Population genetic insights into the conservation of common walnut(Juglans regia)in Central Asia

The common walnut(Juglans regia)is one of the most economically important nut trees cultivated worldwide.Despite its importance,no comprehensive evaluation of walnut tree population genetics has been undertaken across the range where it originated,Central Asia.In this study,we investigated the genetic diversity and population structure of 1082 individuals from 46 populations across Central Asia.We found moderate genetic diversity of J.regia across Central Asia,with 46 populations clustered into three groups with a weak relationship between genetic and geographic distance.Our findings reveal that the western Himalaya might be the core region of common walnut genetic diversity in Central Asia and that,except for two populations in Gongliu Wild Walnut Valley,humans might have introduced walnut populations to Xinjiang,China.The observed distribution of the genetic landscape has probably been affected by historical climate fluctuation,breeding system,and prolonged anthropogenic activity.We propose the conservation of the core genetic diversity resources in the western Himalaya and pay special attention to populations from Gongliu in Xinjiang.These findings enhance our understanding of the genetic variation throughout the distribution range of J.regia in Central Asia,which will provide a key prerequisite for evidence-based conservation and management.

Two new glucosides from the pellicle of the walnut (Juglans regia)

A newα-tetralonyl glucoside,6'-O-acetyl-juglanoside E(1),and a new dihydrophaseic acid glucoside,dihydrophaseic acid 1-O-(6-O-acetyl)-glucopyranoside(2),together with two known ones,juglanoside E(3)and dihydrophaseic acid(4),were isolated from the pellicle of the walnut(Juglans regia).The structures of the new compounds were elucidated by comprehensive spectroscopic analysis,including IR,HRESIMS,1D and 2D NMR data.

Antioxidant,antimicrobial,and α-glucosidase inhibitory activities of saponin extracts from walnut(Juglans regia L.) leaves

Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.

Effect of Fertilizer Application on the Yield of Walnut (Juglans regia L.)

[Objectives] This study was conducted to explore the fertilization ratio of walnut, so as to provide a basis for rational fertilization of walnut. [Methods] Under the condition of gravelly yellow soil in Chaotian District, Guangyuan City, the orthogonal design of L_9(3~4) was used to test the fertilization ratio of nitrogen, phosphorus and potassium fertilizers. [Results] The effects of nitrogen, phosphorus and potassium fertilizers on walnut yield ranked as phosphate fertilizer>potassium fertilizer>nitrogen fertilizer. The different treatments had great effects on the yield of walnut, and for the land with gravelly yellow soil, the suitable annual fertilization amount of walnut was urea 1 200 g/plant + calcium superphosphate 1 500 g/plant + potassium sulfate 940 g/plant. [Conclusions] This study provides a theoretical basis for rational fertilization of walnut in Sichuan Province.

Isolation and Characterization of Novel Microsatellite Markers in Walnut (<i>Juglans regia</i>L.)

Thirteen microsatellite markers were isolated and characterized from Juglans regia L. Successful polymorphism of the 13 primer pairs was observed in various genotypes of J. regia. The number of polymorphic alleles ranged from 2 to 4 (with an average of 4.35). The polymorphic information content values ranged from 0.47 to 0.88 (with an average of 0.69). TC/AG and GAA/CTT class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats, respectively.

Gene flow among wild and cultivated common walnut(Juglans regia)trees in the Qinling Mountains revealed by microsatellite markers

Patterns of gene flow and gene introgres sion can be used to assess the risk of genetic pollution of wild forest trees from widespread cultivated trees.A comprehensive understanding of the genetic relationships and levels of gene flow among wild and cultivated common walnut(Juglans regia)has become an urgent issue.Using twelve microsatellite markers,we investigated the genetic diversity and gene flow between cultivated and wild trees of J.regia in the Qinling Mountains,China.A high level of genetic variation was detected in both cultivated and wild trees.The mean number of alleles per locus was 17.5.Observed heterozygosity(HO)and expected heterozygosity(HE)were 0.777 and 0.800,respectively.Pollination of mother trees was not by nearest neighbors,and a paternity of 60.7%of offspring evaluated could not be assigned to a local,sampled tree.Pollen flow from cultivated trees to wild trees was infrequent(5.4%),and selfing rates ranged from zero to 25.0%.Male parents were located from 0 to 1005 m from their female partners,with an average pollination distance of 285.1 m.These results are discussed in light of the cultivated species’diversity,outlining the frequent spontaneous genetic contributions from the wild to the cultivated compartment.In addition,the pollen flow parameters provide useful information about the dynamics of pollen movement within J.regia populations.

