Cultivated tomato (Lycopersicon esculentum / Solanum lycopersicum): This cultivated species is generally highly susceptible to which of the following?

Introduction / Context:
Root-knot nematodes (Meloidogyne spp.) are major pests of tomato. While some modern cultivars carry the Mi-1 resistance gene introgressed from wild relatives, the baseline cultivated tomato germplasm without such resistance is characteristically susceptible, making this an important target for breeding and integrated pest management.

Given Data / Assumptions:

• The question refers to cultivated tomato species sensu lato.
• Options include a pest (Meloidogyne) and unrelated plant species names.
• Susceptibility is asked, not cross-compatibility or host range of other plants.

Concept / Approach:
Meloidogyne spp. invade roots, induce giant cells, and cause galls that disrupt water and nutrient uptake. In the absence of the Mi-1 gene or other resistance sources, substantial yield loss can occur. Wild species such as L. peruvianum are used as resistance donors rather than being “agents” causing disease in cultivated tomato.

Step-by-Step Solution:

Verification / Alternative check:
Extension bulletins consistently report heavy losses in susceptible tomato cultivars; resistant varieties highlight the necessity of Mi-1 or similar genes to manage root-knot nematodes.

Why Other Options Are Wrong:

• L. peruvianum and S. melongena are plants, not causal agents of disease in tomato.
• Both (a) and (b): mixes a pest with a plant species, illogical.
• A. rhizogenes: while it can transform plants experimentally, “default” field susceptibility is not the context here.

Common Pitfalls:
Confusing donor species of resistance (wild tomatoes) with pathogens; breeders introgress genes from L. peruvianum to reduce susceptibility to Meloidogyne.

Final Answer:
Meloidogyne spp. (root-knot) nematodes