金樱子与2个现代月季品种杂交结实率差异的原因

以现代月季品种‘东方欲晓’和‘火焰舞’为母本,蔷薇属野生种二倍体金樱子(Rosa laevigata Michx.)为父本进行杂交,在人工杂交前,利用花粉离体培养法测定父本花粉活力,杂交后分别利用苯胺蓝染色法和常规石蜡切片技术研究授粉后花粉在柱头上萌发的形态特征以及胚胎发育情况。结果表明:杂交时金樱子花粉活力为39.8%;‘东方欲晓’与‘火焰舞’人工授粉后每个柱头上的花粉萌发数及萌发率均先升后降,在12 h达到最高值;但随后萌发数量急剧下降,并且大部分花粉管细短、弯曲且停留在柱头表面,到48 h时柱头萌发花粉数几乎为0。‘东方欲晓’在授粉后10 d可观察到其子房中幼胚异常降解,最终未收获到种子;‘火焰舞’的杂交胚胎中可观察到心形胚、鱼雷形胚及子叶形胚,但后期出现胚胎异常降解,结实率仅为6.3%。表明,父本花粉活力不影响杂交结实率,但授粉后24 h的花粉管出现异常以及受精后幼胚败育可能是导致‘东方欲晓’杂交失败的主要因素;胚胎后期败育是‘火焰舞’杂交结实率低的主要原因。

Factors affecting fruting rate in the crosses between Rosa laevigata Michx.and two rose cultivars

The artificial hybridization was carried out between diploid wild species Rosa laevigata Michx.and two rose cultivars:'Dongfangyuxiao'and'Huoyanwu',and pollen viability of male parent was tested,germination behavior of pollen grains on the stigmas after pollination was examined,and embryo development was observed.It was found that before the two rose varieties pollinating,the pollen viability of male parent was 39.8%.During the different time after pollination,average germinating pollen number and germinati...