Assessment of root-knot nematode resistance in eggplant accessions by using molecular markers

Eggplant is one of horticultural crop species that is widespread in tropical and subtropical regions. Root-knot nematode (Meloidogyne incognita) is a biotic factor that is becoming a serious problem because it affects the eggplant root system and physiological activities, resulting in reduced eggplant growth and yield. This study was conducted to quantify eggplant resistance to nematodes in the field and to identify genetically resistant genes by using cleaved amplified polymorphic sequence markers. Results showed that the eggplant accessions that were classified as moderately resistant, namely Solanum aculeatissimum (SL-TE 74 and SL-TE 590) and Solanum torvum (SL-TE 589), were basically wild relatives and had fewer galls and female nematodes than other accessions. Both wild relatives have the potential to become donors for the development of nematode-resistant cultivars. The eggplant accessions SL-TE 44 and SL-TE 579 were identified as highly susceptible. Molecular testing with Mi-1 markers (Rex) revealed that all of the eggplant accessions produced 550 bp DNA fragments. The DNA fragments of SL-TE 74 and SL-TE 590 were cut into sizes of 550, 450, and 240 bp, whereas SL-TE 589 were divided into sizes of 550 and 240 bp. In the amplification by using the C8B marker, the amplification fragments of SL-TE 589 had sizes of 1500, 1100, and 500 bp, whereas SL-TE 74 and SL-TE 590 had sizes of 2000 and 900 bp. However, the susceptible eggplant accessions only produced one 700 bp DNA fragment. © Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO) 2021.