Evaluation of tomato genotypes for resistance to root-knot nematodes

Tomato ( Solanum lycopersicum ) is one of the most popular vegetable crops worldwide, owing to its high nutritive value and diversified use. Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot nematodes ( Meloidogyne spp.), which are responsible for huge economic yield losses. The losses, however, can be averted through use of resistant varieties. A study was conducted to evaluate tomato genotypes reaction to root-knot nematodes. Five inoculum levels, 100, 500, 1000, 1500 and 2000 root-knot nematode eggs per 1.6 litres of soil per pot were inoculated on tomato seedlings. A total of 33 genotypes were screened for resistance to Meloidogyne spp. Nine tomato genotypes were collected from Burkina Faso, eight from Vietnam, seven from the United States of America, three genotypes from South Africa, and six from local agro-dealers and farmers in Ghana. The genotypes were screened in pots and the field for host resistance to Meloidogyne spp. The 1500 eggs per plant inoculation level resulted in the highest number of eggs, juveniles and fresh root weight. Among the 33 genotypes screened, Tomato Mongal T-11 and Tomato Beef Master were found to be highly resistant to Meloidogyne spp. and also recorded the lowest reproductive factors of 0.71 and 0.53, respectively.La tomate ( Solanum lycopersicum ) est une des plus populaires l\ue9gumes au monde suite \ue0 sa valeur plus nutritive et utilisation diversifi\ue9e. Par ailleurs, sa production est limit\ue9e par des n\ue9matodes parasites des plantes, sp\ue9cialement les galles racinaires ( Meloidogyne spp.) et sont responsables de lourdes pertes \ue9conomiques. Ces pertes, par ailleurs, peuvent \ueatre \ue9vit\ue9es par l\u2019utilisation des vari\ue9t\ue9s r\ue9sistantes. Une \ue9tude \ue9tait conduite pour \ue9valuer la r\ue9action des g\ue9notypes de tomates aux galles racinaires des n\ue9matodes. Cinq niveaux d\u2019inoculum \ue0 savoir 100, 500, 1000, 1500 et 2000 galles d\u2019oeufs de n\ue9matodes par 1.6 litres de sol par pot \ue9taient inocul\ue9s sur les plantules de tomates. Un total de 33 g\ue9notypes \ue9taient r\ue9sistants au Meloidogyne spp. Neuf g\ue9notypes de tomates \ue9taient collect\ue9s du Burkina Faso, huit du Vietnam, sept des Etats Unis d\u2019Am\ue9rique, trois g\ue9notypes d\u2019Afrique du Sud et six provenant des vendeurs et fermiers locaux du Ghana. Les g\ue9notypes \ue9taient test\ue9s en pots et en champ pour r\ue9sistance de l\u2019 h\uf4te au Meloidogyne spp. Les 1500 oeufs par niveau d\u2019inoculation de plants ont induit un nombre le plus \ue9lev\ue9 d\u2019oeufs, raciness juveniles et le poids des racines fra\ueeches. Parmi les 33 g\ue9notypes test\ue9s, Tomato Mongal T-11 et Tomato Beef Master ont \ue9t\ue9 trouv\ue9s les plus r\ue9sistantes au Meloidogyne spp. et avaient aussi enregistr\ue9 les facteurs les moins reproductifs de 0.71 and 0.53, repectivement