Genetic Diversity and Outcrossing Rate between Undisturbed and Selectively Logged Forests of Shorea curtisii (Dipterocarpaceae) Using Microsatellite DNA Analysis , 2002, International Journal of Plant Sciences.

[13]  E. Williams,et al.  Variation in Outcrossing Rates and Growth in Eucalyptus camaldulensis from the Petford Region, Queensland; Evidence of Outbreeding Depression , 2002 .

[14]  D. Ayre,et al.  A Molecular Genetic Assessment of Mating‐System Variation in a Naturally Bird‐Pollinated Shrub: Contributions from Birds and Introduced Honeybees , 2001 .

[15]  D. K. Hews,et al.  Pollination, breeding system, and genetic structure in two sympatric Delphinium (Ranunculaceae) species. , 2001, American journal of botany.

[16]  M. Moreno,et al.  Variation in outcrossing levels in faba bean cultivars: role of ecological factors , 2001, The Journal of Agricultural Science.

[17]  R. Vaillancourt,et al.  Eucalypt seed collectors: beware of sampling seedlots from low in the canopy! , 2001 .

[18]  S. Lee,et al.  Mating system parameters of Dryobalanops aromatica Gaertn. f. (Dipterocarpaceae) in three different forest types and a seed orchard , 2000, Heredity.

[19]  Melissa A. Millar,et al.  Mating system studies in jarrah, Eucalyptus marginata (Myrtaceae) , 2000 .

[20]  C. Eckert.  CONTRIBUTIONS OF AUTOGAMY AND GEITONOGAMY TO SELF-FERTILIZATION IN A MASS-FLOWERING, CLONAL PLANT , 2000 .

[21]  M. Moncur,et al.  Production of genetically improved Eucalyptus nitens seed for reforestation , 2000 .

[22]  K. Bawa,et al.  The effect of ecological factors on the mating system of a South American shrub species (Helicteres brevispira) , 2000, Heredity.

[23]  C. Ivey,et al.  Family outcrossing rates and neighborhood floral density in natural populations of swamp milkweed (Asclepias incarnata): potential statistical artifacts , 1999, Theoretical and Applied Genetics.

[24]  B. Potts,et al.  Floral visitors of Eucalyptus globulus subsp. globulus in eastern Tasmania , 1998 .

[25]  D. Grattapaglia,et al.  Estimation of outcrossing rate in a breeding population of Eucalyptus urophylla with dominant RAPD and AFLP markers , 1997, Theoretical and Applied Genetics.

[26]  W. Tibbits,et al.  Distribution, biology, genetics, and improvement programs for Eucalyptus globulus and E. nitens around the world. , 1997 .

[27]  B. Potts,et al.  Eucalypt genetics and genecology , 1997 .

[28]  R. Vaillancourt,et al.  Stand Density Influences Outcrossing Rate and Growth of Open-Pollinated Families of Eucalyptus globulus , 1996 .

[29]  L. Harder,et al.  Mating cost of large floral displays in hermaphrodite plants , 1995, Nature.

[30]  B. Potts,et al.  Inbreeding depression and changes in variation after selfing in Eucalyptus globulus ssp. globulus. , 1995 .

[31]  J. Davidson,et al.  Eucalypt Domestication and Breeding , 1994 .

[32]  J. Letouzey,et al.  Estimation of Fagus sylvatica L mating system parameters in natural populations , 1994 .

[33]  K. Ritland,et al.  Evidence for the partial dominance of viability genes contributing to inbreeding depression in Mimulus guttatus. , 1994, Genetics.

[34]  M. Morgan,et al.  Outcrossing rates and correlated mating within a population of Eichhornia paniculata (Pontederiaceae) , 1990, Heredity.

[35]  J. Wendel,et al.  Visualization and Interpretation of Plant Isozymes , 1989 .

[36]  G. Moran,et al.  Reduction in levels of inbreeding in a seed orchard of Eucalyptus regnans F. Muell. compared with natural populations. , 1989 .

[37]  B. Potts,et al.  Self-incompatibility in Eucalyptus , 1988 .

[38]  M. Clegg,et al.  Estimation of mating system parameters when outcrossing events are correlated. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[39]  S. Hopper,et al.  Genetic diversity and the insular population structure of the rare granite rock species, Eucalyptus caesia Benth , 1983 .

[40]  A. Stephenson.  WHEN DOES OUTCROSSING OCCUR IN A MASS‐FLOWERING PLANT? , 1982, Evolution; international journal of organic evolution.

[41]  James H. Torrie,et al.  Principles and procedures of statistics: a biometrical approach (2nd ed) , 1980 .

[42]  D. P. Fowler.  Effects of inbreeding in Red Pine, Pinus resinosa Ait. IV. Comparison with other northeastern Pine species. , 1965 .