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Breeding perennial tree crops often requires prediction of mature performance from juvenile data. To assess the utility of juvenile screens to predict salinity tolerance of mature pistachio trees, we compared performance of 3-month ungrafted seedlings and 4-year-old grafted rootstocks under salinity stress. The QTL allele associated with higher salt exclusion from seedling leaves conferred lower growth in saline field conditions, suggesting that mapping QTL in seedlings may be easier than discerning the optimal allele for field performance.

Persian walnut is a drought-sensitive species with considerable genetic variation in the photosynthesis and water use efficiency of its populations, which is largely unexplored. Here, we aimed to elucidate changes in the efficiency of photosynthesis and water content using a diverse panel of 60 walnut families which were submitted to a progressive drought for 24 days, followed by two weeks of re-watering. Severe water-withholding reduced leaf relative water content (RWC) by 20%, net photosynthetic rate (Pn) by 50%, stomatal conductance (gs) by 60%, intercellular CO2 concentration (Ci) by 30%, and transpiration rate (Tr) by 50%, but improved water use efficiency (WUE) by 25%. Severe water-withholding also inhibited photosystem II functionality as indicated by reduced quantum yield of intersystem electron transport (φEo) and transfer of electrons per reaction center (ET0/RC), also enhanced accumulation of QA (VJ) resulted in the reduction of the photosynthetic performance (PIABS) and maximal quantum yield of PSII (FV/FM); while elevated quantum yield of energy dissipation (φDo), energy fluxes for absorption (ABS/RC) and dissipated energy flux (DI0/RC) in walnut families. Cluster analysis classified families into three main groups (tolerant, moderately tolerant, and sensitive), with the tolerant group from dry climates exhibiting lesser alterations in assessed parameters than the other groups. Multivariate analysis of phenotypic data demonstrated that RWC and biophysical parameters related to the chlorophyll fluorescence such as FV/FM, φEo, φDo, PIABS, ABS/RC, ET0/RC, and DI0/RC represent fast, robust and non-destructive biomarkers for walnut performance under drought stress. Finally, phenotype-environment association analysis showed significant correlation of some photosynthetic traits with geoclimatic factors, suggesting a key role of climate and geography in the adaptation of walnut to its habitat conditions.

Uncovering the genetic basis of photosynthetic trait variation under drought stress is essential for breeding climate-resilient walnut cultivars. To this end, we examined photosynthetic capacity in a diverse panel of 150 walnut families (1500 seedlings) from various agro-climatic zones in their habitats and grown in a common garden experiment. Photosynthetic traits were measured under well-watered (WW), water-stressed (WS) and recovery (WR) conditions. We performed genome-wide association studies (GWAS) using three genomic datasets: genotyping by sequencing data (∼43 K SNPs) on both mother trees (MGBS) and progeny (PGBS) and the Axiom™ Juglans regia 700 K SNP array data (∼295 K SNPs) on mother trees (MArray). We identified 578 unique genomic regions linked with at least one trait in a specific treatment, 874 predicted genes that fell within 20 kb of a significant or suggestive SNP in at least two of the three GWAS datasets (MArray, MGBS, and PGBS), and 67 genes that fell within 20 kb of a significant SNP in all three GWAS datasets. Functional annotation identified several candidate pathways and genes that play crucial roles in photosynthesis, amino acid and carbohydrate metabolism, and signal transduction. Further network analysis identified 15 hub genes under WW, WS and WR conditions including GAPB, PSAN, CRR1, NTRC, DGD1, CYP38, and PETC which are involved in the photosynthetic responses. These findings shed light on possible strategies for improving walnut productivity under drought stress.

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.

Yield quality and quantity in hydroponic greenhouses usually rely on optimum crop root health and effective nutrient mobility. This study evaluated the effects of applying arbuscular mycorrhizal fungi and biochar on different growth characteristics of commercial rose cultivars in a hydroponic cultivation system. In this experiment, Rosa hybrida cultivars were 'Angelina' and 'Dolce Vita'. Treatments included concentrations of 0, 1.5, 3 and 6 g L-1 biochar, and 0 and 7 g L-1 of arbuscular mycorrhizal fungi as organic biofertilizers for the growth of rose plants. Biofertilizer application at 3 g L-1 biochar and 7 g L-1 arbuscular mycorrhizal fungi optimally increased flowering shoot diameter, flower diameter, flowering shoot length, and leaf phosphorus content. The 'Dolce Vita' cultivar responded more favorably to higher concentrations of arbuscular mycorrhizal fungi and biochar than the 'Angelina' cultivar in the hydroponic culture medium. Stem diameter, stem length, and flower diameter in both cultivars improved in response to higher biochar concentrations. The increased flowering shoot length resulted from root colonization by arbuscular mycorrhizal fungi and an enhanced nutrient uptake, especially phosphorus. A higher nutrient supply increased cell division and shoot growth. [ABSTRACT FROM AUTHOR]

Background: Accreditation and ISO 9001 programs in hospitals are widely adopted for quality control and quality improvement in healthcare. Objectives: The objective of this study is to identify stakeholders' perspectives and experiences regarding the implementation of accreditation and ISO 9001 programs in hospitals affiliated with the Social Security Organization in Alborz Province, Iran. Methods: In this qualitative study, participants were selected based on purposive sampling. For data collection, semi-structured one-to-one interviews were conducted with hospital staff in different positions (n = 30). All interviews were digitally recorded, transcribed verbatim, and analyzed using thematic analysis. Results: Based on the analysis, 10 primary themes and 88 subthemes were identified. The 10 primary themes were categorized as experiences, strengths, weaknesses, effective factors, and recommendations for the implementation of accreditation and ISO 9001 programs in hospitals. Proper planning, benchmarking, physician involvement, increased resources, and more training are suggested for the successful implementation of accreditation in hospitals. Additionally, fostering a positive culture, focusing on the executive dimension, changing managerial attitudes, training, and supporting and motivating staff are the most important recommendations for the implementation of the ISO 9001 program. Conclusions: The results provide important insights into the dimensions of implementing accreditation and ISO programs in hospitals, which can be used by health policymakers and managers to improve the implementation of these programs in Iranian hospitals. [ABSTRACT FROM AUTHOR]

Byline: Rajabali. Daroudi, Azin. Nahvijou, Mohammad. Arab, Ahmad. Faramarzi, Bita. Kalaghchi, Ali. Sari Background: Studies on economic burden demonstrate the impacts of some diseases and provide invaluable information for specifying [...]

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