Despite limited reported gene pool of C. arabica, biochemical variation of key
bioactive compounds is reported between traditional and modern Arabica cultivars.
Modern cultivars have greater contents of total lipids, kahweol, malic and
5-caffeoylquinic acids, and trigonelline. Based on these facts, the kahweol and the
kahweol/cafestol ratio could be used as a biomarker to differentiate between traditional and modern cultivars [67].
In Latin America, interspecific grafting is a common practice to prevent or reduce
the root injuries which started after the outcomes of following authors Raghuramulu
and Thimmaraju [68] who revealed that C. arabica is compatible to other coffee
accessions which was a breakthrough in diversifying the genetics of C. arabica via
using rootstock of other coffee varieties. The first reported work on the impact of
grafting on beverage quality was published by Melo et al. [69] in which he found no
caffeine difference between grafted and nongrafted plants. A comprehensive work in
this scenario was done by Bertrand et al. [70] whose outcomes described complete
compatibility of C. arabica (Caturra and Catimor) with C. robusta (T3446, T3718,
T3561, T3757, T3561) and low or no compatibility with C. liberica and C. dewevrei.
Rootstock and scion both found impacting, in one way or another, on viability,
growth, yield, and cup quality. The rootstock provided a good growth, mediocre
taped root system, high viability, strong stem, tallness but reduced yield. The drop in
yield may be seen in the more bumper vegetative growth and tall strong stems,
whereas low aluminum level in grafted plants may also a result of shallow root
system. On the other hand, scion affects the number of beans and bean size, albeit,
biochemical composition, and organoleptic qualities were found to be completely
unaffected [70]. Interspecific grafting has also been exploited as genetic tool to
produce decaffeinated or low caffeine coffee varieties. Caffeine is alkaloid stimulant
with its controversial effects on the central nervous system, e.g., insomnia. Owing to
debatable effects of caffeine on human health, the masses demand for the decaffeinated coffee hiked many times from last decade and currently decaffeinated coffee is
the 10% of world coffee consumption. All the market available decaffeinated coffee
has been produced by the artificial removal from the caffeinated coffee which is an
expensive process and it also deteriorates the coffee quality by disturbing the
biochemical composition of resulting decaffeinated coffee [71]. The limited genetic
pool of coffee varieties, especially for coffee Arabica, is the biggest bottleneck in
producing decaffeinated or low caffeine coffee varieties. However, the gene banks of
coffee are still expanding due to collection of huge wild genetic resources of coffee
plant across the Africa, Latin America, Madagascar, Indonesia, and Yemen by the
international missions and consortiums of coffee research [72]. This huge diversity
in genus Coffea reportedly have more than 21,000 accession worldwide now, and
some of these have been investigated for improving the adaptability, morphology,
yield, insect pest and disease resistance, and decaffeinated coffee production too [24,
38, 71, 73 ]. After the discovery of caffeine free (e.g., Coffea pseudozanguebariae)
or low caffeine coffee varieties (C. arabica; AD0591, AD2491), interspecific
grafting among different varieties was also performed, but rootstock was found
un-influential for the low or decaffeinated scions. According to statistical data of
Engelmann et al. [72] about the biodiversity of genus Coffea among the total
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
655
bioactive compounds is reported between traditional and modern Arabica cultivars.
Modern cultivars have greater contents of total lipids, kahweol, malic and
5-caffeoylquinic acids, and trigonelline. Based on these facts, the kahweol and the
kahweol/cafestol ratio could be used as a biomarker to differentiate between traditional and modern cultivars [67].
In Latin America, interspecific grafting is a common practice to prevent or reduce
the root injuries which started after the outcomes of following authors Raghuramulu
and Thimmaraju [68] who revealed that C. arabica is compatible to other coffee
accessions which was a breakthrough in diversifying the genetics of C. arabica via
using rootstock of other coffee varieties. The first reported work on the impact of
grafting on beverage quality was published by Melo et al. [69] in which he found no
caffeine difference between grafted and nongrafted plants. A comprehensive work in
this scenario was done by Bertrand et al. [70] whose outcomes described complete
compatibility of C. arabica (Caturra and Catimor) with C. robusta (T3446, T3718,
T3561, T3757, T3561) and low or no compatibility with C. liberica and C. dewevrei.
Rootstock and scion both found impacting, in one way or another, on viability,
growth, yield, and cup quality. The rootstock provided a good growth, mediocre
taped root system, high viability, strong stem, tallness but reduced yield. The drop in
yield may be seen in the more bumper vegetative growth and tall strong stems,
whereas low aluminum level in grafted plants may also a result of shallow root
system. On the other hand, scion affects the number of beans and bean size, albeit,
biochemical composition, and organoleptic qualities were found to be completely
unaffected [70]. Interspecific grafting has also been exploited as genetic tool to
produce decaffeinated or low caffeine coffee varieties. Caffeine is alkaloid stimulant
with its controversial effects on the central nervous system, e.g., insomnia. Owing to
debatable effects of caffeine on human health, the masses demand for the decaffeinated coffee hiked many times from last decade and currently decaffeinated coffee is
the 10% of world coffee consumption. All the market available decaffeinated coffee
has been produced by the artificial removal from the caffeinated coffee which is an
expensive process and it also deteriorates the coffee quality by disturbing the
biochemical composition of resulting decaffeinated coffee [71]. The limited genetic
pool of coffee varieties, especially for coffee Arabica, is the biggest bottleneck in
producing decaffeinated or low caffeine coffee varieties. However, the gene banks of
coffee are still expanding due to collection of huge wild genetic resources of coffee
plant across the Africa, Latin America, Madagascar, Indonesia, and Yemen by the
international missions and consortiums of coffee research [72]. This huge diversity
in genus Coffea reportedly have more than 21,000 accession worldwide now, and
some of these have been investigated for improving the adaptability, morphology,
yield, insect pest and disease resistance, and decaffeinated coffee production too [24,
38, 71, 73 ]. After the discovery of caffeine free (e.g., Coffea pseudozanguebariae)
or low caffeine coffee varieties (C. arabica; AD0591, AD2491), interspecific
grafting among different varieties was also performed, but rootstock was found
un-influential for the low or decaffeinated scions. According to statistical data of
Engelmann et al. [72] about the biodiversity of genus Coffea among the total
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
655