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Key message: Basic comparative information was generated on phenotypic diversity of two important pear species (Pyrus glabra and P. syriaca) and superior genotypes were selected for conservation and utilization purposes. The first and most important step for the conservation and utilization of any wild germplasm is phenotypic characterization. By adopting a comparative approach and applying multivariate statistical analysis, this study aimed to estimate the extent of variations in vegetative and reproductive traits of Pyrus glabra and P. syriaca, located in the south of the Zagros region, Iran. For this purpose, 30 genotypes of each species were evaluated in their natural habitats. The results showed that both species have a high level of diversity in many traits, including leaf area, fruit weight, total soluble solids/titratable acids (TSS/TA) ratio, and total phenol content. P. glabra had more traits with high coefficients of variation than P. syriaca. In both species, correlation analysis showed that leaf length and width, leaf petiole length, and leaf area correlated positively with fruit traits such as fruit weight, fruit diameter, total soluble solids, and titratable acidity. Based on the Ward method, a cluster analysis classified the genotypes of each species into three main groups at distances of 10. Principal component analysis revealed that, in both species, the first three factors mainly comprised quantitative traits of fruits and leaves, explaining about 44% of the variance. The results of cluster analysis, bi-plot illustration, correlation analysis, and principle component analysis (PCA) were in general agreement in both species. The genotypes were classified into two main categories, reflecting known morphological differences within each species and their geographical proximity. While considering a trait-syndrome approach, some genotypes of P. syriaca, with large fruit size, high ascorbic acid content, antioxidant activity, total phenol content, and a balanced TSS/TA ratio, were selected as potential ideotypes and parent materials for drought resistance and fruit quality traits. The superior genotypes can contribute to the current goals of pear breeding programs. [ABSTRACT FROM AUTHOR]

The highest quality pomegranate necessitates a tropical or subtropical environment for proper growth and development. This study evaluated two pomegranate cultivars including Rabab Poost Ghermez Neyriz (RPGN) and Makhmal Malas Shahreza (MMS) for physical traits, biochemical properties, and juice quality in their native locations as well as other warm and arid regions during two growing seasons (2019–2020 and 2020–2021) in Iran. The results showed that cultivars with the maximum redness (a*) were more likely to originate in cooler climates, and the cultivar's responses to changing climates were also different. According to pomegranate characteristics, cultivars in different regions had different fruit, aril, and skin weights. According to these findings, pomegranate fruits cultivated in other climates than the origin climate have a smaller edible fraction. The findings also demonstrate that pomegranate fruits cultivated in mountain climates have more significant biochemical parameters such as total phenol, anthocyanin content, antioxidant capacity, and vitamin C than those produced in desert environment settings. The increased titratable acidity (TA), total soluble solids (TSS), and pH values of pomegranates produced in origin climate than the warm environment; thus, suggest that changes in pomegranate cultivar origin had a clear impact on fruit juice quality. Environmental factors, such as wind speed, altitude, and annual precipitation, had a significant correlation with a* skin, TSS, fruit weight, aril weight, edible portion, pH, TA, phenol, antioxidants, and anthocyanin content. [ABSTRACT FROM AUTHOR]

Salinity is an important abiotic stress which limits normal plant growth and productivity, particularly in arid and semi-arid areas. The foliar spray of acetic acid has recently been considered to enhance tolerance of abiotic stress, especially drought stress in plants but its effect on increased salinity tolerance in horticultural crops remains elusive. Hydroponically grown strawberry plants that were subjected to 40 mM sodium chloride for 90 days, were sprayed with 1- or 2-mM acetic acid (AA) three times including a week before, simultaneously and a week after application of salinity treatment. According to the results the electrolyte leakage, lipid peroxidation, and hydrogen peroxide, were increased by 45%, 46%, and 54%, respectively, under saline condition. While, the maximum quantum yield of PSII (Fv/Fm) decreased to 14% under salinity treatment. The maximum alleviation effect of salt stress was recorded in 1 mM foliar application of acetic acid, especially when applied 1 week before and simultaneous with salinity stress, resulting in significant decreases in electrolyte leakage to 13% and 15%, hydrogen peroxide to 30% and 32%, respectively, while the decline in lipid peroxidation was only observed in 1 week before salt stress to 39% compared to the control. The fruit yield reduced about 71% under 40 mM NaCl compared to the control, however, yield reduction was quite lower under 1- and 2-mM acetic acid treatments (31% and 45%, respectively). Acetic acid considerably increased antioxidant enzymes' activity including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) as well as the concentration of non-enzymatic antioxidants such as phenolic compounds under salinity stress conditions, especially when applied 1 mM AA a week before and simultaneously with salinity (25% and 24%, respectively). These results confirmed that acetic acid treatment especially with 1 mM concentration a week before and simultaneously with salinity treatment can be considered to improve the salt tolerance in strawberry under saline conditions. [ABSTRACT FROM AUTHOR]

