Pomegranate fruits are prone to chilling injury during low temperature storage, resulting in husk browning. In this study, two varieties of pomegranate fruit, 'Jingpitian' and 'Tunisia soft seed' ('Tunisia') were chosen to compare the differences in husk browning after 60 days of storage at 4 +/- 1 degrees C. The transcriptomics was utilized to investigate the causes and differences of husk browning caused by chilling injury. At the end of storage, the relative conductivity of 'Tunisia' was 31.47% lower than that of 'Jingpitian', and the total phenols content was 3.11 times that of 'Jingpitian'. 'Tunisia' showed lower browning index, polyphenol oxidase, and peroxidase activities, and higher cell membrane integrity, phenolics, phenylalanine ammonia-lyase, and catalase activities. The transcriptomics of husk samples indicated that 6329 differentially expressed genes (DEGs) were identified in the two varieties on the 60th day. There were 3453 up-regulated DEGs and 2876 down-regulated DEGs. Additionally, most DEGs were significantly enriched in carotenoid biosynthesis and flavonoid biosynthesis pathways, indicating the two pathways could be related to the husk browning of pomegranate fruits. Collectively, the genes involved in cellular process of 'Jingpitian' were up-regulated, resulting in the destruction of cell membrane integrity. This accelerated the reaction of polyphenol oxidase and phenolics, causing the husk browning. It was noted that the husk browning was accompanied by the degradation of pigments. These findings could provide theoretical support for the study of husk browning caused by chilling injury.

Pomegranate is sensitive to low temperature and is susceptible to chilling injury (CI), resulting in husk browning. The effects of Methyl jasmonate (MeJA), hot water treatment (HWT), and control treatments on the quality of pomegranate fruit during low temperature storage were investigated. The results showed that MeJA and HWT treatments could effectively inhibit the increase of browning index, color difference, relative conductivity, polyphenol oxidase (PPO) and peroxidase (POD) activities, maintain phenolic substances and the activity of phenylalanine ammonia-lyase (PAL). The browning index of MeJA treatment was 55.42 % lower than control treatment on the 70th day, the relative conductivity and MDA content were 24.32 % and 51.67 % lower than control treatment, respectively. Furthermore, MeJA treatment delayed the increase of PgPPO and PgPOD gene expression levels, upregulated the expression levels of PgPAL gene. Overall, MeJA treatment could improve antioxidant capacities, alleviate CI by regulating phenolic metabolism and gene expression levels.

As a native crop in central Asia, pomegranate (Punica granatum L.) has been cultivated in China for more than 2000 years (Yuan et al. 2007). In August 2022, typical symptoms of anthracnose were observed on pomegranate fruitlets in the main cultivation area (34°22'36″N, 109°15'58″E) in Shaanxi Province, China. The disease incidence was approximately 10 to 15% in the field. The initial symptoms were slightly small, light, dark, sunken lesions with irregular, circular shapes. As the disease progressed, the necrotic lesions gradually expanded and merged, eventually leading to the abscission of fruits (Figure 1, A). The symptomatic lesion samples of the pomegranate were sterilized for 1.5 min in 75% ethanol and 2 min in 1% NaClO and rinsed for 2 min in sterile water three times. The sterilized samples were dried on sterile filter paper and placed on potato dextrose agar (PDA) media at 25 ℃ for 5 days. The mycelia of the isolate were white, cottony, and diffuse (Figure 1, B and C). The conidia were single-celled, smooth, aseptate, and cylindrical with slightly rounded ends, measured 13.5 to 17.5 μm long and 3.5 to 6.5 μm wide (mean 16.0 × 4.5 μm, n = 50) (Figure 1, D). These morphological characteristics were identical to those of Colletotrichum siamense (Weir et al. 2012; Cannon et al. 2012; Zhuo et al. 2022). For accurate molecular characterization of the fungus, genomic DNA was extracted from the hyphae of the two isolates using microorganism lysis buffer (Takara, Japan). The internal transcribed spacer (ITS), calmodulin (CAL), actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and beta-tubulin (TUB2) regions were amplified and sequenced. All the sequences were submitted to GenBank with accession numbers OQ832556 (ITS), OQ848589 (GAPDH), OQ848590 (ACT), OQ848591 (CAL), and OQ986593 (TUB2). The isolates showed 99 to 100% identity with sequences of Colletotrichum siamense (100% with GAPDH, ACT, CAL, and TUB2; 99.81% with ITS). The morphology of the strain was studied, and multilocus (ITS, GAPDH, ACT, CAL, and TUB2) phylogenetic analysis was performed (Figure 2). Therefore, the causal pathogen was identified as C. siamense based on the results of morphological and molecular analyses. Pathogenicity assays were performed on pomegranate (cv. Lishanhong) fruits. A conidial suspension (1×106 conidia/mL) was sprayed onto 10 unwounded fruits to inoculate them as infected samples, and the controls were inoculated with a sterile water suspension. All the samples were maintained in an artificial climate box at 25 ± 2 ℃ with 70% relative humidity, and the photoperiod was set as 12:12 light:dark. After 5 to 7 days, anthracnose symptoms developed on the surface of the inoculated fruit, whereas the control fruits remained healthy. The diseased fruits exhibited brown necrotic lesions, whereas the upper surfaces of the control fruits remained asymptomatic. The morphological and molecular characteristics of the reisolated pathogen were identical to those of the original fungus isolated from the natural fruit. C. siamense has been reported to cause anthracnose in the southeastern United States (Xavier et al. 2019). The pathogen causing anthracnose on pomegranates has been reported to be Colletotrichum fructicola in China (Hu et al. 2023). To our knowledge, this is the first report of anthracnose on pomegranate fruits caused by C. siamense in China. This disease can directly affect the quality and yield of the fruit. Thus, information about the characteristics of this disease could provide a theoretical basis for its prevention and control.

