Indirect somatic embryogenesis in Coffea with different ploidy levels: a revisiting and updating study

Autotetraploid Coffea canephora and Auto-Alloctaploid Coffea arabica From In Vitro Chromosome Set Doubling: New Germplasms for Coffea

“…This ISE pathway has been extensively exploited for Coffea plantlet regeneration since van Boxtel and Berthouly (1996). In addition, it was reproducible for different species and genotypes of the same species (Samson et al, 2006;Almeida et al, 2008;Ibrahim et al, 2015), such as the diploid C. canephora and C. eugenioides, allotriploid "Híbrido de Timor" "CIFC 4106" and true allotetraploid C. arabica (Sanglard et al, 2019). Therefore, the obtained new Coffea germplasms are a statement that van Boxtel and Berthouly's (1996) in vitro conditions are the base to establish tissue culture protocols for this genus.…”

“…These Coffea crops were chosen due to agronomic and evolutive relevance. C. canephora is a diploid species with 2n = 2x = 22 chromosomes and 2C nuclear DNA content of 1.43 pg, and C. arabica is a true allotetraploid that possesses 2n = 4x = 44 chromosomes and 2C = 2.62 pg (Sanglard et al, 2019). C. arabica is the only polyploid species of the Coffea genus, which was probably originated from crossing between the diploid species Coffea eugenioides S. Moore and C. canephora.…”

“…We collected and disinfected leaves of Coffea arabica according to Sanglard et al (2019) before inoculation. We excised five leaf fragments of 1cm² from both species and inoculated them in M1 medium (Table 1) in 60 × 15 mm Petri dishes.…”

“…Additionally, we evaluate the DNA sequence stability (SSR markers) and epigenetic (5-methylcytosine) level to find possible causes for the varying ISE responses. We choose C. canephora and C. arabica because of the previously established ISE for these species by our research group (Sanglard et al, 2019). Besides, C. canephora and C. arabica are relevant for the economy of some countries, like Brazil, Vietnam, Colombia, Mexico, Indonesia, India, Guatemala, Uganda, and Ethiopia.…”

Observations on Somatic Embryogenesis inCoffea arabicaL.

“…For the induction of callogenesis in Coffea genotypes in general it is used the protocol with MS medium [61] and the addition of phytoregulators 2,4 D and kinetin and 30 g/L sucrose [34]. At this stage, auxin 2,4 D is used at high concentration [26,[62][63][64][65] which causes disturbance of endogenous auxin metabolism of explant tissue leading to cell division [8]. Auxin stress is required to obtain calogenesis in most species [12,66].…”