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This book brings together the latest information on almond genomics and transcriptomics, with a particular focus on cutting-edge findings, tools, and strategies employed in genome sequencing and analysis with regard to the most important agronomic traits. Cultivated almond [(Prunus dulcis (Miller) D. A. Webb, syn. Prunus amygdalus Batsch., Amygdalus communis L., Amygdalus dulcis Mill.)] is a tree crop producing seeds of great economic interest, and adapted to hot and dry climates. Domesticated in Southeast Asia, its small diploid genome and phenotypic diversity make it an ideal model to complement genomics studies on peach, generally considered to be the reference Prunus species. Both represent consanguineous species that evolved in two distinct environments: warmer and more humid in the case of peach, and colder and xerophytic for almond. The advent of affordable whole-genome sequencing, in combination with existing Prunus functional genomics data, has now made it possible to leverage the novel diversity found in almond, providing an unmatched resource for the genetic improvement of this species

Environmentally-friendly management techniques such as arbuscular mycorrhizal fungi (AMF) strategies are urgently required to improve plant nutrition and overcome abiotic stress. In this study, we evaluated the influence of symbiotic AMF on four pistachio rootstocks subjected to drought (100 % as the control, and 80 %, 60 %, and 40 % of field capacity as the treatments) and salinity (0.91 as the control, and 7.57, 16.12, and 24.63 dS/m using NaCl as the treatments) stress for 60 days in two separate experiments. Under both drought and salinity stress conditions, the root and shoot dry weights of the pistachio rootstocks markedly increased in the AMF-inoculated plants (+M). The accumulation of minerals in the leaves and roots of (+M) plants was significantly higher than in the non-inoculated plants (-M). AMF improved the nutritional status (N, P, Mg2+, and Ca2+) of the genotypes under both stress conditions. Mycorrhizal association significantly decreased Na+ and Cl− concentrations in the leaves and roots of the pistachio rootstocks under salinity stress. In (+M) plants under drought stress, hydrogen peroxide (H2O2) and methylglyoxal (MG) concentrations in leaf and root tissues and malondialdehyde (MDA) in the roots, and under salinity stress, the H2O2 and MG concentrations in the leaves and MDA in both tissues were lower than those in the (-M) plants. The Sarakhs rootstock under salinity stress accumulated lower minerals (N, P, K+, and Ca2+) and more antioxidants than the other rootstocks, which could be due to its higher sensitivity to this stress. Both stresses reduced the chlorophyll concentration and increased the oxidant content and electrolyte leakage from the roots and leaves of the rootstocks. Sarakhs rootstock under drought stress and Badami-Riz–e-Zarand and UCB1 rootstocks under salinity stress behaved better in terms of mineral absorption. Thus, they were more tolerant of drought and salinity stress, respectively. Based on these findings, the association

Many studies have investigated the role of miRNAs on the yield of various plants, but so far, no report is available on the identification and role of miRNAs in fruit and seed development of almonds. In this study, preliminary analysis by high-throughput sequencing of short RNAs of kernels from the crosses between almond cultivars 'Sefid' × 'Mamaee' (with small and large kernels, respectively) and 'Sefid' × 'P. orientalis' (with small kernels) showed that the expressions of several miRNAs such as Pdu-miR395a-3p, Pdu-miR8123-5p, Pdu-miR482f, Pdu-miR6285, and Pdu-miR396a were significantly different. These miRNAs targeted genes encoding different proteins such as NYFB-3, SPX1, PGSIP3 (GUX2), GH3.9, and BEN1. The result of RT-qPCR revealed that the expression of these genes showed significant differences between the crosses and developmental stages of the seeds, suggesting that these genes might be involved in controlling kernel size because the presence of these miRNAs had a negative effect on their target genes. Pollen source can influence kernel size by affecting hormonal signaling and metabolic pathways through related miRNAs, a phenomenon known as xenia.

