Selection of Suitable Area and Analysis of Adaptability Difference of Prunus humilis

This paper delves into and assesses the differences in biological traits and fruit nutritional composition of 3 varieties of Prunus humilis introduced from 2 different regions.Results showed that(i)the contents of protein,total sugar,and calcium of No.5 variety were higher those of the other 2 varieties,which was recognized as the most suitable variety for fresh fruit;(ii)the comparison of leaf areas index and fruit shape index of 3 varieties shows that the fruit shape index and individual fruit weight of the introduced varieties were higher than those of the control,the diameter of individual fruit of the introduced varieties higher than that of the control indicated that they had a higher fruit hardness,more dry matter accumulation and better fruit quality,and that the introduction region was more suitable for scale-up of P.humilis;(iii)there was a positive correlation with the number of fruiting branches and there was a significant negative correlation with individual fruit weight,while the leaf area had a significant negative correlation with the number of fruiting branches.The introduced varieties can develop normally in the 2 testing areas,notably,No.5 variety performed better than No.4 and No.6.Improving management is the prerequisite for maintaining proper number of fruiting branches and high yield.

Molecular phylogeny and inflorescence evolution of Prunus(Rosaceae)based on RAD-seq and genome skimming analyses

Prunus is an economically important genus widely distributed in the temperate Northern Hemisphere.Previous studies on the genus using a variety of loci yielded conflicting phylogenetic hypotheses.Here,we generated nuclear reduced representation sequencing data and plastid genomes for 36 Prunus individuals and two outgroups.Both nuclear and plastome data recovered a well-resolved phylogeny.The species were divided into three main clades corresponding to their inflorescence types,-the racemose group,the solitary-flower group and the corymbose group-with the latter two sister to one another.Prunus was inferred to have diversified initially in the Late Cretaceous around 67.32 million years ago.The diversification of the three major clades began between the Paleocene and Miocene,suggesting that paleoclimatic events were an important driving force for Prunus diversification.Ancestral state reconstructions revealed that the most recent common ancestor of Prunus had racemose inflorescences,and the solitary-flower and corymb inflorescence types were derived by reduction of flower number and suppression of the rachis,respectively.We also tested the hybrid origin hypothesis of the racemose group proposed in previous studies.Prunus has undergone extensive hybridization events,although it is difficult to identify conclusively specific instances of hybridization when using SNP data,especially deep in the phylogeny.Our study provides well-resolved nuclear and plastid phylogenies of Prunus,reveals substantial cytonuclear discord at shallow scales,and sheds new light on inflorescence evolution in this economically important lineage.

Genome of tetraploid sour cherry (Prunus cerasus L.) ‘Montmorency’ identifies three distinct ancestral Prunus genomes

Sour cherry(Prunus cerasus L.)is a valuable fruit crop in the Rosaceae family and a hybrid between progenitors closely related to extant Prunus fruticosa(ground cherry)and Prunus avium(sweet cherry).Here we report a chromosome-scale genome assembly for sour cherry cultivar Montmorency,the predominant cultivar grown in the USA.We also generated a draft assembly of P.fruticosa to use alongside a published P.avium sequence for syntelog-based subgenome assignments for‘Montmorency’and provide compelling evidence P.fruticosa is also an allotetraploid.Using hierarchal k-mer clustering and phylogenomics,we show‘Montmorency’is trigenomic,containing two distinct subgenomes inherited from a P.fruticosa-like ancestor(A and A’)and two copies of the same subgenome inherited from a P.avium-like ancestor(BB).The genome composition of‘Montmorency’is AA’BB and little-to-no recombination has occurred between progenitor subgenomes(A/A’and B).In Prunus,two known classes of genes are important to breeding strategies:the self-incompatibility loci(S-alleles),which determine compatible crosses,successful fertilization,and fruit set,and the Dormancy Associated MADS-box genes(DAMs),which strongly affect dormancy transitions and flowering time.The S-alleles and DAMs in‘Montmorency’and P.fruticosa were manually annotated and support subgenome assignments.Lastly,the hybridization event‘Montmorency’is descended from was estimated to have occurred less than 1.61 million years ago,making sour cherry a relatively recent allotetraploid.The‘Montmorency’genome highlights the evolutionary complexity of the genus Prunus and will inform future breeding strategies for sour cherry,comparative genomics in the Rosaceae,and questions regarding neopolyploidy.

