梅与山桃远缘杂交亲和性初步研究

Study on Cross-compatibility between Prunus mume and P.davidiana

为培育早花抗寒梅花新品种,以梅(Prunus mume)品种‘江梅’(P.mume‘Jiangmei’)、‘淡丰后’(P.mume‘Dan Fenghou’)与山桃(P.davidiana)、‘白花’山桃(P.davidiana‘Alba’)为亲本进行杂交试验,记录种间杂交结实率,观察花粉管生长,对未成熟胚进行培养。结果表明:(1)梅与山桃、‘白花’山桃杂交结实率很低,‘江梅’ב白花’山桃未结果,结实率最高的组合为‘淡丰后’×山桃,也仅有7.4%,且杂交果实的果核内部分胚干瘪、败育。(2)山桃和‘白花’山桃的花粉在梅柱头上都能正常萌发,但花粉管生长受抑制,多数花粉管到达花柱中部即弯曲、缠绕、断裂,花粉管生长过程中有大量的胼胝质产生,表现较低的杂交亲和性,但不同种间杂交亲和程度又有所不同。(3)通过未成熟胚培养获得了杂种苗。研究表明,梅与同属种杂交存在不亲和性,幼胚拯救是获得梅与李属其他种远缘杂交杂种苗的有效途径。

To breed new Mei cultivars with cold-resistant and blossom early characteristics,we investigated the interspecific compatibility between Prunus mume and P.davidiana by observing fruit set and the pollen tube growth by means of fluorescence microscopy,and immature embryo culture.Results showed that：（1）The fruit set was quite low in all crosses,especially the cross of P.mume ‘Jiangmei＇×P.davidiana‘Alba＇failed to form fruits.The cross of P.mume‘Dan Fenghou＇×P.davidianaobtained the highest fruit set 7.4%,and part of fruits were abortive.（2）After cross-pollination,the pollinations of P.davidianaand P.davidiana ‘Alba＇could germinate normally on the stigma of P.mume,but the pollen tube growth was hindered along the style.A higher number of pollen tubes stopped growing when reaching the middle section of the style,and some bended,twined and fractured,but no pollen tubes were observed reaching the base of the style or growing down to the ovary.A large amount of callose accumulated in the process of pollen tube growth which showed the cross-incompatibility.There were differences between cross combinations.（3）Hybrid has been successfully obtained by culturing immature embryo,which indicates that embryo rescue techniques facilitate hybrid creation.