The PcERF5 promotes anthocyanin biosynthesis in red-fleshed pear(Pyrus communis)through both activating and interacting with PcMYB transcription factors

As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm,primarily found in European pears(Pyrus communis).In this study,based on transcriptomic analysis in red-fleshed and white-fleshed pears,we identified an ethylene response factor(ERF)from P.communis,PcERF5,of which expression level in fruit flesh was significantly correlated with anthocyanin content.We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.On the one hand,PcERF5 can activate the transcription of flavonoid biosynthetic genes(PcDFR,PcANS and PcUFGT)and two key transcription factors encoding genes PcMYB10 and PcMYB114.On the other hand,PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis,which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.This new knowledge will provide guidance for molecular breeding of red-fleshed pear.

New Variants of Wild Red-fleshed Kiwifruit in Jiugongshan Region and Their Application Prospect

The collection of wild kiwifruit germplasms has already proved its worth with the development of valuable new kiwifruit cultivars.Through field investigation and consulting the existing literature,this paper illustrates that Jiugongshan region in China is a unique gene bank of excellent wild kiwifruit germplasm resources on the boundary between Hubei and Jiangxi provinces.It is also one of the important birthplaces of breeding materials for new kiwifruit cultivars in China.The paper introduces the main characteristics of two wild red-fleshed kiwifruit germplasms discovered in this region,and one of them is a new large-fruited variant of wild red-fleshed kiwifruit.The main fruit qualities of the large-fruited form are that short fruit stalk,large fruit(the maximum fresh fruit mass of about 81.2 g),moderate sweetness and sourness,reddish to red inner pericarp,the ripe fruit soluble solids content 14.10%,total sugar 8.84%,total acid 1.18%,vitamin C 644.3 mg/kg.It is expected to be cultivated into a new edible cultivar(line)or ornamental and edible cultivar(line)of Actinidia chinensis,which has a broad prospect of development and utilization.

Pathogenic Identification of Leaf Tip Blight of Red-fleshed Kiwifruit in Qiandongnan Prefecture

[Objective]The paper was to investigate and identify new diseases in kiwifruit producing areas in Qiandongnan Prefecture to reduce the harm of diseases and ensure the quality of red-fleshed kiwifruit products.[Method]The pathogenic fungus was isolated from diseased leaves of redfleshed kiwifruit by tissue separation method,and DNA was sequenced by ribosomal rDNA-ITS(internal transcribed spacer)sequencing.Molecular evolutionary trees were built using MEGA4.0 software,and the pathogenic fungus was classified and identified combined with morphological obser-vation.[Result]Leaf tip blight was a new disease caused by Epicoccum sorghinum.It caused serious damage on red-fleshed kiwifruit.[Conclusion]The study supplements diseases of red-fleshed kiwifruit,and provides support for disease prevention and control in late stage.

Identification of Pathogens on Dry Blight Disease in Leaf Tip of Red-fleshed Kiwifruit in Qiandongnan Prefecture

In order to reduce the harm of diseases in red-fleshed kiwifruit in Qiandongnan Prefecture and ensure product quality, a new disease in the producing areas were investigated, and pathogen identification were carried out. The pathogen was isolated from diseased leaves by a tissue separation method. DNA sequencing was performed by the sequence analysis of ribosomal rDNA-ITS(Internal transcribed spacer) region, and a molecular evolutionary tree was constructed by the MEGA 4.0 software. The pathogenic fungus was classified and identified by combining morphological observation finally. The results showed that the dry blight disease in leaf tip was a new disease, which was caused by Epicoccum sorghinum, and it had a serious damage to red-fleshed kiwifruit.

