Determination of Nutritional Value and Oxidative Stability of Fresh Walnut

Walnut (Juglans regia L.) is a tree with significant economic value and usage for human health and various food industries. However, fresh walnut kernels are a less widespread product than the dried kernels. This study aimed to determine the fresh walnut kernel properties including, fatty acid composition, proximate composition, total phenolics (TPs), total antioxidant capacity (TAC), acidic, peroxide and saponification values of extracted oil and minerals of fresh walnuts kernels. Green walnut fruits were harvested on commercial maturity. The content of different fatty acids (%) was determined as 16:0; 5.91, 18:1; 77.7, 18.2; 11.13 and 18:3; 2.84. Also, the essential nutritional compounds such as protein content (16 ± 0.67), ash (3± 0.32), water (20 ± 0.49), fat (40 ± 0.22) and total carbohydrate (21 ± 0.23) were quantified and reported in percentages. The energy content was 508 ± 0.48 kcal. Acidic values, peroxide values and saponification values in walnut oil were 3 ± 0.14, 0.3 ± 0.06 and 130 ± 0.54 respectively. Furthermore, the average mineral contents were also determined. In general, it can be claimed that fresh walnuts have significant amounts of protein, oil and minerals, and higher water content in comparison with dry nuts. Nonetheless, our results in comparison with the information available about dry walnuts showed that fresh walnuts contained less oil content compared to dried fruits

Phenological and Pomological Evaluation Reveals High Diversity among Walnut Populations in Southwestern Iran

High genetic diversity is the guarantee of success in a breeding program. Therefore, it is important to study the genetic diversity in plant populations. Because Iran consider as one of the primary walnut origin centers, this study was conducted to evaluate the genetic diversity of the walnut population in the Bavanat region in the Southwestern Iran during the 2010-2015 growing season. For this purpose, 349 walnut seed-originated walnut trees from seven different regions of Bavanat were pre-selected based on local information. After primary evaluation, 92 walnut genotypes were selected to be further studied. The phenological and pomological characteristics of the genotypes were evaluated based on IPGRI descriptor. The results showed that high genetic diversity was observed in the studied germplasm in terms of important horticultural traits, especially nut and kernel weight, kernel percentage, nut size, shell thickness, lateral bearing, leafing date, and harvest date. The nut weight, kernel percentage, kernel weight, and shell thickness varied between 6.75-16.33 g, 40.15-67.22%, 3.30-8.15 g, and 0.58-2.30 mm, respectively. Cluster analysis classified the studied genotypes into six main groups. Furthermore, correlations among some horticultural traits indicated that kernel weight, nut weight, difficulty of removal of kernel halves, and shell thickness are main traits in determining kernel percentage. Also, lateral bearing, leafing date, nut weight, and nut size determine the final yield of walnut trees. In conclusion, high biodiversity in the walnut population of Bavanat region provides unique plant genetic resources for walnut genetic improvement programs to achieve desirable commercial cultivars and rootstocks

Reliable propagation of Persian walnut varieties using SSR marker-based true-to-type validation

Simple sequence repeat (SSR) markers were used to authenticate ramets of 11 Persian walnut (Juglans regia L.) varieties. All varieties and 28 of their ramets (n = 39) were genotyped with 17 SSR markers. The genetic profiles revealed two off-types: the ramets Serr 4 (S4) and Vina 1 (V1). SSR fingerprints individuating 11 walnut varieties were possible using 13 polymorphic SSRs that could be used in the future to identify clones of these varieties. Except for ‘Chandler’, each cultivar could be distinguished using a combination of two SSR loci. This result emphasizes the efficacy of the SSR markers in true-to-type validation of walnut orchards

Advances in Rootstock Breeding of Nut Trees: Objectives and Strategies

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and their benefits to human health, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice used in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock–scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests.info:eu-repo/semantics/publishedVersio

Abiotic Stress - Plant Responses and Applications in Agriculture

""This book is not intended to cover all known abiotic stresses or every possible technique used to understand plant tolerance but, instead, to describe some of the widely used approaches to addressing such major abiotic stresses as drought, salinity, extreme temperature, cold, light, calcareous soils, excessive irradiation, ozone, ultraviolet radiation, and flooding, and to describe major or newly emerging techniques employed in understanding and improving plant tolerance. Among the strategies for plant stress survival, examples of both avoidance and tolerance are presented in detail and comprehensive case studies of progress and directions in several agricultural crops such as apple, walnut, grape and wheat are included."

