ISHS Acta Horticulturae 494: II International Symposium on Chestnut
GENETIC STRUCTURE AND QUANTITATIVE TRAITS VARIATION IN F1 FULL-SIBS PROGENIES OF CASTANEA SATIVA MILL. |
| Authors: | F. Villani, M. Lauteri, A. Sansotta, M. Cherubini, M.C. Monteverdi, C. Mattioni, M. Casasoli, M. Küçük |
| Keywords: | genetic variability, isozymes, RAPDs, quantitative genetics, morphometrics, water use efficiency |
| Abstract:
Among quantitative genetic studies, an increasing interest on tree species has been observed due to their importance to allow a sustainable use of the land. Previous studies aimed to assess the genetic variability in European chestnut showed a high degree of genetic differentiation between two groups of Turkish populations. Such pattern of differentiation was also observed for some morphological and physiological (water use efficiency) data. The aims of this study were: (i) to verify the level of reproductive isolation between the two genetically differentiated chestnut forms; (ii) to compare quantitative traits between differentiated demes; (iii) to quantify the level of correlation between genetic, morphometric and physiological data. In order to accomplish these objectives, crossed pollination using gametes from western (BURSA, B) and eastern (HOPA, H) Turkish populations were performed. Five trees for each population, selected for their genetic patterns based on isozyme analysis, were used for the crosses. This allowed to obtain 351 F1 seeds. All seeds were measured for 12 morphometric traits. Half of each seed was sown and grown in a nursery obtaining 127 six months old seedlings. Height, basal shoot diameter, number of leaves and carbon isotope discrimination (to estimate water use efficiency), were measured. The remaining half of the seed was used for genetic characterisation, by means of isozyme and RAPD analysis. Results of the controlled crosses showed higher pollen efficiency of HOPA. Higher germination capacity was observed in the  Bx B and BxH crosses as compared to those involving HOPA as female parent.
Factor analysis, carried out on the quantitative traits examined, showed a differential distribution of the BxB progenies as compared to the BxH ones, with the BxB being more homogeneous than the BxH. Results of the isozyme analysis, carried out on the F1 seeds, showed genotypic patterns congruent with the expected segregation ratio, confirming therefore the correctness of the crosses.
A remarkable similarity between the distribution pattern of genetic data and those based on morphometric and physiological parameters was also observed.
On this basis, RAPD analysis was carried out in order to determine the inheritance of the RAPD loci as preliminary step to detect a possible correlation between these nuclear markers and the quantitative traits examined.
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