Unraveling betalain suppression in pitaya:insights from co-activator HuMYB9 binding at HuCYP76AD1-1,HuADH1,and HuDODA1 super-enhancers

Objectives:Myeloblastosis(MYB)proteins,recognized as crucial transcriptional regulators,play an integral role in orchestrating the range of plant colors.Materials and Methods:Pitaya(Hylocereus spp.),a distinctive commercially cultivated fruit,stands apart due to its unique betalains,water-soluble nitrogen-enriched pigments that confer its vibrant hues.Although betalain biosynthesis has been extensively explored,the potential infuence of co-activators that might disrupt pigment production remains relatively unexplored.Results:In this study,we found that HuMYB9,an R2R3-MYB repressor,exhibited a remarkable decreasing during pitaya maturation.Sequence alignment analyses showed conserved R2 and R3 domains within the C-terminal of HuMYB9.HuMYB9’s regulatory activities were found to be nuclear localized and it interacted with specifc elements within the promoters of HuDODA1,HuADH1,and HuCYP76AD1-1,thus infuencing the transcriptional activities in vitro.HuMYB9 transiently downregulated the expression of key betalain biosynthetic genes with a corresponding effect on the levels of pitaya pulp betalains.Conclusions:Our results suggest that HuMYB9 operates as a suppressor,specifcally downregulating the expression of HuCYP76AD1-1,HuDODA1,and HuADH,thereby modulating betalain biosynthesis in pitaya.Collectively,our fndings provide invaluable insights into the regulation of betalain accumulation in pitaya.

外源褪黑素对火龙果果实采后保鲜的影响

本研究以大红火龙果为试验材料,经不同浓度的褪黑素MT(0.2、0.4、0.8 mmol/L)处理,在温度(7±1)℃、相对湿度75%~85%的条件下贮藏,明确MT对其保鲜效果的影响。结果表明:0.2、0.8 mmol/L MT处理有效降低了火龙果果实腐烂率(DI),MT处理能有效降低呼吸速率(RR),抑制相对电导率(RC)的增加。0.2 mmol/L MT可有效延缓抗坏血酸(AsA)含量下降,抑制丙二醛(MDA)含量的增加及过氧化氢(H_(2)O_(2))、超氧阴离子(O_(2)^(-))的生成,提高抗氧化酶(SOD、CAT、APX)活力,有效促进活性氧(ROS)代谢,清除自由基,提高果实抗氧化能力。同时,0.2 mmol/L MT可有效维持抗病相关酶(PAL、POD、PPO)活力,从而诱导提高火龙果果实抗病能力。此外,0.2 mmol/L MT能增加可溶性糖(SS)、类黄酮(flavonoids)含量,但CK和MT处理果实的失重率(WLR)无显著差异。相关性分析表明,19个指标间存在显著相关性且火龙果果实腐烂率与ROS代谢紊乱、膜质过氧化密切相关。主成分分析表明,0.2 mmol/L MT处理的火龙果各贮藏时期得分均高于CK,且其累计综合评分最高,表明其综合保鲜效果最好。综上,0.2mmol/LMT处理主要通过维持ROS代谢平衡及提高火龙果果实抗病性来延缓衰老并维持其品质。本研究为MT处理技术在火龙果低温贮藏保鲜中的深入研究及应用推广奠定基础。

火龙果产期调节技术研究综述

我国火龙果产业规模越来越大,但供应期集中制约了产业的高质量发展,而火龙果产期调节技术的实施可有效解决这一难题。文章从补光、修剪、疏花、喷施KH_(2)PO_(4)或植物生长调节剂等方面综述火龙果产期调节技术,为火龙果反季节生产提供技术参考,助力产业高质量发展。

茉莉酸甲酯调控白肉火龙果采后成熟的转录组分析

本研究以白肉火龙果(Hylocereus undatus)为材料,研究茉莉酸甲酯(MeJA)处理调控白肉火龙果采后成熟的机制。利用高通量测序的数字基因表达谱(DEGs)技术,对MeJA处理16 d的白肉火龙果果实和对照组的样品进行差异基因表达谱分析。结果显示,MeJA处理导致15 596个基因差异表达,其中上调表达基因6135个,下调表达基因9461个。GO功能显著性富集分析表明,差异表达基因主要涉及细胞过程、生物调节、物质合成、催化活性、结合活性和转运活性等。KEGG基因通路富集分析发现,差异表达基因富集于多条代谢通路上,主要涉及光合作用、植物激素信号转导、蛋白质加工、淀粉和糖类代谢等代谢途径。进一步分析发现,MeJA处理导致多个参与乙烯信号途径和细胞壁代谢途径的基因表达量显著下调,如ERF、EIN、XTH、PG和PME家族成员等。上述结果表明,MeJA处理可能抑制了乙烯信号转导和细胞壁代谢过程,从而延缓白肉火龙果采后成熟,延长果实的贮藏时间。本研究结果将为热带特色水果采后保鲜技术的开发与应用奠定基础。

