Delayed autonomous selfing in Kosteletzkya virginica (Malvaceae)

To test whether delayed autonomous selfing occurs in Kosteletzkya virginica, stylar movements, delayed autonomous selfing, corolla dragging, controlling pollination and autogamy rate were experimentally studied. The results indicated that delayed autonomous selfing and corolla dragging occur in K. virginica. Recurvature of stylar branches lasted until the stigmas touched or abutted on the anthers at the end of the anthesis day, only if stigmas did not received pollen from an external agent. However, recurvature stopped if stigmas received pollen from an external agent. Delayed autonomous selfing was due to direct stylar movements if stigmas touched with the anthers at the end of the anthesis day, or to the combination of corolla dragging with stylar movements if stigmas abutted on the anthers. The results of experimental hand pollinations indicated that K. virginica has a well-developed capacity for selfing, because the fruit set of natural and hand self-pollination were similar to hand cross-pollination. There were significant differences in the mean number of seeds per capsule for natural selfing, controlled selfing and controlled crossing (F2,57 = 234.877, P < 0.001). Field observations showed that over 4.00% of flowers undergo delayed autonomous selfing in the naturalised population of the study site and that this was closely related to weather conditions