The food needs for increasing population, climatic changes, urbanization and industrialization, along with the destruction of forests, are the main challenges of modern life. Therefore, it is very important to evaluate plant genetic resources in order to cope with these problems. Therefore, in this study, a set of ninety-one walnut (Juglans regia L.) accessions from Central Anatolia region, composed of seventy-four accessions and eight commercial cultivars from Turkey, and nine international reference cultivars, was analyzed using 45 SSR (Simple Sequence Repeats) markers to reveal the genetic diversity. SSR analysis identified 390 alleles for 91 accessions. The number of alleles per locus ranged from 3 to 19 alleles with a mean value of 9 alleles per locus. Genetic dissimilarity coefficients ranged from 0.03 to 0.68. The highest number of alleles was obtained from CUJRA212 locus (Na = 19). The values of polymorphism information content (PIC) ranged from 0.42 (JRHR222528) to 0.86 (CUJRA212) with a mean PIC value of 0.68. Genetic distances were estimated according to the UPGMA (Unweighted Pair Group Method with Arithmetic Average), Principal Coordinates (PCoA), and the Structure-based clustering. The UPGMA and Structure clustering of the accessions depicted five major clusters supporting the PCoA results. The dendrogram revealed the similarities and dissimilarities among the accessions by identifying five major clusters. Based on this study, SSR analyses indicate that Yozgat province has an important genetic diversity pool and rich genetic variance of walnuts.

Centuries-old generative reproduction, relatively favourable agro-ecological conditions, natural selection, and anthropogenic roles have significantly influenced the formation of a rich, heterogeneous population of common walnuts in Montenegro. This variability can be exploited by applying a positive selection of genotypes that would have good ecological adaptability and high economic value and that would not lag behind walnut varieties originating from other countries. The paper presents the results of studying 20 selected walnut genotypes from the continental part of Montenegro in a three-year period. Šeinovo variety and the Rasna selection were used as standard. The most important biological and pomological properties were investigated based on the international walnut descriptor. The basic criteria on which the selection approach was based were: late vegetation initiation, earlier date of end of vegetation, well kernel ratio, ease of kernel removal from the shell, shell texture that should be less rough, protecting the kernel, tasty kernel, light coloured kernel, and good chemical composition of the kernel. Genotypes had fruit weight between 8.43 and 13.84 g, kernel weight between 4.20 and 6.54 g, kernel ratio between 39.20 and 52.25%, oil content between 62.04 and 67.23%, and protein content between 13.91 and 19.04%. Most of the selected genotypes have the late time of leaf bud burst, and from that point of view, the BP44 and BP42 genotypes that the leafing on May 5 and 6 are especially interesting, due to avoidance of late frost. The walnut is adapted to the existing agro-ecological conditions over a long period of successful growth in this region, and most genotypes finish their vegetation earlier and are prepared to enter the period of winter dormancy. Genotypes BP09 and AN29 with their properties surpass the worldwide recognized Šeinovo, and in this region, highly valued selection Rasna. BP48 and BP50 genotypes also deserve attention due to the quality of the fruit.

CRISPR (short for “Clustered Regularly Interspaced Short Palindromic Repeats”) is a technology that research scientists use to selectively modify the DNA of living organisms. CRISPR was adapted for use in the laboratory from the naturally occurring genome-editing systems found in bacteria. In this work, we reviewed the methods used to introduce CRISPR/Cas-mediated genome editing into fruit species, as well as the impacts of the application of this technology to activate and knock out target genes in different fruit tree species, including on tree development, yield, fruit quality, and tolerance to biotic and abiotic stresses. The application of this gene-editing technology could allow the development of new generations of fruit crops with improved traits by targeting different genetic segments or even could facilitate the introduction of traits into elite cultivars without changing other traits. However, currently, the scarcity of efficient regeneration and transformation protocols in some species, the fact that many of those procedures are genotype-dependent, and the convenience of segregating the transgenic parts of the CRISPR system represent the main handicaps limiting the potential of genetic editing techniques for fruit trees. Finally, the latest news on the legislation and regulations about the use of plants modified using CRISPR/Cas systems has been also discussed.

Green husks are the outer layer of walnut fruits. They form part of the agro-residues discarded away upon nut maturity in the walnut industry. Although it is not used, research studies show that green husk is a rich source of natural bioactive phytochemicals. A total of 83 individual phenolic compounds were identified in walnut husks, mainly consisting of naphthoquinones, flavonols, and hydroxycinnamic acids. There is no standard profile of phenolic compounds in walnuts; the quantity and quality of phenolic compounds vary by cultivar. Walnut extracts exhibit strong antioxidant activities and play an important role in the plant’s defence mechanisms against diseases, attacking different plant organs. The study provides a review of total phenolic content and individual phenolic compounds identified in green husks of different walnut cultivars as documented in different studies. It also explores the role and application of green husks in various industries such as traditional medicine, textile, wood, leather, beverage, and agriculture. In addition, the effects of phenolic compounds on biotic and abiotic factors are also evaluated.

In September 2017 brown or black, huge circular sunken necrotic lesions were observed on walnut fruits (Juglans regia L.) in the fruit variety collection of NARIC Research Institute in Érd, Hungary. Similar symptoms were visible on walnut fruits in three other locations of the country in 2018, the disease symptoms occurred diffusely (in orchards of Lengyeltóti, Nagyoroszi) or widely (in orchards of Sarród, Érd). Early symptom stages were observed in June 2018 with small dry spots affecting the surface of the husk. Acervuli were formed on collected fruit samples and orange conidial masses appeared under wet conditions. Conidia were hyaline, unicellular and fusiform, pointed at one or both ends, and measured 11.0-17.6 x 3.8-5.0 µm (n = 100). The fungus was isolated from necrotic tissues and conidial masses on potato dextrose agar (PDA) medium amended with chloramphenicol (25 mg/l). The colonies were white to pink on the upper side and pink with black spots on the reverse. Acervuli formed and produced conidi...