Analysis of simple sequence repeat markers linked to coffee berry disease resistance genes in a segregating population of arabica coffee (Coffea arabica L.)

 

Kiguongo A.P.K.^1* , Omondi C. O.¹, Gichuru E. K.¹ and Kasili R. W².

 

Research Article | Published December 2014

International Journal of Biotechnology and Food Science, Vol. 2(8), pp. 156-166

 

 

¹Coffee Research Institute, P.O. Box 4 – 00232, Ruiru, Kenya.

²Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000 - 00200, Nairobi, Kenya.

 

*Corresponding author. E-mail: allankiguongo@gmail.com  

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Arabica coffee (Coffea arabica) production in Africa is majorly constrained by coffee berry disease (CBD) caused by Colletotrichum kahawae. Transfer of desired genes from related wild diploid Coffea species into the cultivated allotetraploid C. arabica has been known to confer better traits such as pest/disease resistance. Thus, this study was aimed at establishing microsatellite markers that co-segregate with resistance to CBD in an F2 population. Among the 12 simple sequence repeats (SSR) markers tested, six markers were polymorphic, but only two discriminated between the parents, F1 and the F2 population derived from a cross between resistant variety (Rume Sudan) and susceptible cultivar (SL 28). Phenotypic studies using Colletotrichum kahawae inoculum to screen F2 population was carried out in order to understand the segregation of CBD resistance as well as their association with SSR markers. Only two SSR markers, M 24 and Sat 227 showed the expected Mendelian segregation ratio (1:2:1) for single gene effect (d.f = 1.0, P < 0.05) in the chi-square (x2) analyses. In the phenotypic data analysis, the F2 population segregated in a 3:1 for a major gene action (R:S) ratio for resistant and susceptible plants, respectively. Therefore, there was a correlation between phenotypic data and molecular data with regard to resistance to Colletotrichum kahawae infection. The genotypes from F2 population that showed resistance to C. kahawae were putatively linked to two alleles/loci of SSR markers, M 24 (∼210bp) and Sat 227 (∼200bp). These diagnostic markers could be used in breeding programs where Rume Sudan is used as the donor parent to develop CBD resistant coffee varieties.

 

Keywords: Coffee berry disease, Colletotrichum kahawae, disease resistance, simple sequence repeats markers, segregating population.

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Citation: Kiguongo APK, Omondi CO, Gichuru EK, Kasili RW (2014). Analysis of simple sequence repeat markers linked to coffee berry disease resistance genes in a segregating population of arabica coffee (Coffea arabica L.). Int. J. Biotechnol. Food Sci. 2(8): 156-166.

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