Chromosome-scale genome assembly of Prunus pusilliflora provides novel insights into genome evolution, disease resistance, and dormancy release in Cerasus L.

Prunus pusilliflora is a wild cherry germplasm resource distributed mainly in Southwest China.Despite its ornamental and economic value,a high-quality assembled P.pusilliflora genome is unavailable,hindering our understanding of its genetic background,population diversity,and evolutionary processes.Here,we de novo assembled a chromosome-scale P.pusilliflora genome using Oxford Nanopore,Illumina,and chromosome conformation capture sequencing.The assembled genome size was 309.62 Mb,with 76 scaffolds anchored to eight pseudochromosomes.We predicted 33035 protein-coding genes,functionally annotated 98.27%of them,and identified repetitive sequences covering 49.08%of the genome.We found that P.pusilliflora is closely related to Prunus serrulata and Prunus yedoensis,having diverged from them∼41.8 million years ago.A comparative genomic analysis revealed that P.pusilliflora has 643 expanded and 1128 contracted gene families.Furthermore,we found that P.pusilliflora is more resistant to Colletotrichum viniferum,Phytophthora capsici,and Pseudomonas syringae pv.tomato(Pst)DC3000 infections than cultivated Prunus avium.P.pusilliflora also has considerably more nucleotide-binding site-type resistance gene analogs than P.avium,which explains its stronger disease resistance.The cytochrome P450 and WRKY families of 263 and 61 proteins were divided into 42 and 8 subfamilies respectively in P.pusilliflora.Furthermore,81 MADS-box genes were identified in P.pusilliflora,accompanying expansions of the SVP and AGL15 subfamilies and loss of the TM3 subfamily.Our assembly of a high-quality P.pusilliflora genome will be valuable for further research on cherries and molecular breeding.

Post Debarking Response of Prunus africana (Hook. F) Kalkman (Rosaceae) Trees at Two Exploitation Sites in North Kivu (Eastern Democratic Republic of Congo)

Prunus africana is a species of great economic, medicinal and ecological importance. Due to its multiple uses, unsustainable exploitation methods and low regeneration capacity in tropical rainforests, this species is threatened with extinction. Present and exploited in the eastern part of DR Congo, knowledge of the dynamics of post-bark regeneration of Prunus africana remains fragmentary and poorly known. In North Kivu province, this species thrives in both afromontane forest and lowland tropical rainforest habitats. In order to contribute to the rational and sustainable exploitation of Prunus africana in this province, this paper was carried out with the objective of contributing to the knowledge of the dynamics of the regeneration of post-harvest bark of Prunus africana in two exploitation sites (low and high altitude). To achieve this objective, the inventory was conducted on 16 plots of 25 hectares each, with 8 plots per site. Dendrometric parameters (diameter at breast height (DBH), total tree height) and tree growth and regeneration parameters, i.e., stem bark thickness of the unharvested and harvested portions of the trees (bark reconstitution) were measured. A total of 716 barked stems of Prunus africana in 2016 in 25 hectares constituted the study sample. Results show that sites do not influence diameter at breast height of P. africana trees (p > 0.05) or total tree height. The bark diameter of harvested trees and the bark diameter of unharvested trees varied significantly by site (p 0.05). In contrast, the annual growth rate of bark differed with altitude;the highest rate was observed in trees growing at high altitude (2.97 ± 0.9 mm/yr) compared to 2.23 ± 0.74 mm/yr at low altitude. In view of these results, this study indicates that a half-rotation of 7 years could allow an effective reconstitution of the bark of Prunus africana at the second passage on the remaining side of the same stem.

