Selection of Elms Tolerant to Dutch Elm Disease in South-West Romania
Dănuț Chira,
Florian G. Borlea,
Florentina Chira,
Costel Ș. Mantale,
Mihnea I. C. Ciocîrlan,
Daniel O. Turcu,
Nicolae Cadar,
Vincenzo Trotta,
Ippolito Camele,
Carmine Marcone,
Ștefania M. Mang
Affiliations
Dănuț Chira
Station of Brașov, “Marin Drăcea” National Research and Development Institute in Forestry, 13 Cloşca Str., 500040 Braşov, Romania
Florian G. Borlea
Faculty of Agriculture, Banat’s University of Agricultural Sciences and Veterinary Medicine, “King Michael I of Romania” of Timișoara, 119 Calea Aradului, 300645 Timișoara, Romania
Florentina Chira
Station of Brașov, “Marin Drăcea” National Research and Development Institute in Forestry, 13 Cloşca Str., 500040 Braşov, Romania
Costel Ș. Mantale
Station of Brașov, “Marin Drăcea” National Research and Development Institute in Forestry, 13 Cloşca Str., 500040 Braşov, Romania
Mihnea I. C. Ciocîrlan
Station of Brașov, “Marin Drăcea” National Research and Development Institute in Forestry, 13 Cloşca Str., 500040 Braşov, Romania
Daniel O. Turcu
Station of Timișoara, “Marin Drăcea” National Research and Development Institute in Forestry, 8 Pădurea Verde Str., 300310 Timișoara, Romania
Nicolae Cadar
Station of Timișoara, “Marin Drăcea” National Research and Development Institute in Forestry, 8 Pădurea Verde Str., 300310 Timișoara, Romania
Vincenzo Trotta
School of Agricultural, Forestry, Food and Environmental Sciences (SAFE), Università degli Studi della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza, Italy
Ippolito Camele
School of Agricultural, Forestry, Food and Environmental Sciences (SAFE), Università degli Studi della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza, Italy
Carmine Marcone
Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Salerno, Italy
Ștefania M. Mang
School of Agricultural, Forestry, Food and Environmental Sciences (SAFE), Università degli Studi della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza, Italy
Ophiostoma novo-ulmi continues to be one of the most dangerous invasive fungi, destroying many autochthonous elm forests and cultures throughout the world. Searching for natural genotypes tolerant to Dutch elm disease (DED) is one of the main objectives of silviculturists all over the northern hemisphere in order to save the susceptible elms and to restore their ecosystem biodiversity. In this regard, the first trial was established between 1991 and 1994, in south-west Romania (Pădurea Verde, Timișoara), using three elm species (Ulmus minor, U. glabra, and U. laevis) with 38 provenances. A local strain of Ophiostoma novo-ulmi was used to artificially inoculate all elm variants and the DED evolution was observed. Furthermore, in 2018–2021 the trial was inventoried to understand the local genotype reaction to DED in the local environmental conditions after almost 30 years. The outcomes of the present study proved the continuous presence of the infections in the comparative culture and its proximity, but the identified pathogen had a new hybrid form (found for the first time in Romania) between O. novo-ulmi ssp. americana x O. novo-ulmi ssp. novo-ulmi. Wych elm (U. glabra) was extremely sensitive to DED: only 12 trees (out of 69 found in 2018) survived in 2021, and only one tree could be selected according to the adopted health criteria (resistance and vigour). The field elm (U. minor) was sensitive to the pathogen, but there were still individuals that showed good health status and growth. In contrast, the European white elm (U. laevis) proved constant tolerance to DED: only 15% had been found dead or presented severe symptoms of dieback. Overall, the results of this study report the diverse reactions of the Romanian regional elm genotypes to DED over the last three decades, providing promising perspectives for improving the presence of elms in the forest ecosystems of the Carpathian basin.
