scholarly journals Girdling Effects on Fruit Maturity, Kernel Quality, and Nutritional Value of Walnuts (Juglans regia L.) alongside the Effects on Leaf Physiological Characteristics

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 200
Author(s):  
Miltiadis V. Christopoulos ◽  
Mina Kafkaletou ◽  
Athanasia D. Karantzi ◽  
Eleni Tsantili

Girdling, based on the accumulation of photosynthetic products above the girdling zone, is a common technique applied to tree species to increase the yield and fruit quality. The aim of this study was to investigate the girdling effects on photosynthesis and soluble sugars (Sols) of leaves in fruiting shoots and, for the first time, on quality variables of ‘Franquette’ walnuts harvested at two harvests, early and late, 43 and 84 d after treatment, respectively. Girdling was conducted on a part of four-year old branches at the onset of kernel growth. At late harvest, coinciding with commercial harvest, girdling advanced the mature fruit percentage, kernel weight, and oil content, whereas decreased kernel moisture and slightly affected the color brightness, although kernels remained with an extra light color. Advanced maturation increased linoleic acid and polyunsaturated fatty acid (PUFA) fraction in oil, whereas it decreased palmitic acid and the saturated fatty acid (SFA) fraction in oil, kernel total antioxidants, and Sols (sucrose, glucose, fructose) in kernels and leaves and leaf photosynthesis (Pn), whereas girdling had no effect on these variables. Oil rancidity remained stable throughout the experiment. Development of callus was observed on tree wounds 84 d after treatment. Conclusively, girdling enhanced the fruit maturation, resulting in higher uniformity of maturity and increased oil yield with no quality deterioration or apparent tree damage.

2008 ◽  
Vol 133 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Ossama Kodad ◽  
Rafel Socias i Company

Nut and kernel dimensions and sphericity, shelling percentage, oil content, and fatty acid composition were studied over 2 years in 15 advanced almond (Prunus amygdalus Batsch) selections. The aim was to test the effect of pollination type on these fruit traits for this group of new self-compatible selections of a mostly self-incompatible species as well as the yearly effect on these variables. Variability between selections was much higher than that between years, showing a moderate level of year-stability and a significant year effect only for some variables. The different pollination treatments affected all chemical components studied, as well as nut and kernel weight, but not the other physical traits. Self-pollination decreased kernel weight and volume as well as oil content and percentage of linoleic acid but increased the percentage of oleic acid. These variations in the fatty acid composition were in the trend of increasing kernel quality. Inbreeding depression could also negatively affect several aspects of nut and kernel quality. Thus, autogamous almond genotypes without apparent symptoms of inbreeding depression may yield kernels of increased nutritional and industrial quality.


Weed Science ◽  
2021 ◽  
pp. 1-23
Author(s):  
Katherine M. Ghantous ◽  
Hilary A. Sandler

Abstract Applying control measures when carbohydrate levels are low can decrease the likelihood of plant survival, but little is known about the carbohydrate cycles of dewberry (Rubus spp.), a problematic weed group on cranberry farms. Weedy Rubus plants were collected from areas adjacent to production beds on commercial cranberry farms in Massachusetts, two locations per year for two years. For each site and year, four entire plants were collected at five phenological stages: budbreak, full leaf expansion, flowering, fruit maturity, and after onset of dormancy. Root sections were analyzed for total nonstructural carbohydrate (TNC; starch, sucrose, fructose, and glucose). Overall trends for all sites and years showed TNC were lowest at full leaf expansion or flowering; when sampled at dormancy, TNC concentrations were greater than or equal to those measured at budbreak. Starch, a carbohydrate form associated with long-term storage, had low levels at budbreak, leaf expansion and/or flowering with a significant increase at fruit maturity and the onset of dormancy, ending at levels higher than those found at budbreak. The concentration of soluble sugars, carbohydrate forms readily usable by plants, was highest at budbreak compared to the other four phenological samplings. Overall, our findings supported the hypothesis that TNC levels within the roots of weedy Rubus plants can be predicted based on different phenological growth stages in Massachusetts. However, recommendations for timing management practices cannot be based on TNC cycles alone; other factors such as temporal proximity to dormancy may also impact Rubus plants recovery and further research is warranted. Late-season damage should allow less time for plants to replenish carbohydrate reserves (prior to the onset of dormancy), thereby likely enhancing weed management tactics effectiveness over time. Future studies should consider tracking the relationship between environmental conditions, phenological stages, and carbohydrate trends.


