ARS | Publication request: Evaluation of coffee genotypes for root-knot nematode resistance

Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 5, 2010
Publication Date: December 29, 2010
Citation: Cabos, R.Y., Sipes, B.S., Nagai, C., Serracin, M., Schmitt, D.P. 2010. Evaluation of coffee genotypes for root-knot nematode resistance. Nematropica 40:191-202.

Interpretive Summary: Root-knot nematodes, Meloidogyne spp., adversely affect production of Coffea arabica in many coffee growing regions. Grafting rootstocks with resistance or tolerance to the nematode has shown to be the most economical and environmentally compatible way to control these pests. In Hawaii, C. liberica var. dewevrei is grafted on C. arabica cv. Typica to control the Kona Coffee Root-knot Nematode, M. konaensis. New rootstocks are continually being developed or discovered from wild accessions. For effective long-term management, there is a need to assay these rootstocks against different root-knot nematode species and environmental conditions. This study confirmed that the root system of C. liberica var. dewevrei grew vigorously in the presence of M. konaensis and M. hapla while C. canephora cv. Nemaya and C. purpurea had the lowest nematode populations. It also demonstrated that variability in nematode resistance levels can occur from the outcrossing of these diploid species and steps should be taken to protect the integrity of those resistant lines.

Technical Abstract: Meloidogyne konaensis causes severe damage to the root systems of Coffea arabica cv. Typica ‘Guatemala’ grown in Kona, Hawaii. Farmers currently employ grafting of the nematode tolerant C. liberica var. dewevrei ‘Fukunaga’ to C. arabica cv. Typica scions. Greenhouse experiments confirmed C. liberica’s tolerance to M. konaensis and M. hapla infection. Vigorous, healthy roots and rapid shoot growth occurred despite the presence of galls and high nematode populations. Coffea purpurea and C. canephora cv. Nemaya had reduced root-knot nematode populations in comparison to C. arabica although C. purpurea did not have the vigorous growth that was observed in C. liberica and C. canephora. Nematode populations were variable among C. liberica and C. canephora individuals, suggesting outcrossing and genetic variation among plants. The screening of C. liberica and C. arabica cultivars from Central America confirmed C. liberica had the least amount of root damage from M. konaensis infestation although C. arabica cvs. Caturra and Eritrean Moca demonstrated low nematode reproduction and moderate levels of tolerance to M. konaensis.