Genetic parameters of resistance to Meloidogyne incognita in melon

Parâmetros genéticos da resistência a Meloidogyne incognita em meloeiro

ABSTRACT:

In order to assess the genetic control of resistance in the melon ‘Gaúcho Redondo’ to the root-knot nematode Meloidogyne incognita, an experiment was conducted in a randomized complete block design with three blocks and six treatments using the parental lines ‘Gaúcho Redondo’ (P₁ resistant) and JAB 20 (P₂ susceptible), as well as F₁, F₂, and backcross generations (RC₁P₁ and RC₁P₂). Seventy days after inoculation, individual plants were evaluated for resistance using the nematode reproduction factor (RF). The hypothesis of monogenic inheritance was rejected by the chi-square test (χ²), and results indicated that resistance is controlled by more than one gene locus, as confirmed by the quantitative analysis that revealed the presence of six genes.

Key words:
Cucumis melo; genetic inheritance; plant breeding; reproduction factor