Journal of Nuts
Volume:15 Issue: 1, Winter 2024

Persian oak (Quercus brantii) is a critical, economic, and environmental species of Zagros forests in Iran. The effects of climate change and drought have caused a decline in Persian oak populations, leading to a severe reduction in genetic resources for future conservation programs. This study aims to evaluate the diversity and population structure of Persian oak in the western forests of Iran using morphological features. A total of 187 samples were collected from 15 locations in the Ilam province. Twenty phenotypic traits related to leaf, seed, and trunk characteristics were evaluated. Several multivariate statistical analyses were performed. The results revealed significant morphological diversity among the Persian oak ecotypes. Correlation analyses revealed a significant positive correlation between leaf length attribute and distance from leaf base to maximum leaf width (0.55) and maximum width of the leaflet (0.64) traits. The leaf width at 50% attribute with the maximum width of the leaflet and distance from leaf base to maximum leaf width have a positive (0.8 and 0.51 respectively) and significant correlation (p≤0.05). According to principal component analysis, the components of leaf and seed traits have the most impact on morphological variance. Hierarchical cluster analysis divided the locations into two groups, with some oak locations distributed in two clusters, indicating higher diversity of this species in different locations. Further research is needed to determine the optimal ecotype; however, the oaks in Ghallaje region have characteristics that can increase their ability to resist water scarcity, making them potentially appropriate for reforestation in Ilam province.

Bionanocomposite active films made from tapioca starch and bovine gelatin, with the addition of roselle calyx extract (RCE) and zinc oxide nanorod (ZnO-N), were created as packaging material to protect walnuts against mold, yeast contamination, and lipid oxidation. Three types of packaging were produced: tapioca starch and bovine gelatin (control sample), tapioca starch, bovine gelatin, and RCE, and tapioca starch, bovine gelatin, ZnO-N, and RCE. Approximately 30 grams of walnuts were packed using each type of packaging and evaluated for acidity value, mold and yeast count, peroxide value, and sensory tests. After 90 days, the mold and yeast count of walnuts packed with RCE/ZnO-N and RCE was 4.49 and 4.65 log cfu/g respectively, compared to 4.95 log cfu/g in the control sample. At the end of the conservation period, the aroma score was 3.59 for walnuts packed with RCE/ZnO-N, compared to 2.5 for those packed with tapioca starch and bovine gelatin. The acidity value indicated that walnuts packed with RCE and RCE/ZnO-N had a positive effect on acidity, with the lowest value found in walnuts packed with RCE/ZnO-N. The study showed that bionanocomposite packaging films containing RCE and ZnO-N are effective in protecting walnuts against fungal contamination and oxidation.

In almonds (Prunus dulcis), selecting salt-tolerant rootstocks and genotypes is an appropriate breeding strategy. In the present research, we grafted two commercial almond cultivars (‘Sahand’ and ‘TS3’) on the ‘GF677’ rootstock. Then, we monitored the impact of salinity (0.5, 6.5, and 8.5 dS m-1) on the morphological, physiological, and molecular characteristics of the Sahand and TS3 cultivars. The photosynthetic rate, chlorophyll (a, b and total) content, and carotenoid content decreased with increasing salinity levels in both cultivars, with the least decrease observed in TS3. Under a salinity level of 8.5 dS/m, Sahand exhibited the lowest growth (8.9 cm), leaf area (5412.5 mm2), Chla, Chlb, Chltotal and carotenoid contents (0.58, 0.15, 0.74 and 0.31 mg g-1FW, respectively). Additionally, Sahand had a Fm/Fv (0.75), N content (1.33%) and Ca, B, Mg, S, Fe and Zn values of 1654.55, 1.64, 395.28, 168.6, 10.35 and 3.05 mg L-1, respectively. Furthermore, Sahand exhibited the highest MDA level (25.17 nmol g-1FW), TFC (2.95 mg GA g−1FW), Na content (649.84 mg L-1) and Cl content (3.52%).  the lowest TFC (1.75 mg GA g−1FW) and the highest NHX1 expression, photosynthesis rate (5.65 μmol m-2 s-1), gs (0.1 mol m-1 s-1) transpiration rate (6.08 mmol m-1 s-1), Ca, S and B content (1903.63, 196.9 and 2.09 mg L-1, respectively) were belonged to TS3 under 0.5 dS/m salinity. Higher levels of Mg and Fe in the TS3 cultivar resulted in the stablization of photosynthetic pigments. Compared to Sahand, TS3 had a higher nitrogen content, and its greater NHX1 expression was a molecular confirmation of its salt tolerance.

