‘Truhart-NR’, A Root-knot Nematode-resistant, Pimento-type Pepper

in HortScience

‘Truhart-NR’ is a new pimento-type pepper (Capsicum annuum L.) released 20 Oct. 2009 by the Agricultural Research Service of the U.S. Department of Agriculture. ‘Truhart-NR’ is a pimento-type cultivar that is homozygous for a dominant gene conditioning a high level of resistance to the southern root-knot nematode [Meloidogyne incognita (Chitwood) Kofoid and White], the peanut root-knot nematode [M. arenaria (Neal) Chitwood], and the tropical root-knot nematode [M. javanica (Treub) Chitwood]. ‘Truhart-NR’ is being released as a replacement for ‘Truhart Perfection’, a widely adapted and long popular pimento-type cultivar that is highly susceptible to root-knot nematodes.

Origin

In 2000, a recurrent backcross breeding procedure was initiated to incorporate the dominant root-knot nematode resistance gene (N) into the classical pimento-type “Perfection” genetic background (Fig. 1) (Fery and Dukes, 1996; Hare, 1957). The donor parent of the N resistance gene was ‘Mississippi Nemaheart’ and the recurrent parent was ‘Truhart Perfection’. ‘Mississippi Nemaheart’ was released by Mississippi State University in 1966 (Hare, 1966). Although ‘Mississippi Nemaheart’ itself is the product of a recurrent backcross breeding procedure (10 backcrosses) that used ‘Truhart Perfection’ as the recurrent parent, it was never used widely by industry because it was considered by many to produce a weak plant. ‘Truhart Perfection’ was released by the Georgia Experiment Station in 1943 (Cochran, 1943); it is susceptible to root-knot nematodes. ‘Truhart Perfection’ is an inbred selection from the original Perfection cultivar that was released by S.D. Riegel and Sons of Experiment, GA, in 1912 (Cochran, 1943). Both ‘Perfection’ and ‘Truhart Perfection’ were predominant cultivars for Georgia's large pimento pepper industry for a number of decades after their release; ‘Truhart Perfection’ is still recommended for use by specialty crop growers in several southern states. The ‘Truhart Perfection’ accession that was used as the recurrent parental line for the current release was derived from a sample of foundation seed increased at the Georgia Experiment Station in 1988. ‘Truhart-NR’ was derived from a single BC2F3 plant grown in 2006.

Fig. 1.
Fig. 1.

Pedigree of the root-knot nematode-resistant, pimento-type pepper cultivar Truhart-NR.

Citation: HortScience horts 46, 5; 10.21273/HORTSCI.46.5.815

Description

‘Truhart-NR’ is quite similar in appearance and maturity to ‘Truhart Perfection’. ‘Truhart-NR’ has an erect plant habit (height = 59 cm; width = 63 cm) and produces heart-shaped, dark red fruit (Table 1; Fig. 2). The foliage is dense and the fruits are well protected from sun scald. The period from transplanting to first harvest of mature fruit is ≈72 d at Charleston, SC. There is usually one pedicel per axil and the pedicel position at anthesis is pendant. Corolla color is white with yellow throat markings, corolla spots are absent, and the stamens have white filaments and purple anthers. At full anthesis, the length of the style is usually slightly longer than the stamen. The lanceolate-shaped leaves are medium-sized and have a medium green color. The stems and leaves are glabrous. The stems and nodes are green. There is an occasional presence of very slight anthocyanin pigmentation on the stems, slight to moderate pigmentation at the base of branches, very slight pigmentation on the petioles, and moderate pigmentation at the base of the pedicels. The seedling hypocotyl exhibits a moderate amount of pigmentation. The fruits are attached to the pedicel in a pendant manner (typically one fruit per cluster); the calyx margin shape is smooth for ripe fruit (midway between smooth and dentate for green fruit); the annular constriction at the junction of the calyx and pedicel is absent; and the pedicels are short to intermediate in length, curved, and thick. The fruits are persistent, i.e., the pedicel and calyx usually remain with the fruit at harvest.

Fig. 2.
Fig. 2.

Freshly harvested fruit of the root-knot nematode-resistant, pimento-type pepper cultivar Truhart-NR (left) and the root-knot nematode susceptible, pimento-type pepper cultivar Truhart Perfection (right).

Citation: HortScience horts 46, 5; 10.21273/HORTSCI.46.5.815

Table 1.