核桃(Juglans regia)SRAP标记反应体系建立的研究

以核桃早实优系“绿园”和晚实优系“绿丰”及其F1杂交后代为试材,对核桃SRAP标记反应体系及SRAP标记在核桃中的多态性进行了研究。Mg2+是影响SRAP-PCR反应的重要因子,当Mg2+浓度为2.5mmol/L时,能得到较好的扩增效果。利用11对引物组合对两亲本及其杂交后代进行了SRAP-PCR扩增,以引物组合Em10-Me4多态性最高,在154个杂交后代单株中,扩增出1509条DNA条带,其中多态性条带为824条,多态性比率达54.6%。结果表明,SRAP标记可广泛应用于核桃的遗传多样性分析、种质鉴定、遗传连锁图谱的构建等方面的研究。

核桃(Juglans regia L.)青皮提取物抗氧化及抑菌活性的研究

核桃青皮是核桃(Juglans regia L.)加工的副产物,因含有多种活性成分,可能是一种潜在的天然抗氧化剂和抑菌剂来源。本研究旨在研究核桃青皮提取物的抗氧化能力和抑菌活性,为开发新的饲用抗生素替代品提供参考。以蒸馏水及25%、50%、75%和100%的甲醇、乙醇,丙酮为溶剂分别提取8和12h获得核桃青皮提取物。通过测定提取物中的总酚和总黄酮含量,根据还原能力和2,2-二苯基-1-苦肼基(DPPH)自由基清除率评价其抗氧化能力;以大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌为受试菌,分别测定抑菌圈直径、最小抑菌浓度(MIC)及抑菌率评价其抑菌活性。结果表明,有机溶剂浓度显著影响提取物中的总酚和黄酮含量(P<0.01);除丙酮外,提取时间对提取物中总酚和黄酮含量均有显著的影响(P<0.05);在所有提取溶剂中,以25%乙醇提取8h获得的总酚和黄酮最高,分别达到25.35和12.63mg·g-1。有机溶剂浓度对提取物的还原能力具有显著的影响(P<0.01),而提取时间仅对丙酮提取物的还原能力具有显著影响(P<0.05),其中25%乙醇提取物的还原能力在各处理中最高,为0.366。有机溶剂浓度对提取物的DPPH自由基清除率具有显著的影响(P<0.01),而提取时间仅对甲醇提取物的自由基清除率有显著影响(P<0.01),其中75%丙酮提取物可清除88.81%的自由基,在各处理中最高。有机溶剂浓度对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌的抑菌圈直径和最小抑菌浓度(MIC)均有显著的影响(P<0.01);从提取时间来看,除甲醇提取物对大肠杆菌以及丙酮提取物对枯草芽孢杆菌的抑菌圈直径无显著影响外(P>0.05),其他均有显著的差异(P<0.01);此外,提取时间显著影响对大肠杆菌的MIC(P<0.05),乙醇和丙酮提取物的金黄色葡萄球菌MIC以及丙酮提取物的枯草芽孢杆菌MIC有显著差异(P<0.05),其他提取物的MIC均不受提取时间的影响(P>0.05)。抑菌率测试结果表明核桃青皮25%乙醇提取物对枯草芽孢杆菌的抑菌活性强于对大肠杆菌和金黄色葡萄球菌的抑制。由此可见,所有核桃青皮提取物均具有一定的抗氧化及抑菌活性,尤其以25%乙醇8h提取物的作用最好。