The deterioration degree of pomegranate husk, aroma components and antioxidant contents of pomegranate juice have important effects on postharvest storage quality and vary among cultivars. At the present study, 'Tunisia soft seed', 'Jingpitian' and 'Lishanhong' cultivars from Shaanxi, China was used as raw materials. They were stored at 4 +/- 0.5 degrees C and 85-90% relative humidity for 90 d which aimed to elucidate storability differences. Both husk changes and storage quality were monitored. Our results showed that 'Tunisia soft seed' maintained a good microstructure in husk and possessed a high value of soluble solids/titratable acid ratio and high contents of antioxidants (total phenols, total flavonoids, total anthocyanins, vitamin C) but suffered from high moisture and volatile aroma compounds losses. 'Jingpitian' exhibited lower moisture and aroma compounds losses, but showed significant husk browning, micro-cracks widening, lenticels blocking and wax layer disintegrating. 'Lishanhong' showed similar fruit quality characteristics to 'jingpitian'. These findings will contribute to eluci-dating the appearance change, microstructure and fruit quality differences among cultivars in postharvest pomegranates during cold storage and providing help for enterprises to discriminate and select varieties suitable for fresh sales or storage.

Cold storage is one of the most commonly used ways to store pomegranates(Punica granatum L.).Husk browning can occur during cold storage due to phenolic metabolism and energy decay.Three pomegranate cultivars grown in Shaanxi:the introduced cultivar'Tunisia soft seed',the traditional cultivar'Jingpitian'and the newly bred cultivar'Lishanhong'were used to explore the relationship between husk browning and phenolic and energy metabolism under storage conditions of(4.0±0.5)℃and 85%-90%relative humidity,and the storage characteristics of these cultivars were compared.The results showed that with the extension of storage time,browning index increased,1,1-diphenyl-2-picryl-hydrazyl(DPPH)radical scavenging capacity increased at first and decreased later,2,2'-azino-bis-3-ethylbenzothiazoline 6-sulfonic acid(ABTS)cation radical scavenging capacity,total phenol and flavonoid contents fluctuated only slightly,and anthocyanin content increased at first and then decreased for all cultivars.Among them,the contents of total phenols,total flavonoids and anthocyanins were highest in'Tunisia soft seed'pomegranates.During storage,polyphenol oxidase(PPO)activity remained lowest,and phenylalanine ammonialyase(PAL)activity remained highest in'Tunisia soft seed'pomegranates.Peroxidase(POD)activity was always highest in'Jingpitian'pomegranates.In addition,'Tunisia soft seed'pomegranate husk maintained higher adenosine triphosphate(ATP)and adenosine diphosphate(ADP)contents and energy charge,as well as higher Mg2+-ATPase and H+-ATPase activities during storage.The correlation analysis showed that the browning index of'Jingpitian'pomegranate husk,which was highest among the three cultivars,was significantly positively correlated with total phenol and flavonoid contents,POD and PAL activities,and ATP and ADP contents(P<0.05 and P<0.01);the browning index of'Tunisia soft seed'pomegranate husk,which was lowest,was significantly positively correlated with POD activity and the content of adenosine monophosphate(AMP)(P<0.01);and the browning index of'Lishanhong'pomegranate husk,which was in the middle,was significantly positively correlated with total phenol and AMP contents(P<0.05 and P<0.01,respectively)but significantly negatively correlated with Mg2+-ATPase activity(P<0.01).Principal component analysis(PCA)showed significant quality differences between'Tunisia soft seed'pomegranates and the two other cultivars.The above findings demonstrated that the browning degree of pomegranate husk under cold storage conditions varied among cultivars and was related to phenolic and energy metabolism.

