Abstract: 【Objective】To better understand the cross-compatibility of double-petaled Hemerocallis and provide a reference and basis for breeding of more double-petaled Hemerocallis middendorfii varieties.【Methods】 The pollen germination rate was measured for the Hemerocallis varieties Burgundy 341,Baby′s Eyes and Lacy Doily grown in liquid culture. The benzidine-hydrogen peroxide method was used to determine the stigma acceptability. Using Burgundy 341 and Baby′s Eyes as the female parents,Lacy Doily as the male parent,and Lacy Doily as the female parent,Burgundy 341 and Baby′s Eyes as the male parent,four sets of cross combinations were prepared. F₁ generation′s morphological traits were noted,and cluster analysis was performed.【Results】Burgundy 341,with an average germination rate of 39.2%,had the highest pollen activity,while Lacy Doily had the lowest,with an average germination rate of 11.3%. All the three varieties had the highest stigma acceptability at 9：00 on the flowering day,the longest duration is Baby′s Eyes,according to the stigma acceptability test. For the crossing sets,Baby′s Eyes×Lacy Doily had the highest fruit setting rate. When Lacy Doily is used as female parent,the fruit setting rate was 0. The F₁ generation population was divided into two groups using cluster analysis. Seven materials in class Ⅰ with cup-shaped flowers with green eyes that were spotless on the outer perianth segments and ribbed white on the side. Ten materials in class Ⅱ that resembled the female parent Baby′s Eyes,which had long leaves,horn-shaped flowers,wrinkled perianth segment edges,and yellow on the side.【Conclusion】The phenotypic traits of the F₁ generation population exhibited good diversity and high ornamental value,making them suitable for garden landscaping and planting in Suqian of Jiangsu Province. Burgundy 341,Baby′s Eyes and Lacy Doily are all ideal parent materials.

Key words: Hemerocallis, Cross-compatibility, Pollen viability, Stigma acceptability, Phenotypic traits