2021 ◽  
Vol 12 ◽  
Author(s):  
Saqib Mahmood ◽  
Beenish Afzal ◽  
Shagufta Perveen ◽  
Abdul Wahid ◽  
Muhammad Azeem ◽  
...  

Water-scarce areas are continually increasing worldwide. This factor reduces the quantity and quality of crops produced in affected areas. Physical seed treatments are considered economical and ecofriendly solutions for such problems. It was hypothesized that a moderately drought-tolerant crop grown from seeds treated with a He-Ne laser utilizes water-limited conditions better than plants grown from untreated seeds. A field study was conducted, growing a moderately drought tolerant crop (sunflower) with supportive seed treatment (He-Ne laser treatment at 300 mJ) for 0, 1, 2, and 3 min. Thirty-day-old plants were subjected to two irrigation conditions: 100% (normal) and 50% (water stress). Harvesting was done at flowering (60-day-old plants) at full maturity. The sunflowers maintained growth and yield under water limitation with a reduced achene number. At 50%, irrigation, there was a reduction in chlorophyll a, a+b and a/b; catalase activity; soluble sugars; and anthocyanin, alongside elevated proline. The improved chlorophyll a, a+b and a/b; metabolisable energy; nutritional value; and yield in the plants grown from He-Ne-laser-treated seeds support our hypothesis. Seeds with 2-min exposure to a He-Ne laser performed best regarding leaf area; leaf number; leaf biomass; chlorophyll a, a+b and a/b; per cent oil yield; 50-achene weight; achene weight per plant; carotenoid content; and total soluble phenolic compound content. Thereafter, the leaves from the best performing level of treatment (2 min) were subjected to high-performance-liquid-chromatography-based phenolic profiling and gas-chromatography-based fatty acid profiling of the oil yield. The He-Ne laser treatment led to the accumulation of nutraceutical phenolic compounds and improved the unsaturated-to-saturated fatty acid ratio of the oil. In conclusion, 2-min He-Ne laser seed treatment could be the best strategy to improve the yield and nutritional value of sunflowers grown in water-limited areas.


2020 ◽  
Vol 21 (23) ◽  
pp. 9093
Author(s):  
Xinchi Zhao ◽  
Guiyan Yang ◽  
Xiaoqiang Liu ◽  
Zhongdong Yu ◽  
Shaobing Peng

Walnut (Juglans regia) is known as a promising woody oil crop with abundant polyunsaturated fatty acids in its kernel. However, the regulation mechanism of walnut oil accumulation and fatty acid metabolism is still poorly understood, which restricted the breeding and genetic improvement of high-quality oil-bearing walnuts. To reveal the molecular mechanism of walnut oil accumulation, considering the potential regulation of microRNA (miRNA) in seed development, in this study, the oil content of walnut kernel on the 80th, 100th and 120th day after flowering (DAF) was tested and the corresponding proportions are 11.51%, 40.40% and 53.20%. Between DAF of 80th~120th, the content of stearic acid and oleic acid tended to increase, but the proportion of other fatty acids tended to decrease. Meanwhile, comparative transcriptome and sRNA-seq analysis on three stages (80th, 100th and 120th DAF), found 204 conserved miRNAs and 554 novel miRNAs in walnut kernels, among which 104 key genes related to walnut oil accumulation were screened. The phospholipid:diacylglycerol acyltransferase metabolic pathway may contribute more to oil accumulation in walnut. 16 miRNA-mRNA regulatory modules related to walnut oil accumulation and fatty acid synthesis were constructed. 8 known miRNAs and 9 novel miRNAs regulate 28 genes involved in fatty acid (FA) metabolism and lipid synthesis. Among them, jre-miRn105, jre-miRn434, jre-miR477d and jre-miR156a.2 are key miRNAs that regulate walnut FA synthesis. Jre-miRn411 and jre-miR399a.1 are closely related to oil accumulation. These data provide new insights and lay the foundation for subsequent studies on walnut FA synthesis and oil accumulation.


2020 ◽  
Author(s):  
Bingmei Sun ◽  
Hua Yan ◽  
Chao Li ◽  
Linlin Yin ◽  
Fei Li ◽  
...  

