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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]

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]

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]

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]

The development of cultivars with broader climatic adaptation has recently become the objective of most fruit breeding programmers. Regarding the importance of genetic control of cold hardiness as an influential characteristic for pomegranate and lacking studies in this area, the genetic control of cold hardiness in pomegranate using a partial mating scheme was studied. Five parents, including 'Rabab Post Ghermez Neyriz', 'Malas Yazdi', 'Poost Sefid Dezful', 'Malas Pishva Varamin', and 'Poost Nazok Torosh Abarkuh' with different cold hardiness capability were screened following a cold hardiness test in the laboratory and an evaluation of cold injury after natural freezing events in the field. The five screened cultivars were crossed in half-diallel crossing scheme with a total of 10 crosses in the Spring of 2014. Cold hardiness of the parent cultivars and the F1 progenies were investigated using the electrolyte leakage (EL) method. Results showed that both general combining ability (GCA) and specific combining ability (SCA) were statistically significant. The hardiest parent ('Poost Nazok Torosh Abarkuh') showed the largest positive GCA effect (1560.59) for winter survival, suggesting that this parent is capable to produce tolerant offspring with high breeding values in crossing programs. The significant SCA in this study suggests that specific crosses should be targeted to produce highly capable offspring. Cross between 'Poost Nazok Torosh Abarkuh' and 'Malas Pishva Varamin' showed high value for SCA (1661.74), indicating capability for production of tolerant offspring to the cold condition. Furthermore, high broad-sense heritability (0.70) and moderate narrow-sense heritability (0.45) for cold hardiness indicate that a reasonable progress could be made in improvement of this trait through conventional breeding. [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]

Chilling and heat requirements can affect agroclimatic distribution, growing season, and the marketing period of pomegranate (Punica granatum L.) cultivars in commercial production. This study was carried out to determine the chilling and heat requirements of 20 Iranian pomegranate cultivars/accessions, and to also examine the correlation of these features with tree and fruit characteristics, as well as geographic and climatic parameters of the original environment the plant materials came from. One-year-old stem cuttings from mature trees were used for measurements of chilling and heat requirements. The results showed a range of variation in chilling requirement among cultivars from 233 to 633 hours and heat requirement from 4096 to 7928 growing degree hour (GDH). Based on chill hours accumulated, cultivars including Bihaste Ravar, Bihaste Sangan Khash, and Anar Siah were categorized as very low chill (233-266 hours), whereas cultivars Poost Nazok Torosh Abarkuh, Malas Yazdi, Jangali Poost Ghermez Roodbar, Rabab Poost Ghermez Neyriz, and Makhmal Malas Shahreza were grouped as low chill (600-633 hours). Variation in seed hardness from 15 to 78 N was also recorded. Chilling requirement showed a moderate correlation with stomatal density, seed hardness, and wind speed (r = 0.42, 0.44, andL0.39, respectively), whereas stomatal density showed correlations of r = L0.34 and L0.57 with altitude and wind speed, respectively. We suggest taking chilling and heat requirements into account when selecting individual's cultivars and/or accessions suitable for cultivation in different agroclimatic regions. [ABSTRACT FROM AUTHOR]