石榴(Punica granatum L.)属石榴科(Punicaceae)石榴属(Punica),具有很高的营养价值和药用价值.石榴干腐病(Pomegranate dry rot)是由植物病原真菌引起的症状相似的一类破坏性病害,可危害花器、果实和枝干,是我国石榴生产中的重要病害.多年来的研究结果表明,多种病原菌均可引起石榴干腐病.石榴干腐病的发生因产地、地理条件而异,且同一病原发生的地域范围也不同.目前,关于石榴干腐病病原菌的研究结果存在较大分歧.在生产中,针对石榴干腐病的防治主要还是依赖栽培管理及化学药剂防治进行病害控制,针对石榴干腐病生物防治研究工作仍处于实验室活性菌株筛选及活性评价的初步研究阶段.本文概述了石榴干腐病发病规律、症状特征、病原菌研究进展、生物学特征及相关防治技术研究进展,并对当前相关研究进展与技术应用中存在的问题进行了探讨,以期为该病害的深入研究及有效防治提供参考.

[目的]由于石榴冻害的综合气候指标研究相对较少,这就造成石榴气象服务存在一定局限性.且石榴冻害指标分级制订存在差异,缺乏统一标准,不利于石榴冻害监测预报预警和灾情评估.因此,对临潼石榴冻害综合气候指标进行分析,为石榴冻害的监测预报预警服务和灾情评估提供技术支撑.[方法]通过实地走访、资料查阅等方式调查石榴冻害灾情,建立临潼石榴冻害综合气候指标分级标准.基于1991—2020年37个冻害实例,运用主成分分析、K-means聚类分析,对临潼石榴冻害综合气候指标进行研究分析.[结果]极端最低气温、低温持续日数、过程有害积寒与石榴冻害密切相关,通过对石榴冻害数据标准化处理,构建石榴冻害综合气候等级指标(Z),包括:轻度,-7.56≤Z<-6.77;中度,-8.36≤Z<-7.56;重度,Z<-8.36.通过与典型年对比验证,并进行智能网格预报应用,发现实际发生的冻害情况与本文建立的临潼石榴冻害综合气候等级指标吻合较好,为气象服务石榴高质量发展提供模式支撑.[结论]通过典型年对比验证及智能网格预报应用,石榴冻害综合气候指标能较好的预报预测石榴冻害风险,为气象服务石榴高质量发展提供模式支撑.但暂未对临潼石榴遭受冻害后的植物生理指标进行测定,其他气象因子对石榴冻害的影响程度及其指标建立和等级划分等工作,还有待今后进一步研究.

秦岭地区自然资源丰富,素有"南北植物荟萃、南北生物物种库"之美誉.特别是以猕猴桃为代表的野生果树资源,堪称第2、第3代新型水果开发的生物基因库,是良种选育利用的重要基础.

[目的]明确不同年龄时期石榴园土壤养分、土壤微生物量、土壤酶活性状况,为不同年龄时期的石榴园土壤管理提供参考依据.[方法]采集陕西石榴主产区处于生长期、结果初期和盛果期三个年龄时期的石榴园土样,测定土壤养分、土壤微生物量以及土壤酶活性,并分析它们之间的相关性.[结果]① 陕西石榴主产区土壤中碱解氮的含量在结果初期和盛果期显著高于生长期,但整体含量均较低;速效磷和速效钾含量随石榴树年龄增加显著递增,且速效磷的含量在各年龄时期均较高,而速效钾的含量仅在生长期偏低.② 微生物数量随石榴树年龄增加逐渐增多,且细菌数量显著递增,而真菌数量和放线菌数量在结果初期和盛果期均显著高于生长期,但在结果初期和盛果期之间无显著性差异.③ 土壤脲酶、蔗糖酶和碱性磷酸酶活性随石榴树年龄显著递增,而过氧化氢酶活性则显著递减.④相关性分析结果表明,土壤脲酶、蔗糖酶和碱性磷酸酶活性与土壤中的细菌和真菌数量正相关,而过氧化氢酶活性则与土壤中的细菌和真菌数量负相关;仅蔗糖酶与放线菌数量显著相关;这四种酶活性均与碱解氮、速效磷以及速效钾含量显著相关;真菌及放线菌数量均与碱解氮、速效磷和速效钾显著相关,而细菌数量与速效磷和速效钾极显著相关,但与碱解氮没有显著相关性.[结论]不同年龄时期的石榴园土壤养分、土壤微生物数量及土壤酶活性具有一定的差异,而且土壤微生物数量及土壤酶活性均与土壤养分密切相关.

