Floral stages, ovule development, and ovule and fruit success in Iris tenax, focusing on var. gormanii, a taxon with low seed set

Ovule development and ovule and fruit success were investigated in Iris tenax var. tenax and I. tenax var. gormanii. Ovule development, including megasporogenesis and initial stages of megagametogenesis, occurred while flowers were still in bud. Final maturation of the seven-celled embryo sac occurred during the male phase of flowering. An earlier report that synergids persist after fertilization, and that nucellar nuclei migrate into the developing megagametophyte in I. tenax var. tenax, was not supported in the present study. Reproductive studies used two pollination treatments: outcrossing and selfing. Treatment results were compared with results from open pollination. Both varieties of I. tenax are self-compatible. Results showed that <5% of I. tenax var. gormanii ovules develop into seeds with open pollination, supporting earlier reports of low seed set. Hand pollinations improved reproductive success, suggesting that pollen may be limiting in nature.