Ecology and Development Series No. 10, 2003 - ZEF

More documents

Recommendations

Info

Current state of knowledge2.2 Taxonomy, genetic diversity and reproductive biology of Coffea arabica2.2.1 TaxonomyThe genus Coffea belongs to the family Rubiaceae, which has around 500 genera and over6000 species. Rubiaceae is one of the largest families of flowering plants, mostly trees andshrubs, and more rarely herbs. Most species of the family occur in the tropics, particularlyin the lower story of tropical rain forests.New species of the genus Coffea are continually being discovered. Many newspecies have been discovered in recent years in the forests of Eastern Africa (Bridson 1982)and Madagascar (Davis 2001; Davis and Rakotonasolo 2000, 2001a, 2001b). In total,around 92 species of Coffea are currently recognized, of which 45 species occur inMadagascar, 44 in Africa, and three in the Mascarenes (Dulloo 1998; Davis andRakotonasolo 2001a).Leroy (1980) recognized three subgenera of Coffea. These are: subgen. Coffea(ca. 90 spp.), subgen. Baracoffea (Leroy) Leroy (ca. 4 spp.), and a monotypic subgen.Psilanthopsis (A. Chev.) Leroy. According to Bridson (1994), however, it is not worthy toconsider Psilanthopsis as a subgenus, and recommended it to be placed in subgen. Coffea.C. arabica is the type species for the genus and belongs to the subgen. Coffea.Several phenotypically deviating populations and lines of cultivars have beenformally recognized as varieties of C. arabica (var. bourbon Choussy, var. typica Cramer,)but there has been no clear distinction between cultivars (including land races) and the wildpopulations (Bridson and Verdcourt 1988). The naming of botanical varieties of C. arabicain literature is confounded due to mix up with cultivars. Cultivars are actually to be namedunder a different system, the code for cultivated plants (Trehane et al. 1995) and are to betreated separate from naturally occurring infraspecific variation. Hence, further research isnecessary to clarify these issues.Sylvain (1955, 1958) attempted to systematically classify the coffee cultivarsgrowing in Ethiopia. In his classification, he recognized 12 major types based on tree habit,leaf color and size, calyx characteristics, size and shape of fruits and seeds, and the yieldingability. For naming, he used the names of the locality where the coffee types were found.The 12 Ethiopian coffee types of Sylvain (1955, 1958) are the Enarea, Jimma or Kaffa,15
Current state of knowledgeAgaro, Chochie, Zeghie, Wolkitie, Wallamo, Irgalem, Dilla, Arba Gougou, Harar andLoulo. He also admitted that his list of the distinct cultivars was not complete due to theinability to cover all coffee growing regions. Over 130 traditional landraces or farmers’cultivars have recently been recorded from different coffee growing regions of Ethiopia(Admasu et al. 1989; Demel and Assefa 1994; Tadesse et al. 2001). The distinctness ofthese cultivars needs further investigation. Known cultivars of C. arabica growing outsideof Ethiopia include ‘Blue Mountain’ in Jamaica, ‘French Mission’ in Kenya and Tanzania,‘Kent’s’ in India, ‘Mundo Novo’ in Brazil, ‘San Ramon’ and its segregate ‘Villalobos’ inCosta Rica to mention a few, which are derived from two main lines of cultivars (van derVossen 1985; Anthony et al. 2002).2.2.2 Genetic diversityCoffea arabica differs from other species in the genus in that it is the only tetraploid(2n=44) and self-fertile species. All others are diploid (2n=22) and self-infertile (Carvalho1952; Charrier and Berthaud 1985). Morphologically, C. eugenioides and C. congensis aremore similar to C. arabica (Friis 1979). Carvalho (1952) observed that C. arabica exhibitsthe cytogenetical behavior of allotetraploid plants, indicating that it has evolved from across between two wild diploid species. Based on morphological characteristics of hybridsof diploid coffee species and the haploid progenies of C. arabica, it has been suggested thatC. eugenioides and C. congensis (or C. canephora or C. liberica) are the putative diploidprogenitors of C. arabica (Carvalho 1952; Narasimhaswamy 1962; Charrier and Berthaud1985). On the other hand, Monaco (1968) argued that Coffea arabica could also be anautotetraploid species and suggested investigating other chromosome races in the wildpopulations of the species in Ethiopia.A definite conclusion on the origin of the diploid species parenting C. arabica hasnot yet been reached. However, recent analysis of the phylogenetic relationships of Coffeaspecies using internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA placedC. arabica in a group which encompasses diploid species originating from West andCentral Africa (Lashermes et al. 1997). The diploid species in this group (also calledcanephoroid group) include C. canephora, C. brevipes, C. congensis, C. humilis, C.16
Page 1: Ecology and Development Series No.
Page 4 and 5: Wäldern weist im Wesentlichen zwei
Page 6 and 7: 4.4 Discussion ....................
Page 8 and 9: General introduction1 GENERAL INTRO
Page 10 and 11: General introductionoutbreaks and e
Page 12 and 13: General introductionunfavorable cha
Page 14 and 15: General introductionand their patte
Page 16 and 17: Current state of knowledge2 STATE O
Page 18 and 19: Current state of knowledgeThe studi
Page 20 and 21: Current state of knowledgemore prom
Page 24 and 25: Current state of knowledgekapakata,
Page 26 and 27: Current state of knowledgecultivars
Page 28 and 29: Current state of knowledgehomegarde
Page 30 and 31: Current state of knowledgeseeded pl
Page 32 and 33: Current state of knowledgeHailu, un
Page 34 and 35: Current state of knowledgeraces are
Page 36 and 37: Description of the study area and s
Page 42 and 43: Floristic analysis of the undisturb
Page 72 and 73:
Floristic analysis of the undisturb
Page 74 and 75:
Impacts of human use on the forest
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Conservation of the wild Coffea ara
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Conclusions and recommendations7 CO
Page 134 and 135:
Conclusions and recommendations3. R
Page 136 and 137:
ReferencesBatisse M. 1986 Developin
Page 138 and 139:
ReferencesDavis A.P. and Rokotonaso
Page 140 and 141:
ReferencesESRI. 1996. ArcView GIS:
Page 142 and 143:
ReferencesIUCN 1992. Protected Area
Page 144 and 145:
ReferencesMesfin Ameha and Bayetta
Page 146 and 147:
ReferencesSmith R.F. 1985. A histor
Page 148 and 149:
ReferencesVan Jaarsveld A.S., Freit
Page 150 and 151:
Appendices9 APPENDICESAppendix 1 Li
Page 152 and 153:
AppendicesD. repandum (Vahl) DC, [H
Page 154 and 155:
AppendicesSapotaceaeAningeria altis
Page 156 and 157:
AppendicesAppendix 3 Families of va
Page 158 and 159:
AppendicesAppendix 5. ANOVA tables:
Page 160 and 161:
AppendicesAppendix 7 Height class d
Page 162 and 163:
AppendicesGFUNDFOR OLSFOR SF-NEW SF
Page 164 and 165:
AppendicesAppendix 10. List of loca
Page 166 and 167:
AppendicesNumber Family name Scient
Page 168 and 169:
AppendicesNumber Family name Scient
Page 170 and 171:
ACKNOWLEDGEMENTSI am very grateful
show all

Ecology and Development Series No. 10, 2003 - ZEF

Create successful ePaper yourself

Delete template?

Save as template?