Articles
EPIGENETIC EFFECTS IN INDUCED IN VITRO TETRAPLOIDS PASSION FRUIT (PASSIFLORA EDULIS SIMS.)
Article number
829_24
Pages
167 – 176
Language
English
Abstract
The passion fruit originates from southern Brazil through Paraguay to northern Argentina.
It has been stated that the yellow form is of unknown origin, or perhaps native to the Amazon region of Brazil.
The passion fruit is an important commercial fruit, and breeders have tried to combine its desirable commercial traits with the greater cold-hardiness of the maypop.
Hybrids are frequently sterile, although the sterility can be partly overcome by creating polyploid hybrids.
The present work related epigenetic effects to ectopic expression of carpels and ovules in passion fruit autotetraploid plants induced in vitro.
Autotetraploid plants induced with colchicine (25 mM) and oryzalin (5 mM) were regenerated in vitro and then transplanted and cultivated in a hydroponics system in a greenhouse.
Autotetraploids were more vigorous than the control diploid plants.
The chromosome number of diploid plants was 18 and that of tetraploid plants was 36. The stomata sizes of tetraploid plants were significantly larger than those of diploid plants, while the frequency of stomata were reduced significantly.
Similarly, the chloroplast number of guard cells of tetraploid plants increased significantly.
Beside this, the flowers of tetraploids showed epigenetic changes that resulted in phenotypes with a fringe like corona of straight, white-tipped rays, which were rich purple at the base.
These flowers formed more than five new ovaries, partially closed, each containing 20 ovules and on the end of their filaments, a structure like a style with a stigmatic surface emerged.
The results indicated that probably two Floral Binding Protein genes (FBP7 and FBP11) are involved in determination of ovule identity in Petunia and possibly also in passion fruit, but need more investigation.
It has been stated that the yellow form is of unknown origin, or perhaps native to the Amazon region of Brazil.
The passion fruit is an important commercial fruit, and breeders have tried to combine its desirable commercial traits with the greater cold-hardiness of the maypop.
Hybrids are frequently sterile, although the sterility can be partly overcome by creating polyploid hybrids.
The present work related epigenetic effects to ectopic expression of carpels and ovules in passion fruit autotetraploid plants induced in vitro.
Autotetraploid plants induced with colchicine (25 mM) and oryzalin (5 mM) were regenerated in vitro and then transplanted and cultivated in a hydroponics system in a greenhouse.
Autotetraploids were more vigorous than the control diploid plants.
The chromosome number of diploid plants was 18 and that of tetraploid plants was 36. The stomata sizes of tetraploid plants were significantly larger than those of diploid plants, while the frequency of stomata were reduced significantly.
Similarly, the chloroplast number of guard cells of tetraploid plants increased significantly.
Beside this, the flowers of tetraploids showed epigenetic changes that resulted in phenotypes with a fringe like corona of straight, white-tipped rays, which were rich purple at the base.
These flowers formed more than five new ovaries, partially closed, each containing 20 ovules and on the end of their filaments, a structure like a style with a stigmatic surface emerged.
The results indicated that probably two Floral Binding Protein genes (FBP7 and FBP11) are involved in determination of ovule identity in Petunia and possibly also in passion fruit, but need more investigation.
Authors
M.M. do Rêgo, E.R. do Rêgo, W.C. Otoni, C.H. Bruckner
Keywords
colchicine, in vitro culture, polyploids
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