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Inheritance of freezing resistance in interspecific F1 hybrids of Eucalyptus
journal contribution
posted on 2023-05-17, 20:29 authored by Tibbits, WN, Bradley PottsBradley Potts, Savva, MHThe inheritance of freezing resistance in interspecific F1 hybrid families of Eucalyptus encompassing 27 different species combinations and a range of levels of hardiness was examined. Freezing resistance was assessed by determining the temperatures required to cause either 30% (T30), 40% (T40), or 50% (T50) leakage of electrolytes from excised leaf discs subjected to artificial freezing. Highly significant variation in freezing resistance occurred between species; the maximum difference between parents in any specific combination was over 9°C (E. gunnii x E. globulus). Freezing resistance was inherited in a predominantly additive manner in interspecific hybrids, although there was a tendency towards partial dominance toward the more sensitive species in some combinations (e.g., E. nitens x E. globulus, E. nitens x E. camaldulensis, E. gunnii x E. globulus). The full expression of this genetic variation appeared to increase with hardiness and in some cases appeared to vary with ontogeny. Estimates of individual narrow-sense heritability of freezing resistance for pure E. nitens families were h2 = 0.66_+0.44 and 0.46+_0.44. Across all species combinations examined, the heritability of F1 family means estimated from midparent regression was h2 = 0.76±0.06 and h2 = 0.89±0.06 for T40 and T50 values, respectively. The advantage of using selected parents for interspecific hybridization is demonstrated and the implications of these results for breeding for freezing resistance in Eucalyptus are discussed.
History
Publication title
Theoretical and Applied Genetics: International Journal of Breeding ResearchVolume
83Pagination
126-135ISSN
0040-5752Department/School
College Office - College of Sciences and EngineeringPublisher
Springer-VerlagPlace of publication
175 Fifth Ave, New York, USA, Ny, 10010Rights statement
Copyright 1991 SpringerRepository Status
- Restricted