Genus Prunus is of great importance for cultivation, mainly because its main species provide fruits and seeds, valuable ornamental qualifies and timber. However, stone fruit trees and almonds, major cultivars of genus Prunus, are sensitive to salt stress. Such sensitivity causes losses in stone fruit and almond production (ca. 50% of regular yield at high salinity grounds). Having in mind that symbiosis with arbuscular mycorrhiza fungi (AMF) may improve plant tolerance to salt stress and that symbiosis effect should be tested in case-by-case approach, we tested salt stress response of AMF inoculated GF677 rootstock (Prunus dulcis x Prunus persica hybrid) in this study. Adding to that, we tested GF677 symbiosis with two AMF species R. intraradices and F. mosseae. Results showed that under salinity stress AMF inoculated GF677 plants displayed improved physiological parameters (chlorophyll, soluble sugars and proline content) and increased antioxidant enzymes activity in comparison to non-inoculated control plants. Comparison of two AMF species beneficial effects on tested parameters revealed that for total chlorophyll content inoculation with F. mosseae has prevailed, while for total soluble sugars and proline content R. intraradices has prevailed. Finally, GF677 in symbiosis with F. mosseae was selected for molecular studies of salinity response. Since many of plants' genes involved in simultaneous response to salt stress and AMF colonization remained unidentified so far, we performed bioinformatics analysis of freely online available data to find differentially expressed genes common to these two responses. Upon GO classification and networking analysis of genes identified as common to both responses, we selected two most prominent ones (UDPGT73C6 and CYP707A3) and tested their expression profile in leaves and roots of F. mosseae inoculated GF677 rootstocks under salt stress. Even though specific roles of UDPGT73C6 and CYP707A3 are un-characterized in Prunus tree sp

Crown imperial (CI) has been used in traditional medicine. Today it is known that such beneficial effects are due to its richness in steroidal alkaloids (SA). Using de novo transcriptomics, orthologues/paralogues finder, phylogenetic analysis and tissue- and developmental stage-specific expression analysis, we identified ten genes and several TFs involved in the biosynthesis of SA in CI. The comparative analysis of ten genes expression profiles revealed the possibility of their co-regulation, which may imply the possibility of their organization in metabolic gene clusters. Having in mind convergent evolution of steroidal biosynthetic pathways in flowering plants and records of convergent evolution of specific proteins, observed expression patterns open a reasonable interest to investigate the possibility of the existence of genes cluster organization in SA pathway in the family Liliaceae or at least in some species of genus Fritillaria. Obtained results support transcriptomics as useful approach in elucidating genes underlying complex biochemical pathways.

In order to investigate the responses of Prunus rootstocks to drought stress, an experiment was carried out as factorial completely randomized design, and the effects of three watering regimes were assayed under greenhouse conditions. Cuttings of four propagated rootstocks (Cadaman, Myrobolan 29C, GF677 and GN15) were grown in five liter pots containing soil and sand mixture during four months and under regular irrigation. Then, drought stress treatment (100%, 75% and 50% Field Capacity) was applied for 40 days. The morphological parameters such as height, leaf number and crown diameter were measured during the stress period.

In many parts of the world, one of the most important restricting factors in cropproduction is salinity stress. Screening and selecting tolerant genotypes based on morphological characteristics is one of the primary actions toward achieving salt tolerant varieties. In the present study, 20 genotypes of alfalfa, mostly from Iran, were evaluated in two separate experimentsin Agriculture Research Center of Safi Abad, Dezful, SW Iran, in 2014-2015. However highly significant variations were observed among genotypes in the both experiments, the results obtained from the first experiment (carried out within growth chamber) were more or less different from those obtained from the second one (carried out in a heated greenhouse) regarding to categorizing the genotypes as sensitive or tolerant. The results obtained from the growth chamber study illustrated that Nikshahri was the most tolerant genotype and Harpinger and Diablo-verde were the most sensitive ones. While in greenhouse experiment, the genotype Yazdi showed the highest tolerance and Bami showed the highest sensitivity to salt under moderate salinity stress environment. A similar trend was also found under severe salt stress conditions. Correlation analysis indicated highly significant relationships among the tolerance indices. In addition, principle component analysis revealed that the dimensions of data could be reduced to two components with explaining approximately the 99 percent of total variations among the genotypes. &nbsp