甘菊与栽培菊‘金陵黄玉’种间杂交失败的原因  

Investigation on the Factors Leading to Infertility in the Cross Between Dendranthema lavandulifolium and D. grandiflorum ‘Jinling Huangyu’

作　　者：孙春青[1] 陈发棣[1] 房伟民[1] 刘兆磊[1] 侯喜林[1] 滕年军[1] 

机构地区：[1]南京农业大学园艺学院,南京210095

出　　处：《园艺学报》2009年第9期1333-1338,共6页Acta Horticulturae Sinica

基　　金：中国博士后科学基金项目(20060400945);江苏省博士后科研计划项目(0602043B);教育部新世纪优秀人才支持计划项目(NCET-06-0489)

摘　　要：二倍体野菊与栽培菊种间杂交常不能结实,从而严重影响了野菊优异基因的利用,为了揭示其原因,以栽培菊(Dendranthema grandiflorum)‘金陵黄玉’为母本,二倍体野生菊甘菊(D.lavandulifolium)为父本,开展了种间杂交,测定了父本花粉活力,研究了授粉后花粉在柱头萌发行为及胚胎发育情况等。结果发现,父本甘菊的花粉活力在授粉时为11.2%,人工授粉4h内未观察到柱头上有花粉萌发;授粉后8h时平均每个柱头上只有7.5粒花粉萌发;到授粉后12h时数量达到最多,为16.1粒;随后数量急剧下降,到24和48h时柱头萌发花粉数量分别只有3.2粒和2.4粒,且大部分花粉管生长异常并停留在柱头表面。此外,在授粉8d后观察到12.0%子房中含有正常的球形胚,但之后就未观察到正常胚胎,最终未获得杂交种子,而母本自然开放结实率高达42.3%。以上结果表明,受精前、后的生殖障碍,即母本柱头上花粉萌发数量少且萌发异常和受精后胚胎大量败育,是引起种间杂交不结实的主要原因。Seeds are seldom obtained in the crosses between chrysanthemum cultivars and diploid wild species in Dendranthema, which seriously influences utilization of excellent genes from those wild speices. In the present study, with an aim to reveal the factors leading to infertility in the crosses between chrysanthemum cultivars and wild species, we carried out the interspecific hybridization between D. grartdiflorum ＇ Jinling Huangyu＇ and D. lavandulifolium, tested pollen viability of male parent, examined germination behavior of pollen grains on the stigmas after pollination, and observed embryo development. It was found that pollen viability of D. lavandulifolium was 11.2% just before pollination, no pollen grains germinated on the stigmas during 4 h after pollination and only 7.5 pollen grains germinated on each stigma at 8 h after pollination. At 12 h after pollination, the number reached the highest value, 16. 1. At 24 h and 48 h after pollination, the number was quickly decreased to 3.2 and 2.4, respectively. In addition, most pollen grains germinated abnormally on the stigmas and many pollen tubes stayed on the stigmas＇ surface and failed to enter ovaries. At 8 d after pollination, normal globular embryos were observed only in 12.0% ovaries. Thereafter, only abnormal embryos were observed in some ovaries, and as a consequence, no seeds were obtained in the cross. However, seed set of female parent under open pollination conditions was as high as 42. 3 %. These results suggest that both pre- and post-fertilization barriers, i. e. only a few germinated pollen grains on the stigmas and abnormal germination of most pollen grains before fertilization as well as degeneration of a large number of embryos after fertilization, may be the main factors resulting in infertility in the cross.

关 键 词：菊花 人工杂交 结实率 花粉活力 胚胎败育 

分 类 号：S682.11[农业科学—观赏园艺]