Key message: The flowering time of wild almond species studied herein is more influenced by heat requirement, which partly justifies also the differences in flowering date during the different years in genotypes. Bloom frost tolerance, chilling and heat requirements can influence distribution and productivity of almond species. Both laboratory and field-related methods were employed to determine the chilling and heat requirements as well as bloom frost tolerance of several early-, mid- and late-flowering genotypes of two wild almond species (Prunus scoparia (Spach) C. K. Schneid and P. elaeagnifolia Spach). The variations of carbohydrates and soluble solids in the wood and buds were also measured during chilling period in laboratory method. Furthermore, the tolerance to spring-frost was evaluated using electrolyte leakage method. Results showed that in field method, the chilling requirement in P. scoparia ranged from 344 to 682 CU, whereas P. elaeagnifolia exhibited chilling requirements between 313 and 415 CU. The greatest chilling requirement was observed in the early-flowering genotype of P. scoparia. The heat requirement in P. scoparia ranged from 2737 to 9149 GDH, while this parameter varied from 4985 to 7788 GDH in P. elaeagnifolia. The highest heat requirement was observed in the late-flowering P. scoparia. The laboratory method failed to measure chilling and heat requirement of P. scoparia, due to sever bud abscission, but the chilling requirement of P. elaeagnifolia ranged from 383.33 to 450 h in this method, which was slightly higher than that of field method. Measurements of plants internal chemicals showed that prolonged duration of chilling is contributed to more extensive degradation of carbohydrates which results higher soluble solids' content. The highest tolerance to bloom frost was observed in the early-flowering P. elaeagnifolia (– 5.3 °C), while the lowest tolerance was recorded in the late-flowering P. scoparia (– 3.8 °C). There was a negative association between bloom's frost tolerance and soluble solids' content. [ABSTRACT FROM AUTHOR]

The fig (Ficus carica L.), is known as a precious fruit tree for its nutrition and medicinal values, economic importance and for sustainable production in the semi-arid and arid areas. Expanding the cultivation of fig in new vulnerable areas and the breeding programs in fig need a reliable high-efficient system for in vitro morphogenesis to meet future demands. This study was carried to develop an efficient protocol for indirect regeneration of F. carica L. cultivars 'Sabz' and 'Torsh' using thin cell layer (TCL) technique. The genetic fidelity of the regenerated plants was also evaluated using flow cytometry technique and ISSR markers. Stem segments of 10 mm in diameter were taken from mature plants, then explants were transversally cut into layers of 0.5–0.8 mm thickness. Callus induction was successful using Murashige and Tucker (MT) medium supplemented with 9.08 μM TDZ plus 9.8 μM IBA (IM3 medium) which resulted in 50 ± 6.11% calli in 'Sabz' cultivar. Morphogenic calli were cut into small pieces and cultured on Murashige and Skoog (MS) medium for shoot development. Maximum shoot regeneration (45%) was observed in 17.68 μM BAP in combination with 4.54 μM TDZ and 1.07 μM NAA (RM2 medium), with an average of 6.9 shoots per explant. Flow cytometry and ISSR molecular marker analyses confirmed the stability of ploidy level and genetic identity of indirectly regenerated plants in both cultivars. The results of this study demonstrate that indirect regeneration of F. carica L. by the use of TCL system is a reliable and promising approach for future mass propagation programs as well as possible in vitro breeding objectives. Key message: A rapid and high-efficient in vitro method for mass propagation via callus culture in two F. carica cultivars was established by using TCL technique for the first time. Flow cytometry and ISSR molecular markers confirmed the clonal identity of regenerants in both cultivars. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the shelf life of arils and the changes in their biochemical compounds in nineteen Iranian pomegranate cultivars during storage. Fruits were harvested when commercially mature and the arils were removed, packaged and stored at 5 ± 1 °C, at 85-90% relative humidity in a cold room. Samples of the stored arils were examined for biochemical features in temporal checkpoints throughout a storage period that lasted for 35 days. By using the onset of decay as an index, the shelf life of arils varied among cultivars, ranging from 7 days to approximately 21 days. Considering the quality attributes of ready-to-eat arils at the beginning of the experiment, substantial variations were observed among the cultivars with regard to their titratable acidity (0.50-8.47%), total soluble solids (13-18.66 °Brix), DPPH radical scavenging activity (63-87.44%), Gallic-acid-equivalent (2.64-6.95 mg/ml) and ascorbic acid (12.21-75.09 mg/l). In general, the decay of arils gradually increased during storage, but several cultivars—which exhibited a very slow process of decay—contained the highest content of titratable acidity, Gallic-acid-equivalent and total soluble solids (since the signs of decay appeared on around the twenty-first day of storage). In addition, titratable acidity increased slightly by the end of storage, whereas the ascorbic acid content, total soluble solids and Gallic-acid-equivalent were cultivar-dependent and did not show consistent patterns of change during storage. [ABSTRACT FROM AUTHOR]

