Abstract:
With selfing of
Magnolia sinostellata as a control, distant crosses of
M.sinostellata with
M.biondii, M.liliiflora, M.soulangeana ‘Red lucky’ and
M.soulangeana ‘Danxin’, respectively, were conducted to study the compatibility of selfing and that between species.
M.sinostellata had a relatively high pollen viability and stigma receptivity, and its pollen tube could go into the maternal style normally but had a selfing-based fruiting rate of 2%. The pollen from
M.sinostellata was fast identified by the stigma of
M.liliiflora and germinated at a higher percentage with a faster growing normal tube than by those of
M.soulangeana ‘Red lucky’ and
M.soulangeana ‘Danxin’.
M.liliiflora×M.sinostellata had a fruiting rate of 25% while the fruiting rate of
M.soulangeana ‘Red lucky’×
M.sinostellata and
M.‘Fragrant cloud’×
M.sinostellata was only 4% and 0, respectively. With
M.sinostellata as a maternal parent, the pollen of
M.biondii had a higher pollen germination rate than that of other three species, but the pollen tube twisted during growth and the callose was formed inside the style of
M.sinostellata, which resulted in no seed formation. All these indicated that pre-fertilization barriers, i.e. abnormal growth of pollen tube before reaching the bottom of the style, was the main reason for no fruiting in the cross of
M.sinostellata with either of
M.soulangeana ‘Danxin’ and
M.biondii. The abnormal state of pollen tube after entering into the ovary might lead to a low fruiting rate from selfing of
M.sinostellata and hybridization of
M.sinostellata with
M.liliiflora, or
M.soulangeana ‘Red lucky’.