桃(Prunus persica(L.) Batsch.)品种核心种质的构建与评价

为构建桃品种核心种质,通过对56份桃（Prunus persica（L.） Batsch.）初级核心种质的形态农艺性状数据（MOR）和SSR等位基因数据的分析,研究了不同聚类取样方法和完全随机取样方法下9种取样比例的遗传多样性指数、保留比例及各频率段等位基因的丢失比例。结果表明：聚类取样的方法优于完全随机取样,并以在80%的取样比例下MOR结合SSR数据聚类取样的效果最好,利用此方案构建的桃品种核心种质共包括45份材料,该核心种质的基因遗传多样性指数最高,保留了初级核心种质100%的形态农艺性状和96.6%的SSR等位基因,在出现频率低于0.05的等位基因中共丢失了2个等位变异,保留了出现频率在0.05-0.10的所有等位基因;利用6个数量性状对所构建的核心种质的代表性检测表明所构建的核心种质很好地代表558份桃原始种质的遗传变异。

普通杏(Prunus armeniaca)种质资源数量性状的遗传多样性分析

【目的】种质资源的遗传多样性研究是资源工作的核心，了解和掌握种质资源资源多样性，对于资源收集、管理、发掘、利用方面具有重要意义。【方法】对219份普通杏种质资源的11个性状进行了相关分析、主成分分析和聚类分析。【结果】普通杏种质资源各性状变异系数的变幅为15．7％。42．2％，其中可溶性固形物含量的变异系数最小，平均单果质量的变异系数最大。相关性分析得出：平均单果质量与叶柄长度、叶片长度和叶片宽度呈极显著正相关；可溶性固形物含量与可溶性糖呈极显著正相关：维生素C含量与可溶性固形物含量呈极显著正相关．与1a生枝粗度呈显著负相关。主成分分析结果表明：11个性状可以综合为4个主成分，前4个主成分累计贡献率达58．65％．第1主成分反映叶片因子，第2主成分反映枝条因子，第3、第4主成分反映的是品质因子。根据聚类分析把219份杏种质资源划分为6大类群：第1类种质群的主要特点是叶片较大：第Ⅱ类种质群的特点是果实品质性状较好．但是果实平均单果质量小；第Ⅲ类种质群的特点是果实平均单果质量大：第V类种质群的特点是果实品质好：第Ⅵ类种质群的特点是叶片较大且1a生枝又粗又长。【结论]普通杏种质资源的主要数量性状的变异较大，遗传多样性较丰富。

普通杏(Prunus armeniaca)初级核心种质资源的构建及评价

核心种质的构建不仅能够提高种质圃资源的保存效率、方便资源的管理,而且有利于种质资源的深入研究和种质创新。以国家果树种质熊岳李杏圃中保存的447份普通杏为材料,利用40个农艺性状的鉴定数据,对核心种质构建的几种聚类取样方案进行比较,明确了杏初级核心种质构建的最佳取样方案。在按品种类群分组的基础上,采用S策略经过多次聚类抽样,获得由111份种质材料组成的初级核心样本集,占总体样本比例25%。对该初级核心种质遗传多样性进行检测和评价,结果表明本研究所构建的初级核心种质能够很好地保留普通杏种质资源的遗传多样性。

基于优化LDSS法的中国李(Prunus salicina)初级核心种质构建

核心种质的构建不仅能够提高种质资源的保存效率、方便资源管理,而且有利于种质资源的深入研究和种质创新。以国家果树种质熊岳李杏圃中保存的405份中国李为材料,依据46个农艺性状的鉴定数据,在按品种类群和杂交类型分组的基础上采用S策略和优化后的最小距离逐步取样法(ILDSS)经2次抽样构建出中国李初级核心种质。该核心种质样本集由97份种质材料组成,占总体样本比例约24%。对核心种质群体的代表性进行检测,结果表明该核心种质群体能够代表中国李原种质资源的遗传多样性及其群体结构。平均多态位点百分率、平均Nei’s遗传多样性指数、平均Shannon-Weaver多样性指数、极差符合率、变异系数变化率、均值差异百分率、方差差异百分率和主成分分析(散点分布图)等8项指标能够有效地评价核心种质的遗传多样性和代表性。

