Master of Science (MS)
Semester of Degree Completion
John M. Speer
Impatiens pallida Nutt. and Impatiens biflora Walt. are two closely related species which grow together in mixed populations but do not hybridize. Flower buds of each species were enclosed with glycine bags to prevent insect pollination. These were left isolated until after anthesis to test for self-pollination and self-compatibility. Neither capsule formation nor seed set were observed.
Chromosomal smears showed that each species has a haploid number of ten chromosomes. Polyploidy was not observed.
Field observations of insect pollinators (primarily bees) showed indiscriminate visitation.
Flower buds were again bagged as before. During anthesis, individuals of the two species were cross-pollinated utilizing a small brush. Neither capsules nor seeds developed.
A grindate was made from pistils of each species and placed on a 1.5% aqueous solution of agar adjusted to a pH of 7 with KOH. Although pollen would readily germinate on its own species’ grindate, it would not germinate on the grindate of the other species.
Buening, Sandra M., "Biosystematic Studies of Impatiens pallida and Impatiens biflora (Balsaminaceae)" (1979). Masters Theses. 3126.