Hi,
Are you aware of chimeras with different ploidy levels in different layers and those having distinct genetic differences for many characters? I am aware of the Pinot series in grape and some tomato examples but I am interested to know if these can be routinely produced artificially or they are one off events.
Thanks
Ranjith
I am no expert on their production, but I know that there are many thornless raspberry and blackberry (Rubus) varieties that are periclinal chimeras. I am not sure of their ploidy. There is literature on these from at least as far back as the 1980's that may hold some of the answers you seek. Good Luck!
Many chemically induced polyploids vary in ploidy level in the different layers within an individual specimen, I do not have the paper or citation information currently but there was one study in which a chimera was produced through coculture of cells from a variagated Nicotiana and a second non variagated Nicotiana of a different species. If I remember correctly it was done via in vitro culture and the co-cultured cells were induced to produce adventitious shoots. It was a number of years ago so I might have some of the details wrong
Few papers report the purposeful attempts to synthesize periclinal chimeras and most experiments have been done on species in the Solanaceae using in vitro techniques (1). Graft hybridization followed by the developmental formation of graft chimera has been the earliest way in which new heritable changes have been induced and new varieties of crop plants have been obtained (2). Colchicine has been widely used to induce cytochimeras in fruiting plants where the cells of the outermost layer (LI) have a different ploidy level than the tunica layer (LII) and the corpus (LIII). Fruit shape changes after grafting the round shaped cultivar, cv. “Mytilini Round” (scion) on the long shaped cultivar, cv. “Piperaki Long” (rootstock), provided some hints on the molecular mechanisms that probably underly graft-induced changes (3). Recent studies have documented that grafting enables exchanges of both RNA and DNA molecules between the grafting partners, thus providing a molecular basis for grafting-induced genetic variation (4). Citrus can be considered a model taxon where graft hybridization, in vitro techniques and colchicine treatments have been used to experimentally induce periclinal chimeras and study their formation mechanisms (5, 6, 7). In Citrus it has also been proposed an efficient methodology for the routinely production of synthetic periclinal chimera (see abstract and the figures of the method at the active links 8 and 9 in the enclosed file). Hope these information could be of some help with your enquiry.
Dr. Ranney's reply also brought to mind the work of Contreras et al. I believe he gave a presentation regarding the difference in ploidy level within the tissues of (an ornamental conifer, the exact species I cant recall). It might have been a Ph.D. defense, a search of Contreras AND oryzalin would probably bring it up.
I'm not sure if this question is still active (since it was asked in 2014) but I'm currently working on it.
There is one nice review on this subject and wen it comes on synthesis of inter specific and even inter varietal chimeras it is everything but routine job.
https://www.researchgate.net/publication/304780007_Plant_Chimeras_the_good_the_bad_and_the'Bizzaria'
Article Plant Chimeras: the good, the bad, and the'Bizzaria’
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