Title: Traditional Sweet Chestnut and Hybrid Varieties: Chemical Composition, Morphometric and Qualitative Nut Characteristics

Authors: Igor Poljak, Nada Vahčić, Antonio Vidaković, Katarina Tumpa, Ivan Žarković i Marilena Idžojtić

Original: Agronomy (Q1, IF 2,603)

Category of paper: Research Paper

Key words: traditional sweet chestnut varieties, hybrid varieties, morphometric characteristics, standardized descriptors, chemical composition

Abstract: The chemical composition, morphometric and qualitative nut characteristics were studied in four traditional sweet chestnut and hybrid varieties produced on private estates in the Lovran surroundings, on the eastern slopes of Mount Učka, under the specific conditions of the sub‐Mediterranean climate. Seven morphological characteristics were measured, and 12 nut and kernel qualitative characteristics were estimated using standardized descriptors. In addition, the samples were analyzed for proximate constituents (moisture, crude fat, crude protein, ash and total carbohydrates) and macro‐ and micro‐nutrients (K, Mg, Ca, Na, Mn, Fe, Zn and Cu). Significant differences between traditional sweet chestnut and hybrid varieties were found in almost all of the studied morphometric and chemical nut characteristics. In general, chestnuts of hybrid varieties were characterized by larger fruits with higher moisture, crude protein, potassium, magnesium, sodium, iron and copper contents than in traditional sweet chestnut varieties. On the other hand, nuts of traditional sweet chestnut varieties were richer in total carbohydrates and crude fat. In addition, the presence of raised stripes, a small hilar scar and transversally ellipsoid nut shape were found to be typical for the traditional sweet chestnut varieties. Overall, our results suggest that the traditional varieties of the sweet chestnut can be easily differentiated from the new modern hybrid varieties by both morphological and chemical characteristics of the nut, and because of these differences, these two groups of chestnut varieties can have different practical uses.

Source language: English

Scientific area: Forestry

Title: Temporal and spatial genetic population structure of Cryphonectria parasitica and its associated hypovirus across an invasive range of chestnut blight in Europe

Authors: Marin Ježić, Janine Melanie Schwarz, Simone Prospero, Kiril Sotirovski, Mihajlo Risteski, Mirna Ćurković-Perica, Lucija Nuskern, Ljiljana Krstin, Zorana Katanić, Ema Maleničić, Igor Poljak, Marilena Idžojtić i Daniel Rigling

Original: Phytopathology

Category of paper: Research Paper

Key words: biological control, phytopathogenic fungus, population genetics, RNA virus

Abstract: Chestnut blight has spread throughout Europe since the introduction of its causal agent Cryphonectria parasitica over 70 years ago. In our study, we have analysed diversity of vegetative compatibility (vc) and microsatellite genotypes of C. parasitica, as well as sequence diversity of Cryphonectria hypovirus 1 (CHV1) in six populations from Switzerland, Croatia and North Macedonia. Resampling of local populations that were already investigated more than a decade ago allowed us to analyse the spatial and temporal population structure across an invasive range of the pathogen in Europe. Regardless which genetic marker was used, the over 60 year-old Swiss and Croatian populations had a high population diversity, while younger North Macedonian populations were mostly clonal. These diversity differences between the investigated populations remained stable over time. A high diversity of CHV1 was observed in all three countries, with North Macedonian strains forming a separate cluster from strains obtained in other countries. No correlation between vc diversity and CHV1 prevalence was observed, suggesting a well-established and maintained natural hypovirulence in all countries, further corroborated by an observed increase in genetic diversity of Croatian C. parasitica populations over time, without collapse of CHV1 prevalence.

Source language: English

Scientific area: Forestry

Title: Vegetative propagation of sweet chestnut and marrons

Authors: Katarina Tumpa, Marilena Idžojtić, Mirna Ćurković-Perica, Marin Jeić, Davor Jurtić , Damir Drvodelić, Mario Šango, Milovan Žigante i Igor Poljak

Original: Šumarski list

Category of paper: professional paper

Key words: vegetative propagation, grafting, marrons, sweet chestnut, varieties

Abstract: Select varieties of sweet chestnut called marrons are cultivated for their large and exquisite fruits. Most of the countries with native sweet chestnut populations have their autochthonous varieties that were arduously created through selective breeding over many centuries. Marron cultivation has a long history in Croatia, mostly in the Lovran area and its surroundings. Although threatened by pests and diseases, as well as land abandonment, some growers still practice the traditional cultivation methods. This paper provides an overview of the most common vegetative propagation methods utilized for the sweet chestnut and marrons sapling production, as well as a shorter overview of cultivation methods, breeding, and the importance of marron plantations in Croatia. Identical fruit characteristics can be inherited by progenies only through faithful passing on of the parent’s genotype, thus marrons are propagated vegetatively. Grafting in tree nurseries is the most common method of vegetative propagation of marrons. Other vegetative methods discussed are propagation by layering, cuttings and tissue culture, occasionally used in the reproduction of sweet chestnut.

Source language: Croatian

Scientific area: Forestry

Title: Population Variability of Sweet Chestnut (Castanea sativa Mill.) in Croatia According to the Fruit Morphology

Event: Sixth Croatian Botanical Symposium

Organizers: Croatian Botanical Society

Authors: Igor Poljak, Ivan Perković, Damir Drvodelić, Ivana Zegnal, Katarina Tumpa, Antonio Vidaković i Marilena Idžojtić

Date: August 30-September 1, 2019

Location: Zagreb, Croatia

Title: Laboratory Germination Testing of the Sweet Chestnut (Castanea sativa Mill.) According to ISTA Rules

Authors: Damir Drvodelić, Igor Poljak, Ivan Perković, Mario Šango, Katarina Tumpa, Ivana Zegnal i Marilena Idžojtić

Original: Forestry Journal - scientific forestry-specialized publication of the Croatian Forestry Association (0373-1332) (2019)

Category of paper: professional paper

Key words: sweet chestnut, seedling morphology, normal seedling, abnormal seedling, germination, forest nursery

Abstract: The paper presents the results of laboratory germination testing and morphological characteristics of sweet chestnut (Castanea sativa Mill.) seedlings. The research samples were collected in the sub-Mediterranean region of Croatia, and the working sample for germination testing was 8×25 seeds. Prior to germination testing, the seeds were stored in a refrigerator for three months at 3°C. The percentage of laboratory germination was established according to the percentage of regular seedlings which germinated normally after 27 days of testing. The testing was carried out in a laboratory under the conditions prescribed by ISTA (International Seed Testing Association). A digital photo camera was used to take photos of all abnormal seedlings, which were then catalogued with their pictures and descriptions. The results of this research are very useful for nursery practice and can be applied in producing plants from seeds, rootstocks for grafting, and further raising of seedlings to be grown in plantations.

Source language: Croatian

Scientific area: Forestry