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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]

This study was carried out to estimate the genetic diversity and relationships of 74 Iranian blackberry accessions assigned to 5 different species using inter-simple sequence repeats (ISSR) marker analysis and morphological trait characterization. Sixteen traits were analyzed, including phenological, vegetative and reproductive attributes (in 57 out of 74 accessions), and 10 ISSR primers were screened (in 74 accessions). The yield and leaf width had the highest and lowest genetic diversity, (diversity index = 62.57 and 13.74), respectively. Flowering and ripening date were recorded as traits with the strongest correlations (r = 0.98) . Ten ISSR primers were selected and produced a total of 161 amplified fragments (200 to 3500 bp), of which 113 were polymorphic. The highest, lowest and average PIC values were 0.53, 0.38 and 0.44, respectively. Principle component analysis (PCA) was based on morphological traits and showed that the first six components explained 84.9% of the variations among the traits. Meanwhile, the principal coordinate analysis (PCoA) was based on ISSR data and implied the first eight principal coordinates which explained 67.06% of the total variation. Cluster analysis was based on morphological traits and ISSR data ultimately classified all accessions into two and three major groups, respectively, so that the distribution pattern of genotypes was mainly based on species and the geographic origins. [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]

In some cases, polyploidy is an important phenomenon in the evolution of fruit crops. Polyploidy can be used in fruit breeding programs to develop varieties with higher yields and better fruit quality, as well as better adaptation to adverse environmental conditions. In this study, three wild species of blackberry were subjected to di􀀀erent degrees of induced polyploidy, and the e􀀀ects of which were evaluated on morphological, physiological, and phytohormonal traits. With the aimof gaining a deep insight into the generative phase of plant growth and development, di􀀀erent levels of induced polyploidy were evaluated on the three blackberry species, i.e., Rubus persicus Bioss. (2x, 4x, and 8x), R. caesius L. (2x and 4x), and R. hirtus Schreb. (2x and 4x). The results showed that the polyploid plants performed significantly better than their diploid counterparts in terms of morphological traits such as flower count per spike and berry weight, as well as biochemical traits such as total soluble solids in the leaves. Induced polyploidy increased berry weight and drupe count per fruit. Microscopic examinations revealed a smaller number of viable pollen in the polyploids, compared to the diploids. Electron microscopy showed that the octaploid R. persicus had larger conical cells on the flower surface, compared to the diploid R. persicus. Correlation analysis showed that the ratio of indoleacetic acid to jasmonic acid changed synergistically with the total soluble solids in the leaves during the fruit set. The ploidy level correlated significantly with the number of pistils, leaf green index, total soluble solids in the leaves, and glucose content in floral nectar. Overall, induced polyploidy allowed Rubus to develop advantageous traits that can benefit future breeding programs and expand reproductive research in blackberries. [ABSTRACT FROM AUTHOR]

It is proven that potassium (K) plays a key regulatory role in many physiological processes of plant growth and that K fertilization can improve the yield and quality attributes in fruit crops. This study was carried out to evaluate the effect of timing and various concentrations of foliar sprays of potassium sulfate, during fruit growth and maturation, on yield and quality of pomegranate fruit in Iran and Egypt, which have different pomegranate production systems. In Iran one, two or three sprays of 1% or 2% K-Leaf® (a high grade foliar potash booster) was used, and in Egypt a single spray of either 10 or 20 kg/ha, and two sprays of 10 and 20 kg/ha K-Leaf® were applied. Results showed that in both experiments in Iran and Egypt, foliar K treatments increased total and marketable yield of pomegranates, as well as fruit weight and size, flavor index (the ratio of total soluble solids/total acid). The treatments also improved the fruit's peel and aril color compared to the non-treated control plants. Results also demonstrated that multiple potassium sprays (two or three applications) were more effective than applying higher concentrations; as in many cases, there were no significant differences between 1 and 2% concentrations of K fertilizer in treatments with same number of applications (one, two or three sprays). Although three sprays of 2% K-Leaf® were the most effective treatments, it can be concluded that three sprays of 1% K-Leaf®) is probably more economically sound for use in pomegranate orchards. [ABSTRACT FROM AUTHOR]

Some cultivars of grapevine have very compact cluster which adversely affect its quality and marketability. 'Yaghouti' is a commercial early table grape cultivar that has very compact clusters. The present study was conducted to assess the effects of mechanical and chemical thinning as well as GA3 application on cluster morphology and berry size of grapevine cv. 'Yaghouti'. Treatments were chemical thinning agents including: NAA (7.5 and 15 mg/L), Ethephon (75 and 150 mg/L), Sevin (750 and 1500 mg/L) and mechanical thinning by a comb (comb thinning), applied a week after fruit set and unthinned clusters as control with 3 replications, 10 days after thinning, clusters were immersed in GA3 solution at 60 mg/L. Results indicated that berry numbers were reduced in all thinning treatments. Length, width and weight of berries increased significantly when treated with hand or chemical thinning. GA3 alone and Sevin at 750 mg/L in combination with GA3 treatment improved yield and the quality of berries. Total phenolics compounds, TSS and berries colour were improved in all thinning treatments. In general, application of Sevin at 750 mg/L combined with GA3 and hand thinning along with GA3 are proposed to improve quality of grapevine berries. [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]