1个侵染贵州火龙果的仙人指X病毒新的分离物基因组序列分析

【目的】分离侵染贵州火龙果的仙人指X病毒(Schlumbergera virus X,SchVX)基因组全长序列,了解其系统进化和遗传变异,为开展贵州火龙果病毒检测和防控奠定基础。【方法】从前期开展的火龙果成熟茎全长转录组测序获得的转录本中筛选SchVX相关序列,开展开放读码框(Open reading frame,ORF)预测、序列注释、一致率计算和系统进化分析。【结果】获得SchVX贵州火龙果分离物基因组序列,命名为SchVX-GZpitaya,基因组全长为6616 bp,5′和3′非翻译区(Untranslated region,UTR)长度分别为85 bp和101 bp。SchVX-GZpitaya与目前已报道SchVX分离物的基因组序列一致率为77.8%~78.4%,与其他侵染火龙果的马铃薯X病毒属病毒序列一致率为70.3%~73.0%。SchVX-GZpitaya编码的RNA依赖RNA聚合酶(RNA-dependent RNA polymerase,RdRP)与K11、Palma-PE、nopal verdura 1和DSMZ PV-0083分离物的氨基酸序列一致率为87.4%~88.3%,外壳蛋白(Coat protein,CP)的氨基酸序列一致率为87.1%~91.6%。基于全基因组或CP蛋白氨基酸序列的系统进化分析表明,SchVX-GZpitaya与目前已报道SchVX分离物的亲缘关系较近,但形成单独的一类。【结论】SchVX-GZpitaya是SchVX来自贵州火龙果的1个新分离物,其基因组序列与目前已报道的各类SchVX存在较大差异。

A Preliminary Report on Evolution and Selection of Excellent Pink Flesh Pitaya Strains

[Objective] This study was conducted to breed excellent-quality high-yield lines of pink flesh pitaya. [Method] 156 seedling progenies of ＇Conghua Zhixing＇ pink flesh pitaya cultivar were cultivated. Then the growth character, the high yield character, the fruit economic traits and interior quality were analyzed and compared. [Results] The best one which was marked as 80-1 was selected by the comprehen- sive quality. [Conclusion] It has attractive fruit surface, high quality and high yield.

Extraction Optimization of Polysaccharides from Pitaya Stems

[Objective]The aim was to describe the extraction of polysaccharides from pitaya stems.[Method]The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.[Result]The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:time >microwave power >temperature;additionally,optimal conditions included a 10 min extraction time,an 80℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.[Conclusion]The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.

Absence of Fruit Mexican Fly (<i>Anastrepha ludens</i>) in Pitaya de Mayo (<i>Stenocereus pruinosus</i>)

Pitaya de mayo (Stenocereus pruinosus) exportation is considered feasible especially to the United States of America (USA) using the adequate preservation and transportation techniques. One of the exportation requirements is that pitayas, as well as any other tropical fruits, have to be free from Mexican fruit fly contamination and certified by the Food National Sanitary, Iniquity, and Quality Service. This review proved that this fruit is not attacked by the Mexican fruit fly A. ludens or any other Anastrepha species. The fruit fly may be found in some States of Mexican Republic such as some tropical regions but not in the semi-arid regions where cacti fruits are grown.

Standardized Production Technology of Selenium-enriched Hylocereus undatus(pitaya) in Natural Selenium-rich Areas

With the adjustment of the tropical and subtropical fruit industry organizations in southern China, the Hylocereus undatus(pitaya) industry is growing rapidly in subtropical Guangxi and other places. Guangxi is also the largest natural selenium-rich region in the country, and selenium-enriched pitaya is increasingly sought after by the general public. This paper described in detail the selection of selenium-enriched pitaya production fields, key planting techniques and core selenium enrichment techniques, with a view to providing technical guidance for the standardized production of selenium-enriched pitaya and providing technical support for improving the quality and efficiency of pitaya production in natural selenium-rich areas.