防除杏树(Prunus armeniaca L.)冰核细菌药剂筛选及花期防霜效果

采用vali结冻法和含菌平板培养法，从9种供试药剂中筛选出1号、2号、3号、5号、7号5种对INA细菌触杀及破坏冰蛋白作用的药剂。将5种筛选的药剂于日光温室和田间进行药剂防霜试验研究，结果表明，日光温室霜冻温度为-4℃时，5种药剂中3号、7号防霜效果显著，分别为47．05％～67．74％和49．44％～69．33％。3号、7号分别提高座果率12．25％～14．83％和4．69％～11．36％，与对照相比差异达显著水平。大田温度为-6．5℃时，5种药剂中3号的防霜效果为21．80％，提高座果率9．17％。与对照相比达显著水平。

Genetic Relationships among Prunus mume var. pendula Using AFLP Markers

Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars of Prunus mume var. pendula were selected from the germplasm collection at the Research Center of China Mei Flower. Seven Mse I-EcoR I AFLP primer combinations revealed 450 legible bands, and 269 of which were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity and Neis (72) distance coefficient. A UPGMA dendrogram demonstrated the genetic relationships of the cultivars. The information given by AFLP markers was basically consistent with the morphological classification and the evolutionary history of the morphotypes, and roughly supported the new revised classification system for Chinese Mei Cultivars. But there were still several exceptions: 1) the Guhong Chuizhi inserted between the Tiaoxue Chuizhi and the Danfen Chuizhi; 2) the Wufu Chuizhi kept off the Pink Pendant Form, and the Moshan Chuizhi was removed from Viridiflora Pendant Form; 3) the Danbi Chuizhi and the Shuangbi Chuizhi of Viridiflora Pendant Form got together well but fell within the Pink Pendant Form.

Identification of Hybrids between Prunus salicina and Prunus armeniaca by RAPD and SSR

[ Objective] This study aimed to investigate the genetic variation between hybrids and their parents, and to find a rapid identification method. [ Method ] The progenies between Prunus armeniaca （ apricot ） Katy and Prunus salicina （plum） Moriteni were analyzed by means of RAPD and SSR molecular markers. [ Result] We found the differences in the electrophoresis bands between progenies and their parents, indicating that hybrid seedlings obtained in this study were real. [ Conclusion ] The combination of the above methods is effective and fast to identify the hybrids, and can shorten the breeding period.

桃(Prunus perscia)中一个AGAMOUS同源基因第二内含子序列的克隆和鉴定

研究首先从桃中克隆了AGAMOUS(AG)同源基因PpMADS4的第二个内含子——pPpMADS4,全长约2.1kb。序列分析表明,该内含子含有一些对基因表达十分重要的调控元件。同时,克隆了七个不同桃品种中的PpMADS4基因的第二内含子,序列比对和SNP测算表明,PpMADS4第二内含子是一段SNP富集区域,具有高度的核苷酸多态性,但是在这段序列上各个调控元件的序列和位置都非常保守,暗示了这些调控元件可能具有很重要的生物学功能。为了认识这一内含子的调控功能,将pPpMADS4与minimal35S连接并与GUS基因融合,构建表达载体转入野生型拟南芥中。GUS染色显示,其表达主要分布在花的两轮生殖器官上,这与拟南芥中AG第二内含子调控的GUS着色部位相似,但存在着差异。PpMADS4第二内含子能够特异启动GUS在花发育晚期的表达。

河南省南召县种植车厘子(Prunus avium L.)气候因子适宜性分析

利用年均温度、降雨量、日照时数、日照百分率和湿热指数等气候因子对河南省南召县种植车厘子的适宜性进行了分析研究.结果表明:南召县2011—2018年期间年平均气温(15.4℃)明显高于车厘子适宜的年均气温(10~12℃);年平均降雨量(743.7 mm)在车厘子生长发育对水分要求的适宜范围之内(600~800 mm);年均日照时数(1693.5 h)明显低于适宜的日照时数(2600~2800 h);1986—2002年的湿热指数与国内外车厘子主产区相比明显偏高.从大的气候范围来看,与国内外车厘子主产区相比,在南召县种植车厘子可能有树木生长旺盛、花芽形成不足、果实品质欠佳的风险.但充分利用东部浅山丘陵区等局部地区的小气候发展车厘子的种植是可行的.建议结合当地的温度、降雨量、日照时数和日照百分率等综合气候因子,选择合适的品种类型进行种植.

