Genetic variation and risks of introgression in the wild Coffea arabica gene pool in south‐western Ethiopian montane rainforests

Abstract

The montane rainforests of SW Ethiopia are the primary centre of diversity of Coffea arabica and the origin of all Arabica coffee cultivated worldwide. This wild gene pool is potentially threatened by forest fragmentation and degradation, and by introgressive hybridization with locally improved coffee varieties. We genotyped 703 coffee shrubs from unmanaged and managed coffee populations, using 24 microsatellite loci. Additionally, we genotyped 90 individuals representing 23 Ethiopian cultivars resistant to coffee berry disease (CBD). We determined population genetic diversity, genetic structure, and admixture of cultivar alleles in the in situ gene pool. We found strong genetic differentiation between managed and unmanaged coffee populations, but without significant differences in within-population genetic diversity. The widespread planting of coffee seedlings including CBD-resistant cultivars most likely offsets losses of genetic variation attributable to genetic drift and inbreeding. Mixing cultivars with original coffee genotypes, however, leaves ample opportunity for hybridization and replacement of the original coffee gene pool, which already shows signs of admixture. In situ conservation of the wild gene pool of C. arabica must therefore focus on limiting coffee production in the remaining wild populations, as intensification threatens the genetic integrity of the gene pool by exposing wild genotypes to cultivars.

Variation in bean morphology and biochemical composition measured in different genetic groups of arabica coffee (Coffea arabica L.)

“…diversity using diverse groups of materials such as cultivar, mutants, spontaneous/subspontaneous accessions (terms defined in Charrier and Eskes 2004) and hybrids as well as different marker systems (Aerts et al 2012;Aga et al 2003;Dessalegn et al 2008b). These studies indicated a limited genetic variability available for arabica breeding programs, even with the wild accessions (Aga et al 2003;Anthony et al 2001;WCR 2014).…”

Changing soil characteristics alter the arbuscular mycorrhizal fungi communities of Arabica coffee (Coffea arabica) in Ethiopia across a management intensity gradient

“…Coffee density is high because of the planting of local cultivars between the wild coffee individuals. Local cultivars did not result from rigorous breeding, however, and still represent very high genetic diversity (Aerts et al, 2012). Soil disturbance is high, and mulching and slashing of the herbaceous undergrowth is common.…”

Research on Automatic Identification of Substation Circuit Breaker Based on Shape Priors

“…Usually the template matching algorithm is used to identify the circuit breaker character: the character feature extraction and image (template edge feature, SIFT feature), by matching to find the relationship between the feature points, to determine the template matching window; or the use of the template and the image to be recognized the relativity of gray value, for in the image of the template may position. Metric function common to have absolute difference (Sum of Absolute Differences:SAD) [3], (Sum of Squared Difference: square SSD) [4], the normalized cross correlation (Normalized Cross Correlation: NCC) [5].…”