Richard L. Fery* and Judy A. Thies
Root-knot nematodes (Meloidogyne spp.) are major pests of pepper (Capsicum spp.) in the United States, and parasitism of susceptible plants can result in severe yield losses. Although cultivars belonging to the species C. annuum account for most of the peppers grown in the United States. Habanero-type cultivars belonging to the species C. chinense are becoming increasingly popular. Unfortunately, all commercial Habanero-type cultivars are susceptible to root-knot nematodes. In 1997, the USDA released three C. chinense germplasm lines that exhibit high levels of resistance to root-knot nematodes. The resistance in these lines is conditioned by a single dominant gene, and this gene conditions resistance to the southern root-knot nematode (M. incognita), the peanut root-knot nematode (M. arenaria race 1), and the tropical root-knot nematode (M. javanica). A recurrent backcross breeding procedure has been used to transfer the C. chinense root-knot nematode resistance gene in Habanero-type germplasm. Several root-knot nematode resistant, Habanero-type candidate cultivars have been developed. Each of these Habanero-type candidate cultivars has a compact plant habit and produces a high yield of orange-colored, lantern-shaped fruit.
Philip D. Dukes Sr. and Richard L. Fery
Richard L. Fery and Judy A. Thies
Richard L. Fery and Philip D. Dukes
Richard L. Fery and James M. Schalk
A replicated greenhouse study was conducted to confirm the availability of resistance to western Rower thrips in pepper germplasm. Host-plant resistance ratings confirmed earlier observations that there is a considerable amount of variability within pepper germplasm for reaction to F. occidentalis. Plants of `Keystone Resistant Giant', `Yolo Wonder L', `Mississippi Nemaheart', `Sweet Banana', and `California Wonder' were resistant to the insect and exhibited only mild symptoms of damage. Plants of `Carolina Cayenne', `Santaka', and `Bohemian Chili', however, exhibited the symptoms of severe thrips damage, i.e., poorly expanded, deformed, and distorted leaves; greatly shortened internodes; and severe chlorosis. The resistance to F. occidentalis in pepper appears to be due to tolerance mechanisms, not antixenosis (nonpreference) or antibiosis mechanisms. Thrips-resistant cultivars could be used as a cornerstone in an integrated pest management program for greenhouse pepper production.