Abstract: Iris scariosa is a perennial spring flowering Iridaceae species with important ornamental value. To explore the floral syndrome and breeding system and promote the utilization of this germplasm, flowering phenology, floral syndrome, breeding system and pollination traits of this species were studied in field and controlled experiments. The results were as follows:(1)I. scariosa began to flowering in early-May, peak flowering period was at mid-May, and final flowering period was at late-May, the duration of flowering was 16 d.(2)Its blue-purple flowers had scent and a small amount of nectar, and individual flower duration was 2.5-3.0 d.(3)Results of pollination experiments suggested that the breeding system of I. scariosa is obligate xenogamy, without apomixes and the ability of spontaneous self-pollination.(4)I. scariosa has a generalist pollination system, with Apis mellifera, A. cerana and Halictus sp. being pollinators. These insects initiated pollination while foraging for pollen, and their visitation frequencies were(0.57±0.05),(0.42±0.04)and(0.19±0.03)times·flower^-1·h^-1, respectively. Floral traits of this species, such as bright flower colors, large flower display, the peak of insect visitation overlapping with the period of highest pollen viability and the optimal stigma receptivity of pollen, yellow beard appendage on the outer tepals, etc., ensure the completion of the pollination process and enhance the successful outcrossing. This study provides an important theoretical information for the resource utilization and germplasm innovation of I. scariosa.

Key words: Iris scariosa, spring-flowering plant, floral syndrome, breeding system, outcrossing

摘要： 膜苞鸢尾(Iris scariosa)为鸢尾科鸢尾属的多年生春季开花植物,具有重要的观赏价值。为了探究该物种的花部综合征和繁育系统特性,促进其杂交选育和种质资源挖掘利用,该研究以膜苞鸢尾为研究材料,采用野外观测和控性实验相结合的方法,对其开花物候、花部综合征、繁育系统及传粉特性等方面进行了研究。结果表明:(1)该物种于5月初进入始花期,5月中旬进入盛花期,5月下旬进入末花期,开花持续时间为16 d。(2)花为蓝紫色,具有特殊气味和少量花蜜,单花花期为2.5～3.0 d。(3)人工授粉实验结果表明,该物种属于专性异交的繁育系统,不存在无融合生殖和自主自交能力。(4)该物种属于泛化传粉系统,意大利蜜蜂、中华蜜蜂、隧蜂是主要传粉者,访花频率分别为(0.57±0.05)、(0.42±0.04)、(0.19±0.03)times·flower^-1·h^-1。膜苞鸢尾花具有的艳丽颜色、较大的花展示、昆虫访花高峰期与花粉活力最高时期及柱头最佳授粉期相吻合,外花被片中脉上的黄色须毛状附属物等特征对保证其传粉过程的顺利完成并促进异交繁殖成功具有重要意义。该研究结果为膜苞鸢尾的资源利用与种质创新提供了重要的理论资料。

关键词: 膜苞鸢尾, 春季开花植物, 花部综合征, 繁育系统, 异交