Screening for Root-knot Nematode Resistance in Somaclonal Variants of Solanum quitoense Lam.

in HortScience
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  • 1 Dept. of Plant and Soil Sciences, Univ. of Delaware, Newark, DE 19717

Solanum quitoense is a perennial herbaceous plant native to the tropical regions of Colombia and Ecuador. It has attracted the attention of the international market because of the special taste of its fruits and its being a non traditional crop. The main problem in its culture is its susceptibility to root-knot nematodes, Meloido-gyne incognita (Kofoid & White) Chitwood. Two cultivars of S. quitoense were examined, `Baeza' and `Dulce'. The main objective of this research was to develop protocols for proliferation, rooting and establishment, and regeneration and screening for root-knot nematode resistance. S. quitoense was easy to proliferate, root and reestablish without using growth regulators. Regenerants were initiated from petioles and internodal stem sections cultured on MS medium supplemented with BA 1 to 10 mg·L–1. From 420 explants cultured for each cultivar, there were 226 regenerants for `Baeza' and 279 for `Dulce'. Screening of regenerants for root-knot nematode resistance was carried out in the greenhouse with the regenerants of `Dulce'. Twenty-one regenerants, inoculated with 1000 eggs per plant (determined based on a previous experiment), had five or fewer galls after 5 weeks. Follow-up greenhouse and in vitro screening experiments are presently ongoing.