核桃(Juglans regia L.)维生素E代谢相关基因jrVTE3的克隆与分析

核桃(Juglans regia L.)坚果是重要的天然维生素E源。在维生素E合成代谢中,2-甲基-6-叶绿基-1,4-苯醌甲基转移酶(MPBQMTase)催化2-甲基-6-植基-1,4-苯醌(MPBQ)向2,3-二甲基-5-植基-1,4-苯醌(DMPBQ)的合成,是γ-生育酚和α-生育酚生物合成过程中的关键酶。本研究以‘香玲’核桃开花后90 d的胚组织为材料,利用RACE技术克隆了核桃MPBQMT的cDNA。序列分析表明,得到的cDNA全长1280 bp,有1020 bp的开放阅读框(ORF),编码340个氨基酸,将其命名为jrVTE3。序列同源性比较显示,jrVTE3基因与毛果杨MPBQ/MSBQ甲基转移酶基因以及蓖麻、葡萄、大豆的内膜包装蛋白基因有同源性较高;其ORF编码的多肽序列与橡胶、莴苣、毛果杨的MPBQ/MSBQ转移酶及葡萄、蓖麻的内膜包装蛋白有较高的同源性。jrVTE3编码的多肽序列中,有15个氨基酸可能为蛋白激酶磷酸化位点,多肽序列二级结构中有α–螺旋、无规则卷曲。在多肽序列中,有一个低成分复杂性区域和一个跨膜区段,还有一个第一类S-腺苷甲硫氮酸甲基转移酶(AdoMet-MTases,Class I)的保守域,这些序列结构体现了甲基转移酶结构的特点。这些结果对进一步研究核桃坚果仁中维生素E的合成的调控机制及核桃品质的遗传改良具有参考意义。

基于SSR标记的中亚生态区核桃(Juglans regia L.)遗传多样性与种群结构分析

【目的】从分子水平探究中国新疆与吉尔吉斯斯坦和塔吉克斯坦2个中亚国家共6个区域核桃种质资源间的遗传多样性及亲缘关系。【方法】采用SSR分子标记方法对采自6个区域的137份核桃种质资源进行遗传多样性和居群遗传结构分析。【结果】利用14对引物共检测到130个等位变异位点,变异范围为6~13,平均每对SSR引物可检测到9.2857个等位位点;14个SSR位点的占比范围为0.6257~0.8651,平均值0.7634;平均Shannon’s多样性指数(I)为0.4598;种群总基因多样性(Ht)平均值为3.2481;种群内基因多样性(Hs)平均值为2.1089;种群间的遗传分化指数(Gst)范围为0.0578~0.4068,平均值为0.2595;基因流(Nm)平均值为3.0174;各个等位基因频率整体分布不均匀。UPGMA聚类结果显示,137份供试材料在遗传相似性系数为0.75时分成3个类群。其中,第一类群共42份,包括中国新疆阿克苏地区16份,中国新疆和田地区21份,吉尔吉斯斯坦5份;第二类群共44份,包括中国新疆伊犁地区12份、吉尔吉斯斯坦32份;第三类群共51份,包括中国新疆喀什地区19份、塔吉克斯坦13份和中国新疆伊犁地区19份。聚类结果在一定程度上表明了居群间亲缘关系的距离,总体分布与地理分布有关,不同区域之间存在一定的基因交换。聚类结果与居群间遗传距离和遗传一致度结果一致。【结论】SSR分子标记结果表明,中亚生态区不同地理分布的核桃种质资源遗传多样性存在差异,为揭示中亚生态区核桃种群结构及传播途径提供了依据。

核桃(Juglans regia L．)光合影响因子的研究

以普通核桃'清香'为试材,利用CI-301PS便携式光合作用测定仪,在田间条件下,测定了核桃净光合速率的日变化及季节变化,进行了核桃净光合速率与光合影响因子的相关性研究,为核桃栽培管理提供一定的科学依据。结果表明:核桃净光合速率日变化与叶温极显著正相关,与光合有效辐射、蒸腾速率、气孔导度显著正相关,与胞间CO_2浓度极显著负相关。核桃净光合速率季节变化与蒸腾速率呈极显著正相关,与叶绿素含量呈显著正相关,与胞间CO_2的浓度呈显著负相关。

Two new diarylheptanoids from the pericarps of Juglans regia L.

