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.

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.

Genome-wide identification and characterization of the bHLH gene family in an ornamental woody plant Prunus mume

The basic helix-loop-helix(bHLH)transcription factor family is the second-largest family in plants,where it plays essential roles in development,and the responses to multiple abiotic and biotic stressors.However,little information is available about this gene family in Prunus mume,which is widely cultivated in East Asia as an ornamental fruit tree.Here,100 PmbHLH genes were identified,and their evolution and functions were explored in P.mume for the first time.The PmbHLH genes were classified into 21 subfamilies.The chromosomal distribution,physicochemical properties,bHLH domain,conserved motif,and intron/exon compositions were also analyzed.Furthermore,the evolutionary pattern,divergence time of the PmbHLH family,and genetic relationships among P.mume,Arabidopsis thaliana,and Prunus persica and Fragaria vesca of Rosaceae were explored.The functional prediction analysis of these PmbHLHs indicated that their functions varied,and included participating in the formation of organs and tissues,responding to stress,and the biosynthesis and metabolism of hormones and other secondary metabolites.Interestingly,expression analyses of PmbHLHs also revealed diverse expression patterns.Most of the PmbHLH genes were highly expressed in roots and stems,and a few were highly expressed in leaves,buds,and fruits,indicating tissue expression specificity.Eight PmbHLH genes,which were upregulated during low-temperature stress,may have critical roles in the response to cold stress.Ten PmbHLHs were differentially expressed between weeping and upright branches in a P.mume F_(1) population.These results shed light on the structure and evolution of the PmbHLH gene family,and lay a foundation for further functional studies of the bHLH genes.

The Use of Prunus mume in the Development of Low Chill Apricot Varieties:the Status of Work in the United States

Several groups in the USA have been working to de-velop a low chill apricot that would ripen its fruits veryearly in the season. Unfortunately, the cultivatcd apricothas been developed mainly from the high chilling Euro-pean group within the species Prunus armeniaca. Amongthe five groups within the apricot species, this is the mostrecently evolved and least variable (Bailey and

BULKED SEGREGANT RNA SEQUENCING(BSR-SEQ)IDENTIFIES A NOVEL ALLELE ASSOCIATED WITH WEEPING TRAITS IN PRUNUS MUME

Weeping species are used both as ornamental plants and for breeding dwarf plant types.However,exploration of casual genes controlling weeping traits is rather limited.Here,we identified individuals with contrasting phenotypes from an Fx bi-parental mapping population of Prunus mume which was developed from a cross between the upright cultivar/Liuban,and the weeping cultivar'Fentai Chuizhi'.Bulked segregant RNA sequencing was used and five QTLs on chromosome 7 were identified.The Pm024074(PmilGT72B3)allele,belonging to the UDP-glycosyltransferase superfamily containing the coniferyl-alcohol glucosyltransferase domain,was identified in a genomic region overlapping with a previously identified QTL;and had a synonymous transition of T66(upright)to C(weeping)in the coding sequence and a 470-bp deletion in the promoter region.Pm024074 had exceptionally high expression in buds and stems of weeping P.mume.Weighted correlation network analysis indicates that genes neighboring Pm024074 were significantly associated with plant architecture.In addition,a reliable single nucleotide polymorphism marker was developed based on the variation in the Pm024074 gene,providing precise marker-assisted breeding for weeping traits.This study provides insights into the genetic mechanism governing the weeping trait in P.mume,and indicates potential applications for the manipulation of tree architecture.

不同浓度的GA3处理在梅花促成栽培中的应用

梅花(Prunus mume Sieb.et Zucc.)具有很高的观赏价值和美好的寓意,而中国的春节正值每年的寒冬时节,可供人们观赏的花卉不多,因此植物工作者将梅花等部分早春开花的植物进行促成栽培,将其花期提前到春节前后,以满足人们的观赏需求,丰富人们的精神生活。近年来在梅花促成栽培的过程中因为有部分梅花所需的有效积温较高,在品种繁多的促成栽培过程中很难做到花期一致,因此在近几年的促成栽培过程中使用GA3处理,最终得出在GA3200 mg/L时能够在有效积温较低的情况下有效地打破休眠,达到提前开花。

梅花扦插繁殖研究进展

阐述了梅花(Prunus mume Sieb.)扦插繁殖中梅花树种的遗传差异、插穗生长程度、扦插繁殖时间的差异、基质选择以及不同类型植物生长调节剂对成活率的影响,讨论了种植后环境对扦插繁殖过程的影响,对扦插繁殖存在的问题提出了一些建议,旨在进一步促进梅花扦插繁殖的发展。