梅花新品种‘治章骨红重翠’跨品种群特性机制探究

Exploration of cross-cultivar group characteristics of a new cultivar of Prunus mume ‘Zhizhang Guhong Chongcui’

摘要:

‘治章骨红重翠’梅是一个具有跨品种群特性的梅花新品种，它同时具有朱砂和绿萼品种群的典型特征，其萼绿、花白、木质部淡暗紫色，但其机制并不清楚。本研究对‘治章骨红重翠’梅、‘豫西朱砂’梅、‘豫西变绿萼’梅表型、花色苷含量和花青素合成通路相关基因的表达量进行测定，结果表明，花瓣、萼片和枝内新生木质部的红色程度与总花色苷含量呈正相关。MYBɑ1、MYB1、bHLH3是影响这3个品种花部与木质部呈现红色的关键转录因子基因，转录因子促进结构基因F3′H、DFR、ANS和UFGT高表达，从而促进红色性状的产生。综合分析后推测，‘治章骨红重翠’梅花瓣白色源于矢车菊合成通路上其他分支FLS、F3′5′H、LAR和ANR基因高表达，谷胱甘肽转移酶(glutathione transferase, GST)基因GST低表达；萼片绿色源于F3′H、DFR和ANS基因低表达；木质部红色源于ANS、UFGT基因高表达。本研究对‘治章骨红重翠’梅跨品种群特性作出初步解释，为梅花花色与木质部颜色的分子育种提供了参考。

Abstract:

‘Zhizhang Guhong Chongcui’ is a new cultivar of Prunus mume with cross-cultivar group characteristics. It has typical characteristics of cinnabar purple cultivar group and green calyx cultivar group. It has green calyx, white flower, and light purple xylem, but the mechanism remains unclear. In order to clarify the causes of its cross-cultivar group traits, the color phenotype, anthocyanin content and the expression levels of genes related to anthocyanin synthesis pathway of ‘Zhizhang Guhong Chongcui’, ‘Yuxi Zhusha’ and ‘Yuxi Bian Lü’e’ were determined. It was found that the red degree of petals, sepals and fresh xylem in branches was positively correlated with the total anthocyanin content. MYBɑ1, MYB1, and bHLH3 were the key transcription factor genes that affected the redness of the three cultivars of flowers and xylem. The transcription factors further promoted the high expression of structural genes F3'H, DFR, ANS and UFGT, thereby promoting the production of red traits. Combined with phenotype, anthocyanin content and qRT-PCR results, it was speculated that the white color of petals of ‘Zhizhang Guhong Chongcui’ were derived from the high expression of FLS, F3'5'H, LAR and ANR genes in other branches of cyanidin synthesis pathway, and the low expression of GST gene. The green color of sepals might be originated from the relatively low expression of F3'H, DFR and ANS genes. The red color of xylem might be derived from the high expression of ANS and UFGT genes. This study made a preliminary explanation for the characteristics of the cross-cultivar group of ‘Zhizhang Guhong Chongcui’, and provided a reference for molecular breeding of flower color and xylem color of Prunus mume.