Early varieties with a short active vegetation period are not exposed to abiotic stress factors for instance drought, high temperature, etc., caused by global climate change, and biotic stress factors such as codling moth (Cydia pomonella) and apple scab (Venturia inequalis) that cause serious economic losses. Therefore, their places are extremely important regarding sustainable, economical and quality production. In this context, four early varieties of apple (‘Vista Bella’, ‘Summer Red’, ‘Williams Pride’ and ‘Jersey Mac’) grown in Eskisehir—Turkey where has continental climate were characterized in terms of horticultural characteristics. The difference observed in flowering and harvest times between years showed that average air temperatures are essential on phenological characteristics. Furthermore, high temperature accelerates development physiology of fruit. Major important characteristics, namely, fruit length, width, weight, soluble solid content, antioxidant activity, vitamin C and total phenolic content were found in the range of 39.19–50.88 mm, 51.48–60.81 mm, 80.59–86.16 g, 11.87–12.19%, 50.69–80.57%, 2.24–4.79 mg 100 mL⁻¹ and 259.23–871.42 mg GAE (gallic acid equivalent) L⁻¹, respectively. ‘Summer Red’ and ‘Williams Pride’ varieties were found to be good in terms of pomological characteristics, while ‘Vista Bella’ came to the fore with its chemical properties. On the other hand, ‘Jersey Mac’ has shown superior performance in terms of both pomological and chemical characteristics. Pomological characteristics are affected more by ecological differences, while chemical characteristics vary according to the changes in the pomological properties. Pomological characteristics were found to have a significant positive correlation with each other but negatively correlated with chemical characteristics.

2018 ve 2019 yıllarında yürütülen bu çalışmada, yazlık grupta yer alan ‘Vista Bella’ çeşidine yine yazlık grupta yer alan ‘Summer Red’, ‘Williams Pride’ ve ‘Jersey Mac’ çeşitlerinin tozlayıcı olarak kullanılabilme potansiyelleri tespit edilmiştir. Sonuçlar doğrultusunda, ‘Vista Bella’ çeşidinin kendilenmesi neticesinde, meyve tutumunun %10,68 düzeyinde kaldığı ve kısmen kendine uyuşmaz olduğu görülmüştür. Çeşitlerin, çiçek tozu canlılığı ve çimlenme oranları sırası ile %74,33 - %67,00 ve %44,33 - 45,67 aralıklarında bulunurken, tam çiçeklenme tarihlerinin örtüştüğü görülmüştür. Ayrıca, yüksek meyve tutum oranı (%26,12 - 33,62) neticesinde, çeşitler arasında, gametofitik olarak uyuşmazlık olmadığı kanaatine varılmıştır. Ancak, elde edilen meyvelerde, çekirdek sayılarının kritik düzeyde olması sebebi ile minimum iki farklı çeşidin tozlayıcı olarak kullanılması gerektiği ortaya çıkmış olup, ‘Summer Red’ ve ‘Jersey Mac’ çeşitlerinin, ‘Vista Bella’ çeşidine tozlayıcı olarak kullanılması durumunda, fitokimyasal özellikleri nispeten iyileştirdiği tespit edilmiştir. Korelasyon analizleri sonucunda, meyve tutum miktarında meydana gelen artışın fitokimyasal birikimi azalttığı, buna karşın asitliğin artması ile birikimin teşvik edildiği bulunmuştur. Ayrıca antioksidan aktivitenin, toplam fenol (r= 0,57***) ve C vitamin (r= 0,31*) ile pozitif ilişki içerisinde olduğu tespit edilmiştir.