Iran is very rich in plant genetic resources, due largely to the diversity in the agro-ecological landscape. Protection, preservation and utilization of genetic resources would facilitate development of premium varieties and biotech products that can potentially lead to a change in the food, agricultural, pharmaceutical and chemical industries in Iran. This paper discusses the distribution, ethnobotany, diversity and utilization of wild and domestic genetic resources of pome fruit species in Iran including apple ( Malus spp.), pear ( Pyrus spp.), quince ( Cydonia oblonga Mill.), hawthorn ( Crataegus spp.), medlar ( Mespilus germanica L.) and loquat ( Eriobotrya japonica Lindl.), all of which are members of the Rosaceae family. The goal of this paper is to highlight the importance of Iran as a contributor to the diversity of pome fruit genetic resources in the world. [ABSTRACT FROM AUTHOR]

Blackberries are a rich source of bio-chemicals such as anthocyanins and polyphenolic antioxidants. The evaluation of the extent of variation among wild genetic resources can provide useful information for the establishment of effective conservation strategies and future breeding programs. In this study, variations and inter-relationship of berry weight, total phenol (TP), total soluble solids (TSS), titratable acidity (TA), ascorbic acid (AA), anthocyanin and antioxidant activity were estimated in their values among 57 accessions belonging to 4 different Rubus spp. native to Iran. The experiments were performed during two consecutive years (2014 and 2015). Combine analysis showed that there is no significant difference between the data of 2 years in all measured traits. High or very high levels of variations were detected in berry weight (0.14–1.30 g), antioxidant activity (40.21–88.08%), anthocyanin (80.74–145.09 mg/100 g), TSS (7.9–17.8 °Brix), TA (0.36–0.83%) and AA (9.56–20.92 mg/100 g). This is while TP showed very low levels of variation (109.5–129.1 mg/100 g). Correlation analysis showed that antioxidant activity correlated highly and positively with all of the measured characteristics including ascorbic acid (r = 0.927), anthocyanin (r = 0.752), total phenol (r = 0.681), TSS (r = 0.473) and berry weight (r = 0.541) except for TA. Cluster analysis based on all measured characteristics showed a partial differentiation between the accessions based on their species and, to lesser extent, according to their origin within the main clusters. Based on the bi-plot of the first two PCAs, genotypes and traits classified into four quadrants. This grouping was in agreement with that of cluster analysis, considering the fact that almost all of accessions in quadrants II and III (with a few exceptions) were same to those in the first clade of cluster analysis and the genotypes grouped in quadrants I and IV, represents the accessions of clade 2 in cluster analysis. The projection of the traits vectors in PCA were also fully in accordance to that of correlation analysis in almost all of studied traits. Results showed that a rich source of variations is available considering berry weight, fruit bio-chemical and antioxidant activity in the Iranian wild Rubus species, which needs immediate conservation and worth to be utilized in commercial breeding programs. [ABSTRACT FROM AUTHOR]