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

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 breeding system of Hemerocallis hybridus cv.'Stella de oro'.The main results were that under artificial culture conditions,the population bloomed three or four times a year from May to September.The first flowering 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 acceptability 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 pollinator dependent.The special floral structure,lack of pollinators and short florescence might be the reasons that the species had a low setting percentage.