M.H. Hagemann, P. Winterhagen, M. Hegele, J.N. Wünsche
Fruitlet abscission is a severe problem in mango (Mangifera indica) production; especially in the mountainous area of north Vietnam where hot and dry winds during long periods of drought cause severe premature fruit loss. Low rates of leaf net photosynthesis of averagely 8 µmol CO2/m2*s are typical for drought stressed mango trees. Presumably due to the declined carbon assimilation, fewer carbohydrates are available for fruit growth and development. Such stress can induce the fruit abscission process that involves an ethylene dependent signal cascade, including the examined ethylene receptors MiETR-1 and MiERS-1, sequence homologues to Arabidopsis ETR1 and ERS1, respectively. In the current study, ethephon spray applications on single clusters were used to induce artificially the abscission process in mango, leading to a rapid reduction of the fruit detachment force (FDF) and subsequent high rate of fruit drop. Both ethylene receptors showed a different expression pattern in the pedicel abscission zone in response to the ethephon treatment, whereas transcript levels in the untreated control remained unchanged. A high proportion (70%) of the variation in FDF of visually healthy appearing fruit in both treatments was explained by fruit length and pedicel diameter. The results clearly indicate, that the up-regulation of the examined ethylene receptors leads to a reduction of FDF and subsequently measured fruit drop.
Hagemann, M.H., Winterhagen, P., Hegele, M. and Wünsche, J.N. (2015). ETHEPHON INDUCED ABSCISSION OF MANGO FRUITLETS - PHYSIOLOGICAL FRUIT PEDICEL RESPONSE. Acta Hortic. 1066, 109-116
DOI: 10.17660/ActaHortic.2015.1066.11
Mangifera indica 'Hoi', fruitlet abscission, mango fruit drop, ethylene receptors, MiETR1, MiERS1, fruit detachment force

Acta Horticulturae