scholarly journals Assessment of coffee (coffea arabica L.) genetic erosion and genetic resources management in Ethiopia

2020 ◽  
Vol 7 (3) ◽  
pp. 223-229
Author(s):  
Afework Legesse

Coffee is an important source of annual income and employment contributing significantly to the economies of many developing countries. Ethiopia is the center of origin and diversity of Coffea arabica L., there is immense genetic variability that offers great potential for improvement of the crop. The objective of this paper is to assess the status of Coffee genetic diversity, identify major factors that cause coffee genetic erosion and status of coffee genetics resources management in Ethiopia.  The presences of high genetic diversity in wild Coffea arabica in Ethiopia were reported by different authors. However, the genetic diversity of coffea arabica L. are being lost rapidly due to several factors such as human population pressures leading to conversion of land to agriculture, deforestation and land degradation; low coffee prices leading to abandoning of coffee trees in forests and gardens and shifting cultivation to other more remunerative crops; and climate change. Additionally, narrow genetic basis of commercially used Arabica coffee cultivars and increased incidence of pests and diseases associated with climate change is leading to significant crop losses, threatening livelihoods in many coffee growing countries. Therefore, Conserving the wild Arabica coffee gene pool and its evolutionary potential present in Ethiopia is critically important for maintaining coffee yield, disease resistance, drought tolerant, quality and other important traits in future breeding program

Author(s):  
C. Montagnon ◽  
A. Mahyoub ◽  
W. Solano ◽  
F. Sheibani

AbstractWhilst it is established that almost all cultivated coffee (Coffea arabica L.) varieties originated in Yemen after some coffee seeds were introduced into Yemen from neighboring Ethiopia, the actual coffee genetic diversity in Yemen and its significance to the coffee world had never been explored. We observed five genetic clusters. The first cluster, which we named the Ethiopian-Only (EO) cluster, was made up exclusively of the Ethiopian accessions. This cluster was clearly separated from the Yemen and cultivated varieties clusters, hence confirming the genetic distance between wild Ethiopian accessions and coffee cultivated varieties around the world. The second cluster, which we named the SL-17 cluster, was a small cluster of cultivated worldwide varieties and included no Yemen samples. Two other clusters were made up of worldwide varieties and Yemen samples. We named these the Yemen Typica-Bourbon cluster and the Yemen SL-34 cluster. Finally, we observed one cluster that was unique to Yemen and was not related to any known cultivated varieties and not even to any known Ethiopian accession: we name this cluster the New-Yemen cluster. We discuss the consequences of these findings and their potential to pave the way for further comprehensive genetic improvement projects for the identification of major resilience/adaptation and cup quality genes that have been shaped through the domestication process of C. arabica.


Author(s):  
Rina Arimarsetiowati

One of the propagation technique for coffee plant production is tissue culture. Tissue culture technique for Coffea arabica L. faces some problems, mainly in the planlet formation regenerated from explants. The objective of this experiment was to examine the effect 2,4-D and 2-ip combination on the formation of direct somatic embryogenesis of Coffea arabica L. in leaves explant. Auxin (2,4-D) and cytokinin (2-ip) concentrations of, respectively, 1; 5 µM and 5; 10; 15; 20 were used as treatments. This research was conducted using completely randomized design with 10 replications. Observation to induce somatic embryos was done by quantitatively on number of callus from explant and number of embryogenic callus. Beside that, observation by qualitative descriptive was also done on deve lopment of embryogenesis. The results showed that Arabica coffee leaves explant of AS 2K clones could be induced in all medium combination except 5µM 2,4-D and 20µM 2-ip combination. Arabica coffee leaves explant of S 795, Sigararutang and AS 1 varieties could be induced in all medium combination. The highest frequency of callus formation was found in AS 2K, Sigararutang and AS 1 varieties on medium containing 1µM 2,4-D in combination with 10µM 2-ip, whereas for the S 795 variety on medium containing 5µM 2,4-D in combination with 10µM 2-ip. The highest frequency of embriogenic callus in all Arabica coffee variety could be reached on medium containing 5µM 2,4-D in combination with 15µM 2-ip. Key words : Coffea arabica L., somatic embryogenesis, 2,4-D, 2-ip, tissue culture, leaves, callus embryogenic.