By applying multivariate statistical analysis, this research aimed to estimate the heritability and find relationships between the vegetative and reproductive characteristics of Prunus scoparia and Prunus elaeagnifolia. Twenty genotypes of each species were selected randomly from cultivated populations and twenty-two traits including the tree, leaf, flower, nut and kernel attributes were measured. Results showed that there were high levels of genotypic and phenotypic variations among the genotypes of both species. Many of the measurements pertaining to the leaf, flower, nut and kernel, showed very high heritability (H² >90%) in both species, whilst some traits such as shoot diameter in P. scoparia and kernel moisture in both species had very lower heritability (H² <50%). Generally, the heritability of measured traits in P. elaeagnifolia were higher than those of P. scoparia, especially for economically important traits including yield (H² = 94 and H² = 54.61, respectively in P. elaeagnifolia and P. scoparia), nut weight (H² = 97.83 and H² = 85.39.61, respectively in P. elaeagnifolia and P. scoparia) and oil percentage (H² = 75.55 and H² = 61.43, respectively in P. elaeagnifolia and P. scoparia). Stepwise regression analysis revealed that the most influential factors on yield of P. scoparia, were the fruit set, flower diameter and leaf length, whilst for the P. elaeagnifolia, the yield was mostly determined by fruit set and leaf area. The high genetic diversity and heritability of the studied traits, indicates high genetic potential of this germplasm to be utilized in future breeding programs. [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]

BACKGROUND: Nutrient solution composition affects plant growth, yield and fruit quality. Nitrate, ammonium and urea are absorbable forms of nitrogen for plants however each form can have different effects on plant growth aspects. Urea is a low cost source of nitrogen and urease enzyme is activated by nickel (Ni), so using these nutrients may be beneficial for strawberry plant growth. The influence of different nutrient solution on strawberry cv. "Paros" growth, enzymatic activity and leaf mineral content was studied in this research at Shiraz University, Shiraz, Iran. OBJECTIVES: This study aimed to understand the role of Ni and different forms of nitrogen in the hydroponic culture on growth, nutrient composition and enzyme activity of strawberry plants, to identify whether a combination of different nitrogen form, especially urea and Ni, would improve plant growth and quality. METHODS: The effects of nitrate: ammonium: urea ratios (75:25:0, 50:25:25, 25:25:50, 25:0:75 and 0:0:100) and nickel sulfate concentration (0, 1 and 2 mg/L) in nutrient solutions were evaluated on strawberry cv. 'Paros' growth, mineral nutrient, and enzymatic activity. The trial was laid out as a factorial experiment with a completely randomized design. Rooted strawberry daughter plants were potted in 3 liter pots filled with cocopeat: perlite (1:1). Application of treatments started after establishment of the plants and continued for 5 months. RESULTS: Urea (25% and 50%) and nickel (1 mg/L) adding in the nutrient solution improved plant shoot and root dry weights. However, greater urea concentrations in the nutrient solution decreased nitrogen, potassium and phosphorous contents in leaves, but increased iron concentration. Urea concentration in strawberry leaves decreased when nickel concentration in the nutrient solution increased. Nitrate content in leaves of urea-fed plant decreased when urea concentration in nutrient solution increased. Urease activity increased with adding urea to the solution; however nitrate reductase activity was low at a high level of urea in nutrient solution. CONCLUSION: In addition to nitrate, adding nickel and urea in the nutrient solution improved growth and the enzymatic activity of strawberry plants, however it appeared that a higher rate of nickel and using urea as the only source of nitrogen was less beneficial. Overall, the best result was obtained from nickel at 1 mg/L and N source ratio of nitrate (50): ammonium (25): urea (25). [ABSTRACT FROM AUTHOR]

Cluster management in table grapes is an essential cultural practice for production of high quality table grapes. This issue has not been studied in the Intermountain West region in the United States. Thus, the objective of this project was to study the effects of cluster removal, cluster shortening, and vine girdling on yield and quality attributes of ‘Alborz’ table grape during 2012–14 growing seasons. Vines that did not receive cluster removal and cluster cutting (NoClRemNoClCut) tended to have a higher yield but smaller berry weight than those with other cluster managements every year. Vines receiving cluster removal, cluster shortening, and a trunk girdling (ClRemShort&Gird) regime tended to have larger berries and cluster weight than those with other treatments. However, girdled vines were more susceptible to cold damage. Vines receiving cluster removal and cluster shortening had slightly larger berries, better appearance, and marketability than those without cluster removal and without cluster shortening. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the effect of pollen source on fruit, aril, and seed characteristics in pomegranate. The cultivar Malas Yazdi was pollinated with three pollen sources including: Rabab Neyriz (a commercial cultivar), Malas Pishva Varamin (selected superior local cultivar), and Poost Sefid Dezful (non-commercial cultivar). The results showed that the rate of fruit set from different pollen sources varied from 13% to 46%. Pollen source also had significant effects on other fruit properties, such as fruit weight, fruit shape, fruit length and diameter, fruit peel color, fruit peel thickness, and edible portion of the fruit. Aril characteristics including number of arils per fruit, aril length and diameter, aril weight, and aril color were also significantly affected by pollen source as well as seed physical properties, including seed weight, seed length and diameter, seed hardness, and seed toughness. However ‘Malas Pishva Varamin’ as a pollinizer showed the lowest rate of fruit set, but performed better in terms of fruit quality and seed characteristic than ‘Rabab Neyriz’ and ‘Poost Sefid Dezful’. This is the first observation of xenia effect in pomegranate breeding and could serve as a new area of research for pomegranate production. These findings suggest that selection of suitable pollinizer could be a new area of research for pomegranate production. [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]