Molecular cloning,identification,and chromosomal localization of two MADS box genes in peach(Prunus persica)

MADS box proteins play an important role in floral development. To find genes involved in the floral transition of Prunus species, cDNAs for two MADS box genes, PpMADS1 and PpMADSIO, were cloned using degenerate primers and 5＇- and T-RACE based on the sequence database of P. persiea and P. duleis. The full length of PpMADS1 cDNA is 1,071 bp containing an open reading frame （ORF） of 717 bp and coding for a polypeptide of 238 amino acid residues. The full length of PpMADSIO cDNA is 937 bp containing an ORF of 633 bp and coding for a polypeptide of 210 amino acid residues. Sequence comparison revealed that PpMADS1 and PpMADSIO were highly homologous to genes API and PI in Arabidopsis, respectively. Phylogenetic analysis indicated that PpMADS1 belongs to the euAP1 clade of class A, and PpMADSIO is a member of GLO/PI clade of class B. RT-PCR analysis showed that PpMADS1 was expressed in sepal, petal, carpel, and fruit, which was slightly different from the expression pattern ofAPl; PpMADS10 was expressed in petal and stamen, which shared the same expression pattern as PI. Using selective mapping strategy, PpMADSI was assigned onto the Binl：50 on the G1 linkage group between the markers MCO44 and TSA2, and PpMADSIO onto the Bin1：73 on the same linkage group between the markers Lap- 1 and FGA8. Our results provided the basis for further dissection of the two MADS box gene function.

Accumulated chilling hours during endodormancy impact blooming and fruit shape development in peach(Prunus persica L.)

Winter chill is essential for the growth and development of deciduous species. To understand the relationship between accumulated chilling hours during endodormancy and blooming and fruit shape development, we controlled chilling hours and investigated their effects on blooming date and fruit shape of peaches. The results showed that the number of days to full bloom date and the heat requirement for blooming were negatively correlated with accumulated chilling hours. Accumulated chilling hours were significantly negatively correlated with fruit shape index and fruit tip lengths, suggesting that the number of chilling hours affect the fruit shape development. Fewer accumulated chilling hours may be the major reason for longer fruit shape and protruding fruit tips. In conclusion, our results indicate specifically that decreased winter chilling hours can delay the bloom date and may lead to aberrant fruit shape development in peaches. Our study provides preliminary insights into the response of temperate fruit species to global climate change.

Advanced hepatocellular carcinoma responds to MK615, a compound extract from the Japanese apricot “Prunus mume ”

MK615, a compound extracted from the Japanese apricot "Prunus mume " has been reported to have in vitro anti-tumor activities against several cancer cell lines,including hepatocellular carcinoma(HCC). However, the clinical effects and feasibility of administering MK615for patients with HCC were unknown. We experienced a case with advanced HCC for which MK615 was effective against both lymph node and pulmonary metastases. A 60-year-old female underwent surgical resection of a 9 cm HCC in the right lobe. The pathological diagnosis was moderately differentiated HCC with vascular invasion. The HCC recurred in the liver 8 mo after the surgery. Radiofrequency ablation and transarterial infusion chemotherapy were performed, but the recurrence was not controlled. One year after the intrahepatic recurrence, pulmonary and lymph metastasis appeared.Sorafenib was administered, but was not effective.Then, MK615 was administered as a final alternative therapy after informed consent was obtained from the patient. Three months later, her alpha-fetoprotein level decrease and both the lymph node and pulmonary metastases decreased in size. The patient has survived for more than 17 mo after the MK615 administration, and was in good condition. Although further investigations are necessary to clarify its safety and efficacy in humans, MK615 may be useful for the treatment of HCC,without serious adverse effects.

