The anti-ethylene growth regulator silver thiosulfate (STS) increases flower production and longevity in cassava (Manihot esculenta Crantz)

Cassava, which produces edible starchy roots, is an important staple food for hundreds of millions of people in the tropics. Breeding of cassava is hampered by its poor flower production, flower abortion, and lack of reproductive prolificacy. The current work determined that ethylene signalling affects floral development in cassava and that the anti-ethylene plant growth regulator silver thiosulfate (STS) mitigates the effects of ethylene on flower development. STS did not affect the timing of flower initiation, but improved early inflorescence and flower development as well as flower longevity such that flower numbers were increased. STS did not affect shoot and storage root growth. Studies of silver accumulation and treatment localization support the hypothesis that the beneficial effects of STS are confined to tissues of the shoot apex. The most effective timing of application was before inflorescence appearance extending to post-flower appearance. Based on this work a recommended protocol for STS use was developed. This work has the potential to improve methods for enhancing cassava flower development in breeding nurseries and thereby synchronize flowering of desired parents and enable the production of abundant progeny of desired crosses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10725-019-00542-x) contains supplementary material, which is available to authorized users.