Study on the effect of temperature and flower age on pollen performance, stigma receptivity and fruit-set of Moringa oleifera Lam.
Successful seed production is as a result of successful flower production, effective pollination, fertilization, fruit-set, growth, development and maturity of the fruit and seed. All these stages are affected by environmental factors as well as timing of certain events such as pollination and stigma receptivity. The effect of temperature on pollen performance, stigma receptivity and fruit-set were studied on moringa plants under Gauteng Province conditions at the Hatfield Experimental Farm, University of Pretoria, South Africa. Stigma receptivity starting from the day of and after anthesis was also studied to determine the optimum pollination, fertilization and fruit set period. Moringa flowers almost year round with some peak flowering periods in June and July (winter) and then in September to November (spring). In vitro pollen germination and tube growth were found not to be significantly different (p<0.05) at temperature ranging from 15 to 35°C at 5°C intervals. However, stigma receptivity increased with the increase in temperature. There were significant differences (p<0.05) in the number of pollen-tubes reaching the ovary and the number of ovules fertilized in the pistils from flowers that were exposed to the above temperature conditions. Stigmas were receptive from a day prior to anthesis to three days after anthesis, with the optimum receptivity on the day of anthesis after which it decreased with time. For optimum seed production and breeding purposes in Pretoria, Gauteng, crossings and pollination has to be carried out on the day of anthesis during the spring flowering.
Manduwa, D.M., du Toit, E.S. and Robbertse, P.J. (2018). Study on the effect of temperature and flower age on pollen performance, stigma receptivity and fruit-set of Moringa oleifera Lam.. Acta Hortic. 1204, 57-64
pollen germination, pollen-tube growth, anthesis, secretions, phenology