Evaluation of a resistant line of tropical carrot to root-knot nematode Meloidogyne incognita using conventional method and molecular markers

• Published in: European journal of plant pathology Vol. 168; no. 2; pp. 363 - 371
• Main Authors: Manisha, Padmini, K., Umamaheswari, R., Reddy, D. C. Lakshmana, Dhananjaya, M. V., Rao, V. Keshava
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2024; Springer Nature B.V
• Subjects: Agriculture; Alleles; Biomedical and Life Sciences; Carrots; Ecology; Inoculation; Life Sciences; Marketability; Meloidogyne incognita; Nematodes; Pest resistance; Plant Pathology; Plant Sciences; Vegetables; Root knot nematode; Resistance; Screening; Carrot; Marker; gene
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-023-02758-0

Carrots are highly susceptible to root-knot nematodes (RKN) which reduce their marketability due to deformation of roots. Hence, there is a need to identify resistant sources against RKN to accelerate resistance breeding programmes in carrot. In the current study, forty-eight carrot accessions were screened by artificial inoculation of nematodes to locate the lines resistant to Meloidogyne incognita . Among all, Acc- 88 was found to be immune to M. incognita followed by Acc-72, Acc-145 and KSP-123 which showed a moderately resistant reaction. Acc -113B was highly susceptible while the other 44 lines showed a susceptible reaction towards M. incognita . The accessions were validated for the Mj gene using linked molecular markers conferring resistance to RKN. The immune line, Acc-88 amplified at 266 bp proving the presence of resistance allele and Acc-113B generated the product size of the susceptible allele revealing a polymorphic difference with the ESSR0110 marker. The Mj resistance locus carrying Acc-88 has the potential to introgress RKN resistance in susceptible varieties of carrot. The validated ESSR0110 co-dominant molecular marker is promising because it could effectively distinguish resistant and susceptible individuals, thus helps the breeder to develop stable source resistance to root knot nematode. This finding is the first report on identification of immune linse and linked molecular marker in tropical carrot against M. incognita.