‘荸荠’ב东魁’杨梅杂交群体构建与SSR杂种鉴定

Construction of a crossing population between two Chinese bayberry cultivars‘Biqi'and‘Dongkui'and hybrid identification by polymorphic SSRs

【目的】杨梅一般为雌雄异株,风媒传粉。现有栽培品种都来源于优良雌株的无性系。为探索杨梅栽培品种间杂交育种的技术途径。【方法】以著名的杨梅品种‘荸荠’为母本,‘东魁’雌株上偶尔出现的雄花为父本,这2个品种在遗传和果实表型上差异较大,通过人工套袋授粉获得杂交实生苗。然后用8个在父母本上表现多态性的SSR标记进行杂种鉴定。【结果】成功获得杂交实生苗117株,经过SSR分子鉴定,其中83个同时拥有父母本来源的特征片段,为真杂种,其余34株的母本为‘荸荠’,父本混杂。根据共显性SSR标记在F1代中的分离类型,对8个标记同一位点上不同等位基因的分离比例进行χ2检验,发现6个SSR位点符合孟德尔分离定律,2个出现偏分离现象。双亲和83个真正杂种后代的遗传聚类分析可分为2组:一组包含39个后代,与‘东魁’聚在一起;另一组包含44个后代,与‘荸荠’聚到一起。【结论】应用杨梅雌性栽培品种偶尔出现的雄花粉可以实现栽培品种间的杂交育种,SSR标记可以有效鉴别真杂种。获得的杂交群体可用于构建杨梅连锁图谱,对现代杨梅分子遗传学研究和杂交育种具有重要意义。

【Objective】Chinese bayberry is generally dioecious,wind-pollinated fruits. Current cultivarsare exclusively from the female plants selection and grating propagation. This research explores the possi-bility of a controlled crossing between commercial Chinese bayberry cultivars.【Methods】We selected‘Biqi＇cultivar as female parent for bagging,and accidental male pollens collected from cultivar‘Dong-kui＇,which is usually female,to do the crossing. Both parental cultivars are famous in Zhejiang Provincewith distinct genetic background and fruit phenotype. The offspring were tested with 8 polymorphic simplesequence repeat（SSR） markers to identify real hybrid.【Results】A total of 117 F1 seedlings were ob-tained,88 were identified as true hybrids with typical markers from both parents,33 seedlings are out-cross with unknown male source. Chi-square test showed that six of eight SSR markers were in accor-dance with the Mendel＇s law of segregation,whereas other two exhibited using unusual pollen from Chi-nese bayberry cultivar（female） and SSR molecular markers are efficient to distorted segregation.【Conclusion】It is possible to construct breeding population and identify the true hybrids. This population is suit-able to construct linkage maps.