Design and Realization of Image Database of Pitaya Disease

With the expansion of cultivation scale,pitaya diseases are gradually increasing.Traditionally relying on human observation to judge the disease is limited by the skills and experience of the observer,which cannot guarantee the accuracy and real-time of the judgment,and consumes much manpower and time.In this study,by collecting,segmenting,and labeling images of 4 main diseases of pitaya in the field,an image database of main diseases of pitaya in the field was constructed to provide a basis for computer image recognition of pitaya diseases.Thereby,it benefits reducing manual error and improving the accuracy and real-time of disease identification for agricultural production,but also lays a foundation for the future development of intelligent agriculture.

Alginate Encapsulation as a Preservation Method of Pitaya Fruit Juice （Stenocereus spp.）

Alginate is a widely used polymer matrix in food industry since it allows formation of spherical, soft, and strong membranes adequate for encapsulation of a large amount of products, including food. The flow rate of alginate solutions and the permeability of the capsules were evaluated within an acidic-low acidic pH range and different alginate concentrations. In solutions adjusted at different pH （3.0 to 7.0） with concentrations of alginate of 0.8, 1.0, and 1.2% w/v, flow rates at 20 ℃ were 6.95 to 10.00, 4.54-5.35, and 2.60-2.80 mL sl, respectively. Permeability of the capsules was evaluated in terms of the diffusion of H＋ions （expressed as pH） and soluble solids （~Brix）. Meanwhile both diffusions were minor at 4.0 〈 pH 〈 7.0 and were significantly superior at more acidic pH （P 〈 0.05）, alginate concentration did not present significant effect. Yellow, purple, and red juices from Stenocereus spp. fruits （pitayas） were encapsulated using 1.0% of alginate and stored with isotonic solution （3 mL g^-1） at 4 ℃ in the dark. The capsules were spherical with diameter between 4.59 and 470 mm, weight from 82.60 to 97.50 rag, and volume of 0.075-0.098 mL. Pigment （total betalains content） diffusion reached equilibrium at 24 h of storage, at which point retentions of total betalains in the yellow, purple, and red capsules were 87.79, 96.13, and 85.13%, respectively. Also, changes in the color of the capsules were observed during storage.

外源褪黑素处理对采后火龙果贮藏品质和活性氧清除能力的影响

为研究外源褪黑素(melatonin,MT)处理对采后火龙果的保鲜效果,以不同浓度(0.05、0.10和0.50 mmol/L)MT处理采后火龙果果实,并测定其贮藏品质和活性氧清除能力。结果表明:外源MT处理的保鲜效果与其浓度有关,相较于0.05 mmol/L和0.50 mmol/L,0.10 mmol/L MT处理能显著地抑制果实鳞片黄化,降低失重率,延缓总可溶性固形物和可滴定酸含量的下降,降低腐烂率。0.10 mmol/L MT处理还显著地提高了过氧化氢酶、过氧化物酶和抗坏血酸过氧化物酶活性及总抗氧化能力,增强对DPPH·和超氧阴离子自由基的清除能力。以上结果表明MT处理通过提高抗氧化酶活性及时清除衰老过程中产生的活性氧,缓解活性氧对采后火龙果造成的氧化损伤。

基于田间表型性状的火龙果优异种质资源评价研究

为了科学确定火龙果优异种质资源评价标准,以农业农村部南宁火龙果种质资源圃内保存的种质资源为试材,从植物学特征、开花结果特性、果实品质性状、抗性等方面比较分析及综合评价。结果表明,筛选确定18项优良、特异种质资源评价性状,其中优良种质的性状包括生长势、柱头与花药相对位置、单果质量、果肉质地、果肉风味、可溶性固形物含量、开花结果批次、着果率、商品果率、产量、溃疡病抗性、抗寒性、抗热性共13项,特异种质的性状包括花瓣颜色、茎蔓上刺量、果皮颜色、果肉颜色、单果质量、可溶性固形物含量、开花结果批次、产量、溃疡病抗性共9项。筛选出丰产性高的种质69份,大果种质5份,高糖度种质22份,果皮颜色优异的种质5份,果肉颜色特异的种质14份,无草腥味且风味较好的白肉种质4份,高抗溃疡病种质1份。