Two new cyclic diarylheptanoids juglanin A （1） and juglanin B （2） were isolated from the pericarps of Juglans regia L. Their structures were elucidated by various spectroscopic methods including 2D NMR techniques （COSY, HMQC, HMBC, NOESY） and HR-ESIMS.

In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia

Abstract Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine.

Anti-diabetes Agents——I:Tetralone Derivative from Juglans regia

A new compound, 4-hydroxy-a-tetralone-4-O-b-D-[6-O-(3,4,5-trihydroxybenzoyl) glucopyranoside (1), together with a known compound, 4-hydroxy-a-tetralone (2), has been isolated from the roots of Juglans regia. 2 showed moderate bioactivity against protein tyrosine phosphatase 1B (PTP1B).

我国核桃组(Sect.Juglans)种质资源的SSR标记分析

为从基因水平对我国核桃组资源的遗传多样性进行分析,用9对SSR引物对核桃组中29份核桃(Juglansregia L.)样品、2份铁核桃(J.sigillata D.)样品、4份J.sigillataD.×J.regiaL.样品进行扩增,共检测出等位基因47个,每个位点扩增3～9个等位基因,平均5.2个。9个SSR位点的PIC值在0.3188～0.7902,平均为0.6357。35个样品在9个SSR位点上有杂合位点1～6个,样品的杂合度在0.11～0.67,平均0.35。采用UPGMA方法进行聚类分析,35个样品可以分为4组。其中陕西晚实核桃与华北核桃聚为一类,陕西早实核桃聚为一类再与新疆核桃聚为一组,表明秦巴山地核桃可能属于华北和新疆2个地理生态型。铁核桃与西藏核桃聚为一组,说明铁核桃与西藏核桃的亲缘关系较近,认为铁核桃和西藏核桃作为核桃种下的一个生态类型可能更为合适。

河北核桃(Juglans hopeiensis Hu)光合特性的研究

以河北核桃‘艺核1号’等为试材,利用CI301PS便携式光合作用测定仪,在田间条件下,研究了河北核桃的光合特性。结果表明:‘艺核1号’光饱合点为1643μmol·m-2·s-1左右,光补偿点为50μmol·m-2·s-1左右,最适温度为29℃;光合速率日变化为“中午降低型”的双峰曲线;净光合速率的季节变化为双峰曲线,第1峰出现在5月中旬,第2峰出现在8月上旬;影响光合速率日变化的主要因子依次是气孔导度、光合有效辐射、叶温、胞间CO2浓度和蒸腾速率。河北核桃净光合速率低于普通核桃,接近于核桃楸。

云南核桃(Juglans sigillata Dode)的物理特性(英文)

云南核桃（Juglans sigillata Dode）是中国西南地区特有品种．在核桃的采收、加工及其设备的设计过程中，其基本物理参数具有重要的指导作用．以云南核桃为研究对象，分别测试和统计了带壳核桃、核桃果仁在不同含水率下的三径（长度、宽度、厚度），几何平均直径，球度系数，表面积，单粒质量、体积，堆积密度，粒子密度．结果表明：当含水率为35.7％～5.3％（湿基）时，带壳核桃的平均长、宽、厚直径分别为38.96～37.18 mm、41.04～39.66 mm、34.92～33.68 mm；几何平均直径38.22～36.68 mm；球度系数93.13％～92.68％；表面积45.89～42.45 cm2；单粒质量18.85～12.80 g；单粒体积29.23～26.00 cm3；堆积密度359.50～301.89 kg/m3；粒子密度754.00～578.66 kg/m3；当果仁含水率为29.8％～5.9％时，其平均长度、宽度、厚直径为29.40～28.14 mm、35.63～33.96 mm、28.43～26.90 mm；几何平均直径为31.00～29.51 mm；球度系数87.25％～86.55％；单粒质量11.85～8.85 g；单粒体积15.59～13.45 cm3；堆积密度623.68～595.96 kg/m3；粒子密度1039.47～936.51 kg/m3．由此可知，云南核桃及其果仁的基本物理参数均随其含水率的降低成线性减小，其中仅有球度系数的变化没有规律性．