In silico Coding Sequence Analysis of Walnut GAI and PIP2 Genes and Comparison with Different Plant Species

Introduction: Dwarfism is one of the important traits in breeding of crops and horticulture plants. A dwarfing rootstock will produce trees with 15-50% of standard trees size. In modern intensive fruit tree orchards, dwarfing rootstocks are commonly used to reduce trees size, enabling high-density planting and easy management, thus achieving higher yield. Trees on dwarfing rootstocks can also exhibit other economically important traits, such as precocious flowering, increased yield and increased disease resistance. Dwarf rootstocks have been extensively studied and released in stone and pome fruits, because of presence of genetic materials and the simplicity of budding methods. Control of tree size using genetically dwarf rootstocks for achievement to higher density and mechanized orchard systems is now very important for walnut production in the world especially in Iran. Many different genes can be involved in appear of this. Mutations in GAI and PIP2 genes cause dwarf trait by two different mechanisms in some plant species. In this case, we study in silico analysis of GAI and PIP2 genes consist of conserved sequences and domains, exon and intron number, function of their proteins, targeting, secondary and tertiary structure, and post translational modification. Materials and methods: The GAI and PIP2 mRNA and protein sequences (FASTA format) belonging to 17 monocotyledon and dicotyledon were downloaded from NCBI (http://www.ncbi.nlm.nih.gov) accessed, on September 2014. Several online web services and software were used for analysis of GAI and PIP2 mRNA and Proteins in plants. Comparative and bioinformatics analyses of PIP2 and GAI proteins were performed online at two websites NCBI (http://www.ncbi.nih.gov) and EXPASY (http://expasy.org/tools). Molecular Evolutionary Genetics Analysis (MEGA; version 4) program and CLUSTAL-W with default parameters were used for multiple alignments of sequences. The phylogenetic analysis of GAI and PIP2 protein was done with MEGA from aligned sequences. The motifs of protein sequences were found using the program of T-COFEE at website (http://www.ebi.ac.uk/Tools/msa/tcoffee/). The Neighbor-Joining (NJ) method was used to designing the phylogenetic tree. The predicted exons and introns in mRNA sequences were done by http://genes.mit.edu/GENSCAN.html website. The secondary structure of proteins was predicted by PSIORED online on http://bioinf.cs.ucl.ac.uk/psipred/. Prediction of 3D model of protein was performed using the 3D alignment of protein structure by BLASTp and PDB database as source. Also, targeting prediction of proteins was done online by TargetP at (http://www.cbs.dtu.dk/services/TargetP/) website. Results and discussion: In phylogenetic investigation among 17 different species, Walnut species evolutionary stand in dicotyledonous and woody plants by both of GAI and PIP2 genes and protein sequence clustering. By multiple alignments and investigation in conserved sequence of these genes in plant revealed that despite differences in cDNA length, there were very similarities in conserved region, secondary and tertiary structure. Protein analysis in the GAI gene family showed that the following domains including DELLA, TVHYNP, VHIID, RKVATYFGEALARR, AVNSVFELH, RVER, and SAW were conserved in this proteins. In secondary structure of protein, β-sheets and α-helixes specified by PSIPRED software for both of GAI and PIP2 proteins. GAI protein had 9 β-sheets and 15 α-helixes in its structure, also PIP2 protein had2 β-sheet (at 180-188 and 248-253) and 8 α-helixes. In comparison of 3D structure, walnut PIP2 protein was very similar to chain A of PIP2 protein of spinach (Spinacia oleracea) and GAI protein of walnut was similar to B-subunit of Arabidopsis GAI protein with 48% similarity. The length of GAI protein was varied from 636 aa in Malus baccata var. xiaojinensis to 336 aa in Physcomitrella patens among species. In walnut, the length of GAI and PIP2 protein was 613 aa and 287 aa, respectively. PIP2 protein length was similar in different species among 257 aa in Triticum aestivum to 290 aa in Zea mays. By exon-intron and targeting analysis of sequence, it was found that GAI gene target was in nuclear and had just one exon without intron, and PIP2 gene in walnut had 4 exons and 3 introns with cell membrane targeting. In results, Tcoffee analysis revealed that PIP2 gene was very conserved across the evolution between plant species in compared with GAI gene. Conclusion: Our results provide new insights into the evolutionary relationships of GAI and PIP2 proteins. The results of the sequence alignment showed that GAI and PIP2 in walnut and other species have high homology with each other. After this analysis, we can have a good perspective about molecular situation of walnut GAI and PIP2 genes. Result of this study can be used for make relationship between growth, flowering, and water uptake characteristics of these plants and their protein sequences. Also this research gives good information for us if we want to clone these genes from Iranian genotypes

