小报春与岩生报春种间杂交亲和性研究

以报春花属报春花组的小报春(Primula forbesii)和指叶报春组的岩生报春(Primula saxatilis)为亲本,对种间杂交的结实性及花粉管行为进行了观察。结果表明:小报春与岩生报春种间杂交表现为不亲和,正反交组合正常结实率为0,但正交、反交组合花粉在柱头表面的萌发和花粉管伸长过程有明显差异,小报春花粉授粉4h后可以在岩生报春柱头表面萌发,但花粉管伸长的速度明显比对照组岩生报春(P)×岩生报春(T)、岩生报春(T)×岩生报春(P)]慢,并且花粉管生长弯曲,授粉192h后花粉管仍未到达子房;岩生报春的花粉可以在小报春柱头上正常萌发,授粉48h后花粉管到达子房;4个对照授粉组合均分别于24h(短花柱为母本)、48h(长花柱为母本)时完成受精过程。研究表明,岩生报春×小报春杂交存在受精前障碍,小报春×岩生报春杂交亲和性较好,并可通过幼胚拯救的方法获得组间杂种后代;花柱长度可能是影响种间杂交结实能力的因素之一。

Intergeneric Cross-compatibility between Primula forbesii (Section Monocarpicae) and Primula saxatilis (Section Cortusoides)

The cross-compatibility between Primula forbesii (Sect.Monocarpicae.Ex Pax ) and P.saxatilis (Sect.Cortusoides Balf.f.) was investigated by seed-setting and observation of pollen tube behavior after interspecific crosses.The results showed that no normal seeds were obtained from reciprocal crosses between the two Primula species.The pollens of P.forbesii were able to germinate at the stigma surface of P.saxatilis in 4 hours after pollination.However,pollen germination significantly lagged behind the control groups P.saxatilis (P)×P.saxatilis (T),P.saxatilis (T)×P.saxatilis (P)] and the pollen tube elongation was hindered so that the pollen tubes could not extend into the ovary in 192 hours after pollination.The pollens of P.saxatilis germinated successfully at the stigma surface of P.forbesii and the pollen tubes elongated into the ovary in 48 hours after pollination.The pre-fertilization barriers was observed in P.saxatilis×P.forbesii,while P.forbesii×P.saxatilis showed good interspecific compatibility,and the hybrid seedlings have been attained by embryo rescue.The length of stigmas may be one of the factors that influence the compatibility of interspecific hybridization.