AC Sunbury: A new light yellow-fleshed medium early table potato cultivar with resistance to golden cyst nematode

American Journal of Potato Research, Nov/Dec 2002 by Murphy, Agnes, Tarn, Richard, De Jong, Henry, Arsenault, Walter, Tai, George C C

ABSTRACT

AC Sunbury is an attractive, round /oval, medium early table potato with light yellow flesh and very good culinary quality, especially when baked. It produces yields comparable to Jemseg or Superior at 80 days and is resistant to the golden cyst nematode Rol and to infection by PVY. It was bred at the Potato Research Centre, Agriculture and Agri-Food Canada, Fredericton, NB, and released in 2001.

RESUMEN

AC Sunbury es una atractiva papa comercial semiovalada y de maduracion medianamente precoz con pulpa de color amarillo claro y muy buena cualidad culinaria, especialmente cuando se hornea. Sus rendimientos a los 80 dias son similares a las variedades Jemseg o Superior y es resistente al nematodo dorado del quiste Rol y a la infeccion por PVY. Fue multiplicado en el Centro de Investigacion de la Papa Fredericton, AAFC en ingles, y liberado en el ano 2001.

INTRODUCTION

AC Sunbury is adapted as a medium early, light yellow-- fleshed cultivar in Eastern Canada and Quebec. The round-oval shallow-eyed tubers have a very good appearance and culinary quality, especially when baked This cultivar was named after a county in New Brunswick, Canada. Sunbury County was established in 1765 as a county of Nova Scotia 19 years before New Brunswick became a province. At that time, it comprised much of what is now western New Brunswick. Today, Sunbury County is located in central New Brunswick along the St. John River near where this cultivar was evaluated for the early market.

AC Sunbury was bred and selected within the potato-breeding program of Agriculture and Agri-Food Canada (AAFC) at the Fredericton, NB, Potato Research Centre. Tested as selection F80054, it was registered for certification in Canada in 2001 and released as a public cultivar, registration number 5297 (Figure 1).

AC Sunbury was selected from the progeny of a cross, made in 1978, between Raritan (female parent) and Y66-13-636. Raritan was developed at the Agriculture and Agri-Food Canada Research Station and later released by Rutgers University for development and introduction in New Jersey. It is able to produce tubers of high specific gravity under relatively high temperatures and has good table qualities (Campbell and Young 1970).Y66-13-636 (also known as Agitato) is a yellow-fleshed selection developed by the late Dr. Wiersