大花萱草‘金娃娃’的花器结构和繁育系统观察

Studies on flower structure and breeding system of Hemerocallis hybridus cv.‘Stella de oro'

通过观察,运用杂交指数、花粉/胚珠、花粉及柱头活力、坐果率等指标对大花萱草‘金娃娃’(Hemerocallishybridus cv.‘Stella de oro’)的花部特征、开花动态及授粉特性等进行研究。在人工栽培条件下,金娃娃萱草5-9月开花,花苔分3～4次抽生,首次开花群体花期32d,单苔花期9～16d,单花花期1d。雄蕊短于花柱,花药与柱头相差2.71cm,在花朵开放的整个过程中雌、雄蕊的相对位置始终不变。开花前1d的花粉活力最强,开花前1d和开花当天的柱头具有较强的可授性。杂交指数为4,花粉/胚珠值为1 164,结合坐果率,可以判断其繁育系统属于兼性异交,部分自交亲和,需要传粉者。特殊的花部结构、缺少传粉者和花期短可能是金娃娃萱草结实率较低的原因。

A field investigation, including continuous observation, the use of outcrossing index, pollen and stigma viability; pollen-ovule ratio and fruit-set rate, was conducted on studing flower structure and breed-ing system of Hemerocallis hybridus cv. ‘ Stella de oro＇. The main results were that under artificial cul-ture conditions, the population bloomed three or four times a year from May to September. The first flow-ering span among populations was 32 days and for single scapes was 9-16 days. The life span of one single flower was 1 day. The stamen was close to the lateral side of the petaloid style and 2.71 cm shorter than the style. Relative position between the stamen and style was always unchangeable in the whole flowering process. The pollen viability was the strongest on the blooming day and the stigma had high stigma accept-ability on the blooming day and 1 day before blooming. The outcrossing index was 4 and P/O was about 1 164. Combined those with the result of the bagging and artificial pollination experiment, the breeding system of the species was given priority to facultative outcrossing, part self-compatibility and insect polli-nator dependent. The special floral structure, lack of pollinators and short florescence might be the rea-sons that the species had a low setting percentage.