Determining the Pollinizer for Pecan Cultivars

This study was conducted to determine the best pollinizer for five selected pecan cultivars in southwest of Iran at Safiabad Agricultural Research Center in 2014-2015. The cultivars included: 'GraTex', '10J', 'Wichita 6J', 'GraKing', 'Choctaw' as pollinated cultivars (♀) and 'GraTex', 'Peruque', 'Comanche 4M', '10J', 'Wichita 6J', 'Mohawk', 'Mahan', 'Stuart 2J', '3J', 'Stuart 4J', 'GraKing', 'Choctaw', 'Apache', '6M', 'Wichita 7J' and 'Comanche 5M.' as pollinizer cultivars (♂). In the first step, a pollination chart of cultivars was determined in two years. The pollination chart of cultivars showed that all the cultivars investigated during this study were dichogamous and also protogynous except for the 'Peruque'. ‘GraKing’ had the longest duration of shedding pollen. Pollination chart showed that 'Peruque', ‘GraKing’, and 'Stuart 2J' had flowering overlap with the selected cultivars. Pollen germination test showed that the germination ability was different among the cultivars. It was 45% for 'GraKing' and 35% for 'Peruque', which were both recommended as pollinizers in this study. '6M', 'GraTex' and 'Stuart 4J' cultivars had the highest pollen germination percentage of 65%, 60% and 60%, respectively. The results of controlled pollinationtest showed that different pollen sources had no significant effect on nuts per cluster but self-pollinated all of the cultivars significantly reduced fruit set in first and second years. Based on the present research, pollination in pecan orchard was necessary for adequate yield. Also, 'Peruque', 'GraKing' and 'Stuart 2J' were the best pollinizers for five selected cultivars in southwest of Iran

Advances in biotechnology and propagation of nut trees in Iran

As one of the main origin centers of nut trees, Iran is the fourth leading nut crops producer in the world (6% of total nut production). Due to the high genetic diversity, development of new varieties and rootstocks with desirable characteristics have been highly considered by fruit breeders in Iran. In this regard, molecular breeders concentrate on filling the gaps in the conventional breeding with the aim of accelerating breeding programs. Recent advancements in molecular breeding such as next-generation sequencing (NGS) techniques, high-throughput genotyping platforms and genomics-based approaches including genome wide association studies (GWAS), and genomic selection (GS) have opened up new avenues to enhance the efficiency of nut trees breeding. Over the past decades, Iranian nut crops breeders have successfully used advanced molecular and genomic tools such as molecular markers, genetic transformations and high-throughput genotyping to explore the genetic basis of the desired traits and eventually to develop new varieties and rootstocks. Due to a broad international cooperation, a clear perspective is envisaged for the nut breeding programs in Iran, especially based on new biotechnology techniques. The propagation of nut trees in Iran have also been dramatically improved. Different types of grafting and tissue culture (micropropagation or somatic embryogenesis) techniques for propagation of nut crops have been studied intensively in the last 30 years in Iran and the successful techniques have been commercialized. Several certified nurseries are producing grafted and micropropagation plants of walnut, pistachio and other nut crops commercially. A part of the grafted and micropropagaited plants of nut crops in Iran is being exported to the other countries. Establishing modern orchards of nut crops using new cultivars and rootsocks is presently being advised by professional consultants