Effect of temperature on inflorescence development and floral biology of mango (Mangifera indica L.).
Sukhvibul N., Hetherington S. E., Vithanage V., Whiley A. W., Smith M. K.
Author Affiliation: School of Land and Food, University of Queensland, St. Lucia 4072, Australia.
: 601-607
Abstract : Trees of 2 mono-embryonic (Irwin and Sensation) and 2 poly-embryonic (Nam Dok Mai and Kensington) mango cultivars were exposed to winter temperatures (21.6/9.5°C) to induce flowering. Plants were transferred into controlled environment glasshouse rooms under day/night temperature regimes of 15/5, 20/10, 25/15 and 30/20°C for 20 weeks. Inflorescence development only occurred on trees that were maintained at 20/10, 25/15 and 30/20°C. Higher temperatures generally increased inflorescence size while there was an inverse effect on the mean number of flowers per inflorescence with 619.6 at 20/10°C decreasing to 431.3 at 30/20°C. There was an inverse relationship between the length of anthesis period and temperature. Low temperatures of 20/10°C decreased the percentage of hermaphrodite flowers in poly-embryonic cultivars but increased the percentage in mono-embryonic cultivars. Style length and stigma width were reduced when trees were held at 20/10°C compared with those held at either 25/15 or 30/20°C. Kensington grown at 20/10°C mainly produced flowers which had short styles (0.62 mm) and small stigmatic surfaces. Nam Dok Mai and Irwin trees produced some flowers which had deformed ovaries or fused ovaries. Such developmental variations due to low temperatures (20/10°C) are likely factors contributing to low fruit set when grown in subtropical climates.