Reproduction of Meloidogyne spp. on Resistant Peanut Genotypes from Three Breeding Programs.

Area of Science:

• Plant Pathology
• Agronomy
• Nematology

Background:

• Root-knot nematodes (Meloidogyne spp.) are significant pests of peanut (Arachis hypogaea).
• Three species, Meloidogyne arenaria (Ma), M. hapla (Mh), and M. javanica (Mj), commonly parasitize peanut.
• Developing peanut cultivars with broad resistance is crucial for effective nematode management.

Purpose of the Study:

• To evaluate peanut genotypes, bred for resistance to Ma, for their efficacy against Mh and Mj.
• To identify potential sources of resistance for developing broadly resistant peanut cultivars.

Main Methods:

• A completely randomized factorial experiment was conducted.
• Five peanut genotypes with varying resistance to Ma were tested.
• Four nematode populations (two Ma isolates, one Mh isolate, one Mj isolate) were used.

Main Results:

• Peanut genotypes COAN and AT 0812 showed high resistance to Ma and Mj, with significantly fewer eggs produced compared to susceptible 'Georgia Green'.
• Genotype C209-6-13 exhibited moderate resistance to Ma and Mj.
• None of the tested peanut genotypes displayed significant resistance to Mh.

Conclusions:

• Resistance to Ma and Mj in peanut does not guarantee resistance to Mh.
• The lack of broad-spectrum resistance, particularly to Mh, is a concern for peanut production.
• Future breeding programs should prioritize incorporating genes for Mh resistance and combining resistance to multiple Meloidogyne species.