Pests

Citrus Nematode

Citrus L.

The semi-endoparasitic nematode Tylenchulus semipenetrans causes 'slow decline' disease in citrus, affecting the root system and reducing overall tree productivity.

In the reference 19 varieties crop Citrus, where this is mentioned in the description.

The pathogen is Tylenchulus semipenetrans, represented by three main biological races: 'Citrus', 'Mediterranean', and 'Poncirus'. The differences between them lie in their ability to infect various host plant species, including olive and Poncirus trifoliata.

The disease manifests latently: general growth inhibition, chlorosis, reduction in leaf and fruit size, and twig dieback are observed. The root system acquires a characteristic 'dirty' appearance due to soil particles adhering to the gelatinous matrix secreted by female nematodes, which is accompanied by root thickening and decay.

The main source of breeding resistance is the species Poncirus trifoliata, in whose genome the dominant locus Tyr1 has been identified. This genetic region provides resistance to the 'Citrus' and 'Mediterranean' races, which is actively used in the creation of rootstocks to protect citrus trees from infection.

General information about the subject — on the page Nematodes.

Sources8

Varieties of Citrus mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.