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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]

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]

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]