Abstract Background: Gestational diabetes mellitus has a long-term effect on pregnant women. Walnut (Juglans regia L.) oil-derived polyunsaturated fatty acid (PUFA) possesses multifarious pharmacological activities. This study investigated the beneficial effects of walnut oil-derived PUFA on glucose metabolism, pregnancy outcomes, oxidative stress, and lipid metabolism in gestational diabetes mellitus.Methods: The GDM rat model was generated by intraperitoneal injection of streptozotocin (40 mg/kg) on gestational day (GD) 6, GD7 and GD8. The differences between groups were estimated using one-way ANOVA followed by the Tukey’s multiple comparison test for post-hoc analysis.Results: The results indicated that PUFA could mitigate GDM in pregnant diabetic rats, as embodied by the decrease of fasting blood glucose and the increase of plasma insulin and hepatic glycogen levels. Also, PUFA could suppress oxidative stress in pregnant diabetic rats, as reflected by the decrease of malondialdehyde (MDA) content, an increase of superoxide dismutase (SOD), catalase (CAT) and gutathione peroxidase (GSH-Px) activities. PUFA could also mitigate the abnormal changes of lipid profiles in plasma and hepatic tissue. Moreover, the relative mRNA expression of sterol regulatory element-binding transcription factor-1 (SREBP-1), stearoyl-CoA desaturase-1 (SCD-1), fatty acid synthase (FAS), and acetyl-coenzyme A carboxylase (ACC), was suppressed by PUFA in pregnant diabetic rats.Conclusions: These results suggested that PUFA supplementation during pregnancy is beneficial in preventing diabetic complications in pregnant rats.


2020 ◽  
Vol 73 (3) ◽  
Author(s):  
Zeki Nurhan Büyüksolak ◽  
Mehmet Atilla Aşkın ◽  
İbrahim Kahramanoğlu ◽  
Volkan Okatan

This research was conducted to investigate some quality parameters of nuts of walnut (<em>Juglans regia </em>L.) ‘Chandler’ grown at different altitudes. Studies were conducted in Eşme Town, Uşak Province, in three different villages situated at an average altitude of 650 m, 800 m, and 900 m. Studies were conducted in Karaahmetli, Takmak, and Yeşilkavak villages in the 2012–2013 production year and orchards with similar soil and topography characteristics were selected. Plant protection, plant production, and other cultivation practices in the sampled orchards were also noted and orchards with the same attributes were selected. During the harvesting period, regular measurements were taken to determine correct time for harvesting. Nuts were hand-harvested when the color of the membrane separating the kernel and outer parts turned brown. A total of 35–40 nuts were randomly selected and harvested from the three orchards and 15 of those were randomly selected for further analysis. Nut weight, internal (kernel) weight, shell thickness, kernel color, dry matter, moisture, ash, protein, oil, mineral matter, and free fatty acid composition were determined. Results showed that the site altitude significantly influences walnut’s quality and it is highly important to consider the site altitude as a factor before planting new orchards. Results showed that nut height, nut width, nut length, nut weight, kernel weight, shell thickness, oil content, phosphorus content, magnesium content, oleic acid, and linolenic acid increase with an increase in altitude. On the other hand, kernel ratio, total nitrogen, and protein content were found to decrease with increasing site altitude.


2019 ◽  
Vol 47 (4) ◽  
pp. 1094-1099
Author(s):  
Aysen KOC ◽  
Hakan KELES ◽  
Sezai ERCISLI

In this study, fruits from seed propagated walnut (Juglans regia L.) trees were collected two consecutive years in harvest seasons in Yozgat province in Turkey.  Considering two years results, promising five genotypes were determined as cultivar candidate. In the promising genotypes, nut weight ranged from 12.55 (Y11) to 15.08 g (Y15), kernel weight ranged from 5.23 (Y11) to 7.34 g (Y15) and kernel ratio varied between 41.67 (Y11) to 50.84% (Y1), respectively. Linoleic acid was the only polyunsaturated fatty acids and oleic, palmitoleic and gondoic acids determined as major monounsaturated acids ranged from 30.36 to 48.43%, 0.05 to 0.14% and 0.22 to 0.29%, respectively. Propylparaben was the major phenolic acid among the determined phenolic acids in fruits of all five promising genotypes and Y16 had the highest amount of propylparaben (128.08 mg per kg) in its kernel. Malic and tartaric acid were the major organic acids in walnut kernels ranged from 47.88 to 78.51 mg per 100 g and 30.27 to 49.60 mg per 100 g, respectively. L-ascorbic acid was the another organic acids in walnut kernels ranged from 10.71 to 19.71 mg per 100 g. Citric acid was non-determined in kernels of Y1, Y14 and Y15 but determined at kernels of Y11 and Y16 as 4.51 and 7.55 mg per 100 g, respectively. It was determined that the oxalic, malonic, succinic, maleic and fumaric acid contents varied between 8.39-12.08 mg per 100 g, 6.02-9.19 mg per 100 g, 2.86-5.32 mg per 100 g, 0.26-3.00 mg per 100 g and 0.26-0.58 mg per 100 g, respectively.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


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