Pear (Pyrus communis L.) production worldwide exceeds 26 million tons, with over 70% of this production occurring in China. The most significant disease that seriously reduces pear yield is fire blight, caused by the bacterial pathogen Erwinia amylovora. In terms of disease resistance, it is known that biochemical characteristics such as phenolic compounds play an important role in addition to the genetic characteristics of the variety.This study aimed to compare the resistance levels of fire blight disease-resistant genotypes and susceptible cultivars using certain chemical analyses. According to the results, average the soluble solid content (SSC) ratio and pH value were found to be statistically significantly higher in resistant genotypes, while the total phenol value, catechin, and arbutin amounts were also found to be higher in resistant genotypes compared to susceptible cultivars. On the other hand, although titratable acidity (TA), total flavonoid and chlorogenic acid content were higher in susceptible varieties compared to resistant varieties, the results were not statistically significant. Among all cultivars and genotypes, genotype II-14-37 was found to have the highest values for total phenol, total flavonoid, chlorogenic acid, catechin, and arbutin content compared to the others. These results indicate that phenolic compounds play an important role in the resistance mechanism against fire blight in pears and that catechin and arbutin levels, in particular, can be used as potential biochemical indicators. Furthermore, SSC and pH values can also be added to these results as appropriate biochemical analyses.

In recent years, global climate change has increasingly disrupted optimal growing conditions for plants, leading to a decline in agricultural productivity. Rising air temperatures, in particular, induce heat stress in plants, resulting in significant economic losses. Consequently, the identification and utilization of ecologically well-adapted species and cultivars have become critically important. In this context, understanding the responses of different plant species and their cultivars to high-temperature stress is essential. This study was conducted on the experimental fields of Eskişehir Osmangazi University, Faculty of Agriculture, and aimed to evaluate the heat stress tolerance of various fruit species and cultivars. The plant material included plum cultivars (Angeleno, Black Beauty, Black Amber, Black Diamond, Formosa, Fortune, Friar), a sour cherry genotype and cherry cultivars (0900 Ziraat, Early Burlat, Kordia, Regina, Starksgold, Sweetheart, and Prunus mahaleb), apple cultivars (Golden Delicious, Pink Lady, Jersey Mac, Williams Pride, Fuji, Granny Smith, Mondial Gala, Red Summer, Vista Bella), and pear cultivars (Santa Maria, Williams, Ankara, Kiefer, Magness, Moonglow, Kaiser Alexandre, Nashi, Conference, Akça Limon, Bursa, Ekşi, Taş). The results revealed significant differences in heat stress tolerance both among species and among cultivars within certain species. Among cherry cultivars, ‘Kordia’ exhibited superior tolerance to high temperatures, while among pear cultivars, ‘Akça’ was identified as the most heat-tolerant. In contrast, no significant differences were observed among the evaluated plum and apple cultivars. When species were ranked according to their overall heat stress tolerance, from most resistant to most sensitive, the order was determined as follows: sour cherry, sweet cherry, pear, plum, mahaleb, and apple.

Objective: In this research, evaluations of F1 fall pear hybrids, that obtained from different cross combinations, were made to contribute to our country’s agriculture and gene pool.Material and Methods: 11 hybrids investigated in this research were obtained from the cross combinations that ‘Magness’, ‘Kiefer’, ‘Williams’ and ‘Santa Maria’ cultivars were maternal and, ‘Güz’, ‘Santa Maria’ and ‘Kiefer’ cultivars were used as pollinator parents. Susceptibilities of those hybrids to fire blight disease, pomological and biochemical characteristics were determinated. Besides, sensory parameters were added to the data attained by the measurements, and promising hybrids were detected through the modified weighted ranking method.Results: Fruit width, fruit length, shape index, fruit weight, fruit firmness, soluble solid content, pH, titratable acidity, vitamin C and antioxidant activity characteristics were varied between 53.22 - 84.25 mm, 52.91 - 105.01 mm, 0.95 - 1.62, 86.51 - 317.70 g, 3.32 - 8.41 kg/cm2, %8.77 - 16.53, 3.52 - 4.73, %0.14 - 0.59, 0.53 - 3.17 mg.L-1 and %26.43 - %75.09, respectively. Eight hybrids were evaluated as promising fall cultivars through the modified weighted ranking method.Conclusions: Due to the lack of a definite solution against fire blight, the chemicals used are harmful to human health and organic cultivation is becoming more widespread, the pears with high fruit quality parameters and disease resistant hybrids will come to the fore in the near future, it is thought that the hybrids (2-12-43, 2-15-93, 2-12-47, 1-17-20, 3-36-87, 2-33-32, 2-15-33 and 1-16-130) transferred to the forward observation plot will contribute to pear cultivation by registering in the following period.