Average plant height, plant width, days from transplant to harvest, and marketable fruit yield for the root-knot nematode-resistant cultivar Truhart-NR and the root-knot nematode-susceptible cultivar Truhart Perfection grown in two separate field trials at Charleston, SC, 2007–2008.z

Table 1.

The results of two replicated field studies conducted in 2007 and 2008 at Charleston, SC, indicate that the fruit and yield characteristics of ‘Truhart-NR’ are superior to those of ‘Truhart Perfection’. Over the 2-year period, ‘Truhart-NR’ yielded an average of 16.7% more marketable fruit than did ‘Truhart Perfection’ (15,116 kg·ha−1 versus 12,957 kg·ha−1, respectively). ‘Truhart-NR’ fruit were also 6.9% heavier, 6.2% longer, and exhibited 4.3% thicker fruit walls (Table 2). A typical ‘Truhart-NR’ fruit weighs 67.8 g and is conical- or heart-shaped (5.64 cm wide × 7.36 cm long). The shape of the calyx 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 pointed. The cross-section of a typical fruit exhibits a slightly corrugated shape. The fruit wall is thick (4.41 mm). The color of immature fruit is dark green; the color of harvest-stage fruits is a deep dark red (Munsell color rating: 5.8 R 3.5/8.0). The fruits are sweet (non-pungent), and a typical fruit has three locules.

Table 2.

Comparison of fruit characteristics of the southern root-knot nematode-resistant cultivar Truhart-NR and the root-knot nematode-susceptible cultivar Truhart Perfection.z

Table 2.

‘Truhart-NR’ is homozygous for the dominant N gene that conditions a high level of resistance to root-knot nematodes. 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 (Table 3). The resistance exhibited by ‘Truhart-NR’ is equal to that exhibited by the root-knot nematode resistant bell-type cultivar Charleston Belle.

Table 3.

Average root-gall index and average egg mass index for ‘Truhart-NR’, ‘Truhart Perfection’ (susceptible recurrent parent), ‘Charleston Belle’ (resistant control), and ‘Keystone Resistant Giant’ (susceptible control) plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (Greenhouse Experiment, 2008).z

Table 3.

The root-knot nematode-resistant ‘Truhart-NR’ is recommended for use by both home gardeners and commercial growers. It is recommended particularly for use by organic farmers and growers of specialty crops because these segments of the pepper industry do not have easy access to alternative production sites or the needed nematicides and nematicide application equipment. Because the gene conditioning the root-knot nematode resistance trait is dominant, ‘Truhart-NR’ is potentially a valuable parental line for developing root-knot nematode-resistant hybrid pimento-type cultivars. ‘Truhart-NR’ should perform well in all areas where ‘Truhart Perfection’ has been grown successfully.

Availability

A limited quantity of ‘Truhart-NR’ breeder's seed is available for distribution to all interested research personnel and bona fide pepper seed producers. 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.

Literature Cited

  • CochranH.L.1943The Truhart Perfection pimientoGeorgia Expr. Sta. Bul. 224

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  • FeryR.L.DukesP.D.1996The inheritance of resistance to the southern root-knot nematode in ‘Carolina Hot’ cayenne pepperJ. Amer. Soc. Hort. Sci.12110241027

    • Search Google Scholar
    • Export Citation
  • HareW.W.1957Inheritance of resistance to root-knot nematodes in pepperPhytopathology47455459

  • HareW.W.1966New pimiento is resistant to nematodesMississippi Farm Res.2918

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Contributor Notes

The technical assistance of Floyd P. Maguire and Sharon Buckner, ARS-USDA, is gratefully acknowledged.

To whom reprint requests should be addressed; e-mail Richard.Fery@ars.usda.gov.

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Article Figures

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    Pedigree of the root-knot nematode-resistant, pimento-type pepper cultivar Truhart-NR.

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    Freshly harvested fruit of the root-knot nematode-resistant, pimento-type pepper cultivar Truhart-NR (left) and the root-knot nematode susceptible, pimento-type pepper cultivar Truhart Perfection (right).

Article References

  • CochranH.L.1943The Truhart Perfection pimientoGeorgia Expr. Sta. Bul. 224

    • Export Citation
  • FeryR.L.DukesP.D.1996The inheritance of resistance to the southern root-knot nematode in ‘Carolina Hot’ cayenne pepperJ. Amer. Soc. Hort. Sci.12110241027

    • Search Google Scholar
    • Export Citation
  • HareW.W.1957Inheritance of resistance to root-knot nematodes in pepperPhytopathology47455459

  • HareW.W.1966New pimiento is resistant to nematodesMississippi Farm Res.2918

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