Screening of cauliflower (Brassica oleracea var. botrytis L.) genotypes for resistance to the root-knot nematode (Meloidogyne incognita)

Abstract

The root-knot nematode (RKN) Meloidogyne spp. incurs substantial economic losses in vegetable crops. The present investigation involved glass-house-based screening performed by artificial inoculation of a set of 62 cauliflower accessions against RKN infestation. The PAUCE-292 genotype exhibited a resistant reaction to RKN infestation while genotypes PAUCE-15, PAUCE-16, PAUCE-19C and PAUCM-PI exhibited a moderately resistant reaction. Nematode inoculation reduced various growth parameters including plant height, plant weight and root length as compared to control but a higher percent reduction was recorded for the susceptible and highly susceptible genotypes. The root galling intensity was recorded to be high in susceptible and highly susceptible genotypes. The root-morphoanatomy studies on selected genotypes revealed no specific association of the studied traits with RKN reaction. But, optical microscopy revealed elaborate lignification and gall formation on RKN inoculation in susceptible PAUCM-SD3 and highly susceptible PAUCM-STAR accessions. The total phenol and flavonoid contents were maintained at significantly high levels in resistant genotype(s) in the initial 2.5-week post-inoculation of nematode juveniles. Therefore, this study provides biochemical cues on the mechanism of RKN resistance in cauliflower accessions.

Graphical Abstract

Keywords:

• Galling index
• Meloidogyne incognita
• microscopy
• resistance
• screening
• susceptibility

Author contributions

Conceptualisation: Ruma Devi, Sukhjeet Kaur, Anu Kalia, and Tarseem Singh Dhillon. Methodology: Ruma Devi, Sukhjeet Kaur, and Anu Kalia. Formal analysis and investigation: Pardeep Kumar and Anu Kalia. Writing – original draft preparation: Pardeep Kumar. Writing – review and editing: Ruma Devi, Sukhjeet Kaur, Anu Kalia, and Tarseem Singh Dhillon. Funding acquisition: Ruma Devi and Tarseem Singh Dhillon. Resources: Ruma Devi and Tarseem Singh Dhillon. Supervision: Ruma Devi and Tarsem Dhillon.

Disclosure statement

No potential conflict of interest was reported by the authors.