Key chemical composition of walnut(Juglans regia.L)Oils generated with different processing methods and their cholesterol-lowering effects in HepG2 cells

We systematically evaluated fatty acids and triacylglycerol composition,as well as tocopherol,phytosterol,and phenolics,in walnut oil and compared the cholesterol-lowering effects of oil processed with different methods(cold pressing,roast-pressing,hexane extraction,subcritical butane extraction,and supercritical CO_(2) extraction).The different methods did not affect the lipid composition of walnut oil.The tocopherol(41.11 mg/100 g)and total phenolic content(TPC,4.26 mg/100 g)of roast-pressed walnut oil and the phytosterol contents of subcritical butane-extracted walnut oil(106.51 mg/100 g)were higher than those of other tested oils.Walnut oil significantly decreased cholesterol synthesis by downregulating the expression of HMGCR,SREBP-2,and CYP51 genes,and increased cholesterol efflux by upregulating the expression of ABCG1,thus significantly reducing total cholesterol and triacylglycerol.Phytosterols and TPC in walnut oil were responsible for lowering cholesterol;the optimal concentration of phytosterols was 10μg/mL,and that of TPC was 12.5×10^(-3)μg/mL.Through process optimization,a new processing method for walnut oil based on biological evaluation was preliminarily established.

Thinning effects on walnut stem and crown diameter growth and fruiting in the walnut-fruit forests of Kyrgyzstan

The walnut-fruit forests （Juglans regia L.） in southern Kyrgyzstan are considered to be biodiversity hotspots and of considerable economic and ecological importance to local populations. The fruiting ability and stability of these forests are, however, decreasing because of infrequent silvicultural interventions and non-existent natural regeneration. Continuous inventories and walnut harvest measurements were carded out on 18 trial and control plots over the course of i3 year. Results showed that i） thinning had a positive influence on diameter at breast height （dbh） increase, ii） dbh growth and crown area increases are strongly and positively correlated, iii） large crowns enhanced the production of fruits, and iv） temperature conditions had a major influence on the production of fruits. The above-mentioned points are particularly relevant for young plantations but are also valid for relatively old plantations （〉 50 years）. We conclude that regular thinning substantially improves diameter growth, fruit production and ability of trees to withstand wind and snow damage in both young stands and in older walnut-fruit forests.

Fatty Acid, Total Phenol and Tocopherol Profiles of Some Walnut Cultivars: A Comparative Study

As a member of nuts, walnut is consumed from snacks to salads and desserts to entrees and an importantpart of human diet for centuries. Walnut biological and nutritional value is also enhanced by its valuable protein and rich in nutrient composition such as vitamins and minerals. The most important characteristic of walnut oil is the abundance of polyunsaturated fatty acids, which makes it a unique food because of high amount of linoleic acid. Due to having valuable protein, vitamins and minerals it enhances biological and nourishment value, also. Recent epidemiological studies showed that consumption of walnut reduce cardiovascular diseases due to the rich in antioxidant properties, valuable fatty acids and tochopherols contents. In Turkey, walnut production and consumption increases year by year. The kernel of walnut genotypes shows variability in terms of their fat, fatty acid and tocopherol profiles. In this paper, it was aimed to characterize 10 walnut (Juglans regia L.) cultivars (Bilecik, Chandler, Hartley, Howard, Maras 12, Maras 18, Midland, Pedro, Sen and Serr) based on their fatty acid profiles using GC (Gas Chromatography), tocopherol and its isomers by HPLC (High Performance Liquid Chromatography) and total phenol content with spectrometric methods. Among the walnut cultivars “Hartley” was the highest linoleic acid (64.56%) and “Howard” was the α-linolenic acid 13.26 (%). The highest values of α (38.76 μg/g), β + γ (312.19 μg/g) and δ-tocopherol (40.77 μg/g) and total phenol (349 mg GAE/100 g ext) content were detected in “Sen” cultivar. Obtained results might be significant for further breeding programme to improve rich in especially γ-tocopherol linoleic acids and total phenolic compounds.