The pecan tree holds significant economic value due to its versatile cultivation and utilization. To expand its reach in global markets, pecan nut breeding aims to enhance both the quantity and quality of the product through meticulous planning. In this context, phosphorus and zinc are crucial nutrients for pecan nuts, playing a notable role in their nutritional profile. An experiment was conducted to investigate the effects of different levels of phosphorus and zinc on the nutrient content and yield of pecan trees. The experiment was designed in a factorial form with three levels of phosphorus (0, 250, and 500 kg P2O5 ha-1) and three levels of zinc (0, 25, and 50 kg Zn ha-1) in four replications. The results of the experiment showed that increasing the consumption of phosphorus had a significant effect on the concentration of phosphorus and iron in the leaves. However, a higher level of phosphorus application reduced the concentration of copper in the leaves. Similarly, the application of zinc increased the concentration of zinc (from 138.54 to 166.25 mg kg-1) in the leaves but decreased the concentration of phosphorus (from 0.15% to 0.13%). Interestingly, the application of 250 kg ha-1 of phosphorus led to a significant increase in the dry weight of the kernel, while higher levels of phosphorus had the opposite effect. These findings suggest that careful management of phosphorus and zinc levels in pecan orchards can have a significant impact on both nutrient content and yield. This research provides valuable insights for pecan breeders and growers seeking to optimize their practices and improve the quality of their crops.

There are numerous challenges associated with the large-scale production of walnut In vitro-plantlets. It is imperative to develop new environmental control systems for its In vitro propagation. Additionally, there is a lack of knowledge regarding the impacts of lighting systems on the morpho-physiological traits and biomass accumulation in walnut tissue-cultured explants. In this study, walnut nodal shoots were subjected to eight different light spectra, including white, blue, red, green, far-red, blue-red combination, red-far-red combination, and a fluorescent lamp serving as a control, over a period of 28 days. The results indicated that combined spectra treatments, such as blue-red and red-far-red, led to improved biomass accumulation (total fresh and dry weight) compared to other monochromatic light spectral treatments. Furthermore, Light-emitting diode (LED) treatments had a discernible impact on the morpho-physiological traits of walnut In vitro-explants. Specifically, white light spectra enhanced Specific leaf area (SLA), while the green light spectra increased leaf water content (LWC) when compared to other light treatments. Additionally, the application of far-red light elevated leaf mass area (LMA) and water content per unit leaf area (LWCA). The findings of this study demonstrate that the quality, morphological, and growth characteristics of In vitro explants of walnut can be enhanced by utilizing specific light spectra.

The influence of storing almond kernel genotypes derived from reciprocal crosses of ‘Mamaei’ and ‘Marcona’ cultivars (referred to as ‘G1’, ‘G2’, ‘G3’, ‘G4’, ‘G5’ and ‘G6’) on diverse quality parameters, encompassing moisture, ash, protein, oil, carbohydrates, fiber, and total vitamin E was investigated. The kernels were stored for 0, 6, and 12 months at room temperature. The results showed that the highest fresh kernel weight was observed in the ‘Marcona’ parent and two progenies, ‘G5’ and ‘G3’, at harvest time. The highest amounts of soluble carbohydrates were found in the ‘G4’ genotype, while the highest amounts of insoluble carbohydrates were observed in the ‘Mamaei’ parent and ‘G5’ genotype. The highest protein content was found in the ‘Mamaei’ parent and ‘G4’ genotype, while the maximum oil content was observed in the ‘G5’ genotype. The ‘G6’ genotype had the highest amount of total vitamin E. All studied traits showed a decreasing trend during the storage period, with the lowest amounts observed in all selected offspring after one year of storage. The results highlighted variations in traits such as fresh kernel weight, soluble and insoluble carbohydrates, protein, oil, and total vitamin E among different genotypes. Moreover, all traits exhibited a decline in values during storage, emphasizing the importance of selecting high-quality genotypes like ‘G5’ for almond breeding programs.

Natural plant products are suitable, eco-friendly, and toxicologically safe for using in integrated disease management approaches. Present work was carried out to decipher the potential of walnut kernels against Alternaria mali, the causal agent of leaf and fruit blotch on apples. Bioactive compound profiling of extracts was also done through HPLC and GC-MS to reveal the potential role of the compounds for disease management.  In the present study, a comparative analysis of the anti-fungal activity and concentration of active substances using HPLC and GC-MS in different walnut extracts has been carried out on the inhibition of A. mali.  The extracts of walnut kernels belonging to different eco-geographical regions viz. CS (Char-e-Sharief), KG (Kulgam), TM (Tangmarg), and KW (Kupwara) of Kashmir valley were prepared. The extracts prepared were added to potato dextrose agar (PDA) @ 1000, 2000, and 3000 ppm for evaluation against A. mali. The results revealed the efficacy of the different walnut extracts, with a maximum inhibition of mycelia growth in the range of 60%, 62.2%, and 71.1% at 3000ppm.  Among them, the TM (Tangmarg) extract showed the highest inhibition (71.1%).  The bioactive compounds were identified by using GC-MS chromatographic technique. The Quercetin content was quantified in the kernels of walnut, collected from four locations in Kashmir valley using HPLC. Among the selected genotypes, the highest Quercetin content was observed in samples collected from TM (Tangmarg) (0.765mg g-1) followed by KW (Kupwara) (0.705 mg g-1). The major phenolic components identified by GC/MS were methyl-7,8-Octadecadienoate, hexadecanoic acid, linoleic acid, epicatechin, and tocopherol. The results of the present study can be utilized further in the development of formulation from walnut kernels for evaluation under field conditions.