目的 研究茉莉酸甲酯对石榴贮藏品质的影响,为延长石榴货架期提供依据.方法 以临潼"净皮甜"石榴为实验材料,采用不同浓度茉莉酸甲酯(0.01,0.05,0.1 mmol/L)对石榴果实进行熏蒸处理,然后转入(4±0.5)℃冷库贮藏56 d.结果 在整个贮藏期间内,茉莉酸甲酯处理可延缓石榴硬度、可溶性固形物含量、总糖含量、可滴定酸含量、感官品质的下降,抑制石榴果皮褐变指数和质量损失率的上升,并能提高CAT,POD,PAL,GLU等的酶活性.实验得出,当茉莉酸甲酯浓度为0.05 mmol/L时处理效果最好.结论 茉莉酸甲酯处理是一种有效保持石榴贮藏品质、延长货架期的方法.

突尼斯软籽石榴在贮藏过程中容易出现果皮褐变、籽粒变质、软化腐烂等问题,严重影响果实的商品价值.以陕西潼关突尼斯软籽石榴为试材,研究低温结合1-甲基环丙烯(1-methyl-cyclopropene,1-MCP)处理对采后突尼斯软籽石榴品质的影响,即在贮藏温度(3±0.5)℃、相对湿度90％ ～95％条件下,选用0.2、0.5、1.0、1.5 mg/L四种不同质量浓度的1-MCP处理软籽石榴,贮藏期间每20 d测定石榴果实的可滴定酸、可溶性固形物、还原糖含量,呼吸强度、相对电导率、褐变指数及多酚氧化酶、过氧化物酶活性,并计算果实失重率和腐烂率,贮藏120 d时对软籽石榴的感官性状进行综合评价.结果表明,采用1.0 mg/L的1-MCP处理软籽石榴能有效减缓果实腐烂变质,减缓果实呼吸强度,降低褐变指数,较好地保持籽粒可溶性固形物、可滴定酸及还原糖含量,并使多酚氧化酶、过氧化物酶活性处于较低水平,降低果实失重率和腐烂率,保持良好的感官品质.突尼斯软籽石榴适宜的贮藏条件为:贮藏温度(3±0.5)℃、相对湿度90％ ～95％、1-MCP处理质量浓度1.0 mg/L,并用聚乙烯塑料袋密封包装,保鲜效果理想.

以陕西临潼"净皮甜"石榴为原料,研究石榴果实经低温结合薄膜包装处理后采后生理和贮藏品质的变化,为后续石榴贮藏保鲜提供技术参考.石榴经预冷后,用厚度0.01 mm的聚乙烯(polyethylene,PE)塑料保鲜膜单果覆膜包装,分别置于(0±0.5)℃、(4±0.5)℃和(8±0.5)℃、相对湿度90％ ～95％的冷库中贮藏.以未经薄膜包装处理贮藏的石榴作对照,贮藏期间每隔30 d随机取样测定果实可溶性固形物含量、可滴定酸含量、VC含量、呼吸速率、相对电导率、褐变指数、失重率、腐烂率,并进行感官评价.结果表明,石榴采用厚度为0.01 mm聚乙烯薄膜包装,在温度(4±0.5)℃条件下贮藏,能有效地保持果实的可溶性固形物含量、可滴定酸含量和VC含量,抑制果实呼吸作用,减缓果皮相对电导率和褐变指数升高,降低果实失重率和腐烂率.贮藏120 d时果实外观色泽鲜艳,籽粒感官品质良好,保鲜效果理想.(4±0.5)℃下经0.01 mm聚乙烯薄膜包装可以有效延长石榴贮藏期.

西安所在的陕西关中地区是世界第一代果树桃、杏、李、枣、栗等的原产地,也是中国石榴、葡萄等引进果树的原生地.果业是西安农林业的特色和标志性产业,是西安都市型现代农业发展、农民增收致富支柱产业,也是西安的一张新名片.

