Origin

‘TigerPaw-NR’ is the product of a conventional backcross breeding procedure to transfer the dominant root-knot nematode resistance gene from a Scotch Bonnet accession into a classical Habanero-type background. The donor parent was PA-426 and the recurrent parent was PA-350. PA-426 is a M. incognita, M. arenaria, and M. javanica nematode-resistant, Scotch Bonnet-type germplasm line that was released by the USDA in 1997 (Fery and Thies, 1998b; Thies and Fery, 2001). PA-350, susceptible to root-knot nematodes, is a Habanero-type cultigen obtained from an heirloom collector. ‘TigerPaw-NR’ was derived from a single BC₄F₃ plant grown in 2002.

Description

‘TigerPaw-NR’ has a compact plant habit (height = 62 cm, width = 86 cm) and produces lantern-shaped, orange-colored fruit. The period from transplanting to first harvest of mature fruit ranges from 77 to 92 d in Charleston, SC. There are usually two pedicels per axil and the pedicel position at anthesis is intermediate. Flower petal color is white, corolla color is violet, and the stamens have white filaments and purple anthers. At full anthesis, the style is usually the same length or slightly longer than the stamen. The leaves are large and have a lanceolate shape. The stems and leaves are glabrous. There is no visible anthocyanin present on the stems, nodes, branches, petioles, or peduncles. The fruits are attached to the pedicel in a pendant manner (typically one fruit per cluster); the calyx margin shape is dentate; the annular constriction at the junction of the calyx and peduncle is absent; and the pedicels are short, curved, and slender. The fruits are deciduous, i.e., the pedicel and calyx usually remain on the plant at harvest.

The results of three replicated field studies conducted at Charleston, SC, indicate that the fruit characteristics and yield of ‘TigerPaw-NR’ are comparable to those of currently available Habanero-type cultivars (Table 1). Marketable yield ranged from 22,352 kg·ha⁻¹ (four harvest test) to 37,799 kg·ha⁻¹ (eight harvest test); the average marketable yield for the three studies was 27,555 kg·ha⁻¹. A typical fruit weighs 7.8 g and is campanulate or lantern-shaped (2.7 cm wide × 4.4 cm long) (Fig. 1). The shape of the peduncle attachment end of the fruit is truncate, the neck at the base of the fruit is absent, and the shape at the blossom end of the fruit is blunt. The fruit cross-section is slightly corrugated. The fruit wall is thin (1.7 mm). The color of immature fruit is green (Munsell color rating: 5.5 GY 4.8/5.3); the color of harvest-stage fruit is bright orange (Munsell color rating: 4.1 YR 6.0/9.6). The fruits are extremely pungent (348,634 Scoville heat units), and a typical fruit has three locules (average number of locules = 3.25).

Table 1.

Average fruit size and marketable fruit yield of the root-knot nematode-resistant Habanero-type pepper cultivar TigerPaw-NR and the root-knot nematode-susceptible pepper cultivar Habanero grown in three separate trials at Charleston, SC, 2003–2004.^z

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Typical fruit harvested from the root-knot nematode-resistant Habanero-type cultivar TigerPaw-NR.

Citation: HortScience horts 42, 7; 10.21273/HORTSCI.42.7.1721

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Typical fruit harvested from the root-knot nematode-resistant Habanero-type cultivar TigerPaw-NR.

Citation: HortScience horts 42, 7; 10.21273/HORTSCI.42.7.1721

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Typical fruit harvested from the root-knot nematode-resistant Habanero-type cultivar TigerPaw-NR.

Citation: HortScience horts 42, 7; 10.21273/HORTSCI.42.7.1721

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‘TigerPaw-NR’ is homozygous for a dominant gene that conditions resistance to root-knot nematodes (Fery and Thies, 1998a, 2000). This C. chinense resistance gene is allelic to the dominant gene that conditions much of the southern root-knot nematode resistance in the C. annuum cv. Carolina Cayenne (Fery and Thies, 1998a). ‘Carolina Cayenne’ is a highly resistant cultivar whose resistance is derived from the C. annuum cayenne-type cultivar Carolina Hot (Fery and Dukes, 1986). Fery and Dukes (1996) reported that the resistance in ‘Carolina Hot’ is conditioned by two genes, one dominant and one recessive; they demonstrated that the dominant gene in ‘Carolina Hot’ is allelic to the single dominant gene (N) that conditions the M. incognita resistance in the C. annuum cv. Mississippi Nemaheart. The N gene was first described in 1957 (Hare, 1957). It needs to be noted that the root-knot nematode resistance exhibited by both ‘Carolina Hot’ and ‘Mississippi Nemaheart’ has remained effective for decades; ‘Carolina Hot’ was released in the late 1950s (Martin and Crawford, 1958) and ‘Mississippi Nemaheart’ was released in the mid-1960s (Hare, 1966).

The new cultivar has exhibited a high level of resistance to the southern root-knot nematode in all greenhouse tests; the numbers of galls and egg masses on the roots have always been minimal. The results of an eight-replicate test conducted in greenhouse soil benches infested with M. incognita race 3 showed that ‘TigerPaw-NR’ roots yielded 97% fewer M. incognita eggs per g fresh root than did roots of the susceptible recurrent parent PA-350 (Table 2). The resistance exhibited by ‘TigerPaw-NR’ is equal to that exhibited by the donor of the resistant gene, PA-426.

Table 2.

Average root-gall index, average egg mass index, and average number of eggs per gram fresh root tissue for PA-426 (Scotch Bonnet-type donor parent of resistance gene), PA-350 (susceptible Habanero-type recurrent parent), and TigerPaw-NR plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (greenhouse experiment).^z

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The root-knot nematode-resistant ‘TigerPaw-NR’ is recommended for use by both commercial growers and home gardeners. It should be particularly valuable as a home garden cultivar because home gardeners do not have easy access to alternative production sites. Additionally, few nematicides are registered for noncommercial use, and most home gardeners are not licensed to purchase and apply nematicides.

Availability

Protection for ‘TigerPaw-NR’ is being sought under the Plant Variety Protection Act. Genetic material of this release will be deposited in the National Plant Germplasm System where it will be available for research purposes, including the development and commercialization of new cultivars. It is requested that appropriate recognition of source be given when this germplasm contributes to research or development of a new breeding line or cultivar.