Morphological characteristics of chestnut Castanea sativa from the area of Una-Sana Canton
Una-Sana Canton (USC) has a large forest areas where chestnut Castanea sativa Mill. grows as a self-sprout tree. The aim of this paper was to determine the morphological characteristics of chestnut fruits from four self-sprout locations (Bužim, Bosanska Krupa, Cazin and Velika Kladusa), and plantation where the domestic tree is grafted with Italian Marroni. Number of fruits/kg, the useless fruit, the percentage of kernel, diameter, width, height and weight of fruits were determined. The number of fruit/kg ranged from 160-222.5, percentage of useless fruit varied between 0.88-6.7%. Percentage of kernel ranged from 78.5 to 87.3%. According to the diameter classification, width, height and weight of fruits, chestnuts fruit from USC enters the category of the smallest fruits of the Mediterranean area. Statistical significant differences (p≤0.01) in the number of fruits/kg and weight of fruits was found between locations, as well in the width of the fruit (p≤0.05), while there is no difference in the diameter and height of the fruit. For grafted chestnut, all the characteristics provided better quality.
Establishing an international sweet chestnut (Castanea sativa Mill.) provenance test: preliminary steps
Based on our experience gathered during the establishment of a regional provenance test for sweet chestnut (Castanea sativa Mill.) in southwest Germany, conceptional considerations are presented for designing a provenance trial which should cover the whole distribution range of this tree species. This preliminary proposal includes the specification of the objectives of the test and the selection of the provenances. Definite decisions on these will depend on the responses to questionnaires sent to COST G4 members and some other European research institutions working on sweet chestnut in order to evaluate ways of making sampling material from suitable occur- rences of sweet chestnut available and/or establishing experimental plots. Sweet chestnut (Castanea sativa Mill.) is a widespread tree species occurring primarily in the countries around the Mediterranean basin, including the Black Sea region and the western part of the Iberian Peninsula. At the northern margin of its distribution range north of the Alps, extensive occurrences are found mainly in wine-growing areas (e.g. in Germany particu larly along the Rhine and Moselle valleys). Sweet chestnut has long been cultivated and bred. Most probably agamic propagation in the form of grafting was the method used to establish sweet chestnut stands. It must be assumed that a vast loss in the genetic variability of the sweet chestnut gene pool has occurred over the centuries because, as a rule, just the phenotypes of highest quality and, consequently, only a few genotypes were propagated within each stand. Furthermore, as parasitic diseases spread, many stands were completely destroyed, especially those containing grafted trees (FINESCHI and MALTOVI 1991). Ac cordingly, the present populations in western Europe must be assumed to be the result of a mixture of native populations with the descendants of cultivated, grafted varieties. The species' existence per se is not endangered, but rather the integrity of the gene pool, so that measures for preserving the residual intraspecific genetic diversity are urgently required (FINESCHI and MALTOVI 1991). Besides its economic significance in nut production and supplying wood, nowadays the silvicultural and ecological properties of sweet chestnut have increasingly gained import - ance both in the fields of forestry and environmental protection (cf. Anonymus 1996, 1997, in print). Consequently, in order to obtain an insight into the current state of the extent of genetic diversity and the adaptation to differing environments (including both adaptability and adaptedness), more genetic studies based on gene markers (isozymes, DNA markers) as well as so-called provenance tests are urgently required for this tree species.
Geographic differentiation in adaptive traits of wild chestnut Spanish populations (Castanea Sativa Miller)
Se analizaron datos de brotacion, danos por heladas y crecimiento en altura de un ensayo de procedencias, con 19 poblaciones de gran parte del area de distribucion espanola de Castanea sativa, con la finalidad de estudiar la diferenciacion entre poblaciones. Se encontro una diferenciacion importante en fechas de brotacion y crecimiento. Los coeficientes de diferenciacion cuantitativa entre poblaciones fueron similares a los valores obtenidos en otras especies autoctonas. Las poblaciones espanolas de castano silvestre se clasificaron en tres grupos: poblaciones xericas mediterraneas de brotacion temprana, poblaciones de brotacion tardia de las montanas del Norte, poblaciones de caracter oceanico de brotacion intermedia de la costa gallega e islas Canarias. Las pautas de variacion geografica encontradas indican que la seleccion natural junto con un flujo genetico muy restringido fueron los factores determinantes de la estructura de las poblaciones. Se recomienda el uso de semillas de poblaciones locales en las plantaciones.