2021 ◽  
Author(s):  
Kahiu Ngugi ◽  
Jane Jerono Cheserek ◽  
Chrispine Ogutu Omondi

Coffee as a cash crop, reduces food insecurity by providing regular incomes and is a major foreign exchange earner in more than fifty tropical countries where it is grown either as Arabica (Coffea arabica) or Robust (Coffea canepora). In Kenya which grow some Robusta but mostly Arabica coffee, the production has been declining, mainly because world coffee prices have plummeted to about 5 USD for a 650Kg of un-hulled beans per acre. The only way world prices are likely to increase and benefit the small-scale farmers, is by improving the cup quality and enabling these countries to sell their coffee in specialty markets. This review, underscores the importance of analyzing and estimating organoleptic, sensory and biochemical compounds diversity in Arabica coffee, since these are the factors that determine cup quality. In an attempt to do so, the chapter presents experimental data that analyzed various sensory and organoleptic traits of Arabica coffee and their Arabusta hybrids that proves that tremendous genetic diversity exists in coffee genotypes grown in Kenya and it is possible to utilize this genetic variation to improve cup quality.


2021 ◽  
Vol 3 (2) ◽  
pp. 25-31
Author(s):  
Reza Destri Anggi ◽  
Yuandani ◽  
Aminah Dalimunthe

The purpose of the research was to evaluate the teratogenic effect caused by theprovision of Arabica coffee solution with variations of 0.36 ml, 0.72 ml and 1.08 ml withpositive control of caffeine at a dose of 300 mg / kg bw to rats during organogenesis. Themeasurement parameters in this study are the appearance of reproduction, externalmalformations and scalal malformations. The results in this study found that theadministration of Arabica coffee solution with a volume of 1.08 ml and caffeine 300 mg /kg bb caused an abnormality in the reproductive appearance of weight loss and body length,whereas for extrenal malformation and scalal malforation no abnormalities were found ineach administration of the solution Arabica coffee and caffeine.  


2019 ◽  
Vol 1402 ◽  
pp. 055092
Author(s):  
R Handayani ◽  
N Auliasari ◽  
T K Oktaviany ◽  
S Hindun ◽  
F F Sriarumtias

1992 ◽  
Vol 32 (3) ◽  
pp. 401 ◽  
Author(s):  
EC Winston ◽  
M Hoult ◽  
CJ Howitt ◽  
RK Shepherd

The effects of ethephon on arabica coffee (Coffea arabica L.) were tested in experiments conducted over 2 years in North Queensland. Rates tested were 0, 125, 250, 500, 750, 1000, 1500, and 2000 mgkg, applied when 15-20% (early treatment) or 45-50% (late treatment) of fruit were coloured. Measurements were made on the degree of leaf and fruit abscission, berry ripening, and berry weight. Ethephon did not cause significant fruit abscission, but rates >500 mg/kg caused unacceptable leaf abscission. Rates of 250 mg/kg were marginally acceptable in terms of leaf abscission. Excessive defoliation led to dieback, which resulted in a reduced crop the following season. Ethephon concentrated berry ripening, significantly increased the number of red (mature) berries, and decreased the number of green (immature) berries. Rates of >500 mg/kg were effective in accelerating berry ripening, while 125 mg/kg had a limited effect. Maturity stage of the bean at time of application helped to determine the ethephon response; early application of ethephon had a more pronounced effect on berry ripening than late application. Ethephon applied early at rates of 1500 and 2000 mg/kg decreased fresh berry weight compared with all other treatments but parchment weight was unaffected. Selection of a suitable rate of ethephon from these data is difficult because berry ripening is offset by leaf drop. Variability of response was also observed.


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