Evidence for a translocatable florigenic promoter in mango

Reproductive physiology of mango

“…Complete defoliation of girdled branches during inductive conditions results in vegetative shoots instead of generative shoots (Reece et al, 1949;Sen et al, 1972;Núñez-Eliséa andDavenport, 1989, 1992;Núñez-Eliséa et al, 1996). Davenport et al (2006a) recently confirmed this requirement of leaves for floral induction but also demonstrated that only ¼ leaf per stem provided sufficient FP to induce reproductive shoots in 95% of lateral shoots initiating in deblossomed 'Keitt' mango stems during cool, floral inductive conditions. In contrast, similar experiments recently conducted during warm temperature conditions in the Colombian tropics revealed that as many as four leaves per stem in 'Keitt' trees resulted in only 22% flowering of initiating lateral shoots (F. Ramirez and T.L.…”

“…Studies with mango have long supported the existence of a FP in mango leaves during exposure to cool, floral inductive temperatures (Reece et al, 1946(Reece et al, , 1949Singh, 1962Singh, , 1977Núñez-Eliséa andDavenport, 1989, 1992;Davenport and Núñez-Eliséa, 1990;Davenport et al, 1995). Complete defoliation of girdled branches during inductive conditions results in vegetative shoots instead of generative shoots (Reece et al, 1949;Sen et al, 1972;Núñez-Eliséa andDavenport, 1989, 1992;Núñez-Eliséa et al, 1996).…”

“…Reece et al (1946Reece et al ( , 1949 recognized that the fate of mango buds is not determined until their growth is initiated. Others have also noted that the vegetative or reproductive fate of resting apical or lateral mango buds is not predetermined at the time of shoot initiation (Mustard and Lynch, 1946;Núñez-Eliséa and Davenport, 1992;Davenport et al, 2006a). This characteristic differs from some temperate fruit trees in which previously initiated floral buds become dormant to over-winter before being evoked in the spring (Sedgley, 1990;Westwood, 1993;Greene, 1996).…”

“…Davenport et al (2006a) demonstrated that the amount of FP available from ½ leaf on a donor stem in cool conditions was sufficient to induce flowering in an average of 50% of shoots emerging on the donor stem and five leafless receiver stems inserted increasing distances along isolated 'Keitt' mango branches. The average maximum distance traveled by the FP from the donor stem to receivers was more than 100 cm.…”

“…The same cuttings initiated only vegetative shoots after that time . The measured time to deplete the active levels of FP in buds of isolated mango stems taken from trees exposed to cool floral inductive temperatures was 7 d after defoliation in warm (25°C night / 30°C day) conditions and 13 d in cool (10°C night / 18°C day) temperature conditions (Davenport et al, 2001;Davenport et al, unpublished). Thus, there is a constant turnover of the putative mango FP protein maintained by synthesis of new FP in leaves and deletion in buds.…”