Modified atmosphere storage can regulate the reactive oxygen metabolism of fruits and vegetables, reduce the accumulation of hazardous free radicals, and mitigate the peroxidation degree of fruit membrane lipids. In this study, different gas matching ratios were adopted for the modified atmosphere treatment of pomegranate fruits. Up to 120 d of storage, compared with the control treatment, the H2O2 and malonaldehyde (MDA) contents in treatment 2 decreased by 8.88% and 18.28%, respectively, when the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbic acid peroxidase (APX) in treatment 2 increased by 21.44%, 117.38% and 114.95%, the ascorbic acid (ASA) and glutathione (GSH) contents in treatment 2 also increased by 116.83% and 50%, these results showed that treatment 2 (6.0% O2, 6.0% CO2) could effectively regulate various indexes of the reactive oxygen metabolism of pomegranate peels, maintain the normal physiological actions of the fruits, and postpone the ripening and senescence of histocytes. Under treatment 4 (10.0% O2, 10.0% CO2), H2O2 contents in the pomegranate peel significantly increased, and the activities of SOD, CAT and APX significantly reduced. ASA and GSH were degraded, the MDA content abruptly increased, the membrane lipid peroxidation accelerated, and the cytomembrane structure was destroyed.

为三叶木通的推广应用与品种选育提供参考,采用现代分析技术,对西安市鄂邑区三叶木通种植园4个三叶木通品种的生物学性状及果实中果肉、籽粒、果皮的化学成分进行分析.结果 表明:果肉富含可溶性固形物、蛋白质、脂肪、总酸还原糖和必需氨基酸;籽粒中油脂和不饱和脂肪酸含量分别为45.40％～48.07％和74.27％～76.47％.果皮中富含果胶、多酚、黄酮等活性物质.果肉、籽粒及果皮均可利用.深紫色品种最优,其果形最大、单果最重(250.80 g/个),果面光滑圆润,肉质细腻透亮,甘甜鲜美,果肉占比最高,为23.49％;果皮占比最低,为61.52％;籽粒最多,为240粒/个;果肉中必需氨基酸含量最高,为200.86 mg/100g;籽粒中粗脂肪含量最高,为48.07％.可对深紫色品种通过特殊育种技术,筛选无籽(少籽)的三叶木通品种,或选育籽多、油脂含量高的加工品种加以应用.

通过对陕西省内石榴园内害虫进行调查,记述了危害陕西石榴的2种缨翅目新害虫,包括西花蓟马和梳缺花蓟马.同时,对该2种害虫的形态、寄主、分布、危害部位、发生时间和防治方法作了简述.

作为丝绸之路起点的西安, 是我国葡萄的发源地和次生中心,也是葡萄栽培优生区.以户太八号为代表的葡萄产业, 是西安市都市型现代农业优势产业. 1 西安葡萄产业发展历史 1.1 产业形成阶段 西安是我国葡萄栽培历史最为悠久的地区之一.过去的西安产区,以欧亚种葡萄品种为主, 葡萄是农民房前屋后庭院经济的代表作物. 上世纪70年代,西安开始规模化栽植葡萄. 至上世纪80年代中后期,长安滦镇建成了以白香蕉为主的葡萄鲜食加工基地, 灞桥区建成了以巨峰为主的大粒鲜食葡萄基地,西安市葡萄总面积达到1000亩. 此时,巨峰系葡萄大量引入西安, 逐渐形成了以欧美杂交种为主的品种发展格局. 农民育种家纪俭在户县(今鄠邑区)草堂镇太河园艺场选育发现了户太八号葡萄优株.

陕西是我国石榴种质资源最丰富的地区,现有石榴15万亩以上,主要分布在关中地区,以西安市临潼区、咸阳市礼泉县、渭南市潼关县出产的石榴最为有名,这三大石榴主产区总面积10万多亩.针对目前石榴产业存在规划滞后导致产区发展目标不明确,产区间发展同质化严重,特色不突出的问题,我们提出了陕西石榴产业发展规划及产业升级技术优化建议.

八月炸是木通科木通属植物木通、 三叶木通、白木通的成熟果实,具有极高的营养价值和显著的保健功能. 1 八月炸资源分布与利用现状 1.1 资源类型与分布 八月炸(图1)别名有八月札、八月瓜、野木瓜、野香蕉、九月炸、北方土香蕉、瓜蕉、合欢果、中华肾果、狗腰子、桴枝子、木通子、预知子、玉知子、野毛蛋、冷饭包、羊开口、腊瓜等. 木通属植物有4个种4个变种,分布于中国和日本,为典型的东亚分布区类型.我国的华中地区为其分布中心, 陕西产1个种2个变种.

目前, 周至及陕西猕猴桃产业正处于转型升级关键期. 2018年,周至及周边地区突然兴起用水杨桃作砧木发展猕猴桃之风, 民间盛传该砧木可以抗水渍,预防溃疡病,是支撑猕猴桃产业发展的新型砧木.针对这个情况,我们组成课题组深入产区进行了调查.