关键词: 黄花菜, 花器官, 柱头, 可授性, 繁育系统, 杂交育种

Abstract:

The sexual propagation of Hemerocallis citrina‘Datong Huanghua’was determined by the flowering characteristics and breeding system. To promote the process of hybrid breeding,we investigated the flowing traits including the morphological characteristics of flowers,blooming process,pollen vitality changes under varied storage temperatures,stigma receptivity,breeding system types,and hybrid seed setting rate. The results showed that：（1）The flowering period of‘Datong Huanghua’started from mid-to-late June and ended at the end of July or early August. Flower buds at maturity show yellow-green color and turn bright yellow when opened;the florescence last about 12 hours. The pollen grains are oval with clear and deep net-like carvings on the outer wall.（2）With the extension of storage period,the pollen viability exhibited consistent decreasing trends at varied storage temperatures. During the 60-day storage period,the pollen viability was the highest under-80 ℃ storage condition among 25,4,-20 and-40 ℃.（3）After the petals opening,the stigma receptivity increased firstly and reached its maximum at 3 hours;then it started to decrease and lost the receptivity at 30 h.（4）The out crossing index（OCI）of‘Datong Huanghua’was 4 and the ratio of pollen and ovule（P/O）was 2 446.22. The fruit setting rate of natural cross-pollination was significantly higher than that of artificial self-pollination. Therefore,the breeding system of‘Datong Huanghua’is defined as facultative outcrossing type.（5）The multiple parental hybridization experiments revealed that the seed setting rate of‘Datong Huanghua’as male parent was higher than that of female parent.

Key words: Hemerocallis citrina, floral syndrome, stigma receptivity, beeding system, crossbreeding