Genetic diversity,population structure,and relationships of apricot(Prunus)based on restriction site-associated DNA sequencing

Single-nucleotide polymorphisms(SNPs)are the most abundant form of genomic polymorphisms and are widely used in population genetics research.Here,high-throughput sequencing was used to examine the genome-level diversity,population structure,and relationships of apricot,which are important for germplasm conservation and molecular breeding.Restriction site-associated DNA sequencing(RAD-seq)was adopted to sequence 168 Prunus spp.accessions distributed in five ecological groups,including 74 accessions of cultivated Prunus armeniaca L.and 94 accessions of wild apricots(P.armeniaca L.and Prunus sibirica L.),which generated 417,961 high-quality SNPs.We used cluster,genetic structure,and principal component analyses to examine the genetic diversities and genetic relationships of the 168 accessions.The Dzhungar-Ili ecological group accessions showed the highest genetic diversity in terms of private allele number,observed heterozygosity,and nucleotide diversity.We speculate that the Central Asian ecological group accessions were domesticated from the Dzhungar-Ili ecological group accessions.The population structure and gene flow of the North China and European ecological group accessions suggested a genetic background of P.sibirica.We argue that the two groups should be considered hybrid swarms connected to P.sibirica by continuous and extensive gene flow.P.armeniaca originated in Northwest China(Ili Valley),subsequently spread throughout Central Asia,and eventually spread to Europe.In addition,selective sweep signatures in P.armeniaca during domestication from wild to cultivated apricots,combined with differentially expressed genes,underlie distinct fruit traits,including sugars,aromas,organic acids,and carotenoids.This study provides substantive and valuable genomic resources that will significantly advance apricot improvement and effective utilization.

Prunus genetics and applications after de novo genome sequencing:achievements and prospects

Prior to the availability of whole-genome sequences,our understanding of the structural and functional aspects of Prunus tree genomes was limited mostly to molecular genetic mapping of important traits and development of EST resources.With public release of the peach genome and others that followed,significant advances in our knowledge of Prunus genomes and the genetic underpinnings of important traits ensued.In this review,we highlight key achievements in Prunus genetics and breeding driven by the availability of these whole-genome sequences.Within the structural and evolutionary contexts,we summarize:(1)the current status of Prunus whole-genome sequences;(2)preliminary and ongoing work on the sequence structure and diversity of the genomes;(3)the analyses of Prunus genome evolution driven by natural and man-made selection;and(4)provide insight into haploblocking genomes as a means to define genome-scale patterns of evolution that can be leveraged for trait selection in pedigree-based Prunus tree breeding programs worldwide.Functionally,we summarize recent and ongoing work that leverages whole-genome sequences to identify and characterize genes controlling 22 agronomically important Prunus traits.These include phenology,fruit quality,allergens,disease resistance,tree architecture,and self-incompatibility.Translationally,we explore the application of sequence-based marker-assisted breeding technologies and other sequence-guided biotechnological approaches for Prunus crop improvement.Finally,we present the current status of publically available Prunus genomics and genetics data housed mainly in the Genome Database for Rosaceae(GDR)and its updated functionalities for future bioinformatics-based Prunus genetics and genomics inquiry.

Photoperiod-and temperature-mediated control of the ethylene response and winter dormancy induction in Prunus mume

Plant dormancy is essential for perennial plant survival.Different genotypes of Prunus mume,including Eumume group and Apricot Mei group,undergo leaf senescence and dormancy at different times.In order to verify the cold resistance of P.mume,freeze resistance evaluation was carried out.Our results showed that Apricot Mei group had a stronger freezing tolerance than Eumume group and that leaf senescence and dormancy of Apricot Mei group occurred at an earlier period before winter.Based on phenotypic data in response to seasonal climate change,the significant candidate regions were selected using GWAS.Furthermore,through KEGG pathway and qRT-PCR analyses,we found that the ethylene-related genes,including PmEIL(Pm002057)and PmERF(Pm004265),were significantly upregulated in‘Songchun’Mei(Apricot Mei group)and downregulated in‘Zaohua Lve’Mei(Eumume group).Ethylene-related genes expression models showed that ethylene may be indirectly involved in the induction of dormancy.The PmEIL and PmERF genes were the core genes of the ethylene signal transduction pathway and were regulated by the exogenous ACC or PZA compounds.For non-dormant or weekly dormant perennial plants,application of ACC was able to induce plant dormancy and thus enhance cold/freeze tolerance.Overall,the expression of the major ethylene genes played a significant role in dormancy induction and freezing tolerance in P.mume;accordingly,application of ACC and PZA compounds were an effective approach for enhancing cold/freeze of tolerance of woody plant.