On the other hand, Robusta is a resistant variety, less susceptible to diseases, with a
higher content of caffeine and lower quality than Arabica. It is used in different
forms as soluble coffee, or a base for blends with Arabica coffee, and in the new
trend of espresso preparations to produce the cream on top of the beverage [58].
Three genotype group has been discovered in C. arabica, namely, wild type (SudanEthiopian origin), introgressed lines (from hybrid of timor), and nonintrogressed
lines (typica and bourbon), whereas C. robusta has been find with two genetic
classes known as Guinean group and Congolese group [59]. Table 2 represents the
different group of varieties for the C. arabica grown around the world in the coffee
producing countries. For C. robusta, most of its cultivars are still from unelected
open-pollinated seeds [60], while selection of its varieties from clones and hybrids
successfully achieved in past and still underway in many countries of Central and
Latin America, Africa, Indonesia, etc., with or without compromising the yield,
resistant against other insect, pest, and diseases [61]. Each coffee variety (both
Arabica and Robusta) is specified to a specific region with a set of its own inherent
quality characteristics which played an important role in the production of certified
specialty, organic, or other same kind of coffees. As each variety of coffee is destined
to a specific region or area, so the environmental, climatic, soil nutritional characteristics of that area offer a decisive role on composing the discreet profile of all
compounds which play an important part in making that variety peculiar from others
in terms of flavor, aroma, body, and taste as Steen et al. [62] described in his work
that coffee varieties nearly have more than 800 compounds, but actually flavor,
aromatic, or nonaromatic compounds are manifold of this figure, which may arise
due to complex nature interaction among these >800 compounds during the roasting
and brewing process. Nonetheless, literature still needs the data (or data available
only focus the C. arabica hybrids or hybrids of timor) about profiling of flavoring,
aromatic, or nonaromatic compounds among different group of varieties or with in
the same variety to find out the causes of their enjoying discrete status. The only
reason provided by the scientific reports on the variation of biochemical composition
among different coffee varieties is their variation in genetic traits [38]. The genetic
diversity of coffee varieties is the main constriction (especially for C. robusta) in the
choice of coffee variety with its inborn attributes [63]. But this genetic diversity is
also a boon for developing new varieties via hybridization with improved yield and
insect pest and disease resistance as populations with reduced genetic diversity are
more vulnerable to environment changes and thus lowering their chances of persistence [64]. In contrast, most of the C. arabica cultivars are derived from “typica” or
“bourbon” genetic sources which resulted in low genetic diversity among cultivated
arabicas [65]. So C. arabica plants are naturally vulnerable to various coffee diseases
such as coffee leaf rust (CLR) (H. vastatrix) coffee berry disease (CBD)
(Colletotrichum kahawae) and root-knot nematode (Meloidogyne spp.) [66]. But
several breeding and genetic improvement programs are proved to be very helpful by
diversifying the gene pool of C. arabica via interspecific hybridization with C.
robusta, C. liberica, and C. congensis, and now many CLR, CBD, and nematode
resistant varieties of C. arabica are under cultivation, but still the gene pool of coffee
is lacking the drought and cool tolerance, herbicide and borer resistance traits [65].
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
651
higher content of caffeine and lower quality than Arabica. It is used in different
forms as soluble coffee, or a base for blends with Arabica coffee, and in the new
trend of espresso preparations to produce the cream on top of the beverage [58].
Three genotype group has been discovered in C. arabica, namely, wild type (SudanEthiopian origin), introgressed lines (from hybrid of timor), and nonintrogressed
lines (typica and bourbon), whereas C. robusta has been find with two genetic
classes known as Guinean group and Congolese group [59]. Table 2 represents the
different group of varieties for the C. arabica grown around the world in the coffee
producing countries. For C. robusta, most of its cultivars are still from unelected
open-pollinated seeds [60], while selection of its varieties from clones and hybrids
successfully achieved in past and still underway in many countries of Central and
Latin America, Africa, Indonesia, etc., with or without compromising the yield,
resistant against other insect, pest, and diseases [61]. Each coffee variety (both
Arabica and Robusta) is specified to a specific region with a set of its own inherent
quality characteristics which played an important role in the production of certified
specialty, organic, or other same kind of coffees. As each variety of coffee is destined
to a specific region or area, so the environmental, climatic, soil nutritional characteristics of that area offer a decisive role on composing the discreet profile of all
compounds which play an important part in making that variety peculiar from others
in terms of flavor, aroma, body, and taste as Steen et al. [62] described in his work
that coffee varieties nearly have more than 800 compounds, but actually flavor,
aromatic, or nonaromatic compounds are manifold of this figure, which may arise
due to complex nature interaction among these >800 compounds during the roasting
and brewing process. Nonetheless, literature still needs the data (or data available
only focus the C. arabica hybrids or hybrids of timor) about profiling of flavoring,
aromatic, or nonaromatic compounds among different group of varieties or with in
the same variety to find out the causes of their enjoying discrete status. The only
reason provided by the scientific reports on the variation of biochemical composition
among different coffee varieties is their variation in genetic traits [38]. The genetic
diversity of coffee varieties is the main constriction (especially for C. robusta) in the
choice of coffee variety with its inborn attributes [63]. But this genetic diversity is
also a boon for developing new varieties via hybridization with improved yield and
insect pest and disease resistance as populations with reduced genetic diversity are
more vulnerable to environment changes and thus lowering their chances of persistence [64]. In contrast, most of the C. arabica cultivars are derived from “typica” or
“bourbon” genetic sources which resulted in low genetic diversity among cultivated
arabicas [65]. So C. arabica plants are naturally vulnerable to various coffee diseases
such as coffee leaf rust (CLR) (H. vastatrix) coffee berry disease (CBD)
(Colletotrichum kahawae) and root-knot nematode (Meloidogyne spp.) [66]. But
several breeding and genetic improvement programs are proved to be very helpful by
diversifying the gene pool of C. arabica via interspecific hybridization with C.
robusta, C. liberica, and C. congensis, and now many CLR, CBD, and nematode
resistant varieties of C. arabica are under cultivation, but still the gene pool of coffee
is lacking the drought and cool tolerance, herbicide and borer resistance traits [65].
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
651