火龙果皮花青素生物转化菌株筛选及工艺优化

该研究以火龙果皮粉为发酵基质,采用20种食用真菌进行发酵,通过监测发酵后发酵液中花青素含量的变化,筛选出转化效率高的供试菌株作为火龙果皮发酵菌株,并采用响应面法优化其发酵工艺。结果表明,20种食用真菌中,经蜜环菌(Armillaria mellea)发酵的火龙果皮液中花青素含量最高,其最优发酵工艺为发酵时间5 d、接种量6%、发酵温度25℃、料液比1∶50(g∶mL)。在此优化条件下,发酵液中花青素含量达(2.03±0.02)mg/100 mL,是未经食用真菌转化的11.94倍,表明微生物辅助可有效转化火龙果果皮中花青素。

7种药剂对火龙果溃疡病田间防治药效试验

通过大田试验研究了锐收果香(400 g/L氯氟醚·吡唑酯悬浮剂)、健达(42.4%唑醚·氟酰胺悬浮剂)、碧翠(16%二氰·吡唑醚水分散粒剂)、善常(35%苯甲-吡唑酯悬浮剂)、阿米妙收(325 g/L苯甲·嘧菌酯悬浮剂)、露娜森(43%氟吡菌酰胺·肟菌酯悬浮剂)、拿敌稳(75%肟菌脂·戊唑醇水分散粒剂)7种药剂不同剂量对火龙果溃疡病(Neoscytalidium dimidiatum)的防治效果及其对火龙果产量的影响。研究结果表明:分别以有效成分锐收果香270 g/hm^(2)、健达360 g/hm^(2)、碧翠360 g/hm^(2)、善常270 g/hm^(2)、阿米妙收292.5 g/hm^(2)、露娜森193.5 g/hm^(2)、拿敌稳225 g/hm^(2),在火龙果生长旺盛期、溃疡病发生初期(开花初期),对火龙果茎叶全株喷药3次,每隔10 d 1次,7种药剂不同剂量在第3次药后14 d防效都在64%以上;其中,健达360 g/hm^(2)、阿米妙收292.5 g/hm^(2)、露娜森193.5 g/hm^(2)、拿敌稳225 g/hm^(2)防治效果超过80%,经过田间测产,健达360 g/hm^(2)、阿米妙收292.5 g/hm^(2)、露娜森193.5 g/hm^(2)、拿敌稳225 g/hm^(2)处理产量在7个处理中较高,4个处理的增产率均超过10%,综合整个试验的分析和观察,健达360 g/hm^(2)、阿米妙收292.5 g/hm^(2)、露娜森193.5 g/hm^(2)、拿敌稳225 g/hm^(2)4个处理,对火龙果溃疡病的防治效果最好。

不同栽植密度对火龙果果实产量、品质及病虫害发生的影响

【目的】探讨不同栽植密度对火龙果果实产量、品质及病虫害发生的影响,为火龙果合理密植提供理论依据。【方法】以‘大红1号’火龙果为试材,设置不同栽植密度进行处理,对火龙果果实产量、品质及病虫害发生的影响进行研究,将试验所得的综合数据进行统计分析。【结果】不同栽植密度的‘大红1号’火龙果产量差异显著,处理3(18000株/ha)的4a生火龙果产量显著高于其他处理,果实品质、病虫害发生程度与处理1(6000株/ha)、处理2(12000株/ha)差异不显著。处理4(24000株/ha)在第2 a提前进入盛果期;同一栽植密度,随着栽培年限的增加,火龙果产量也随之增加,当栽植密度为24000株/ha时,产量则呈现先增后降现象。【结论】18000株/ha处理的火龙果产量最高,果实品质较优,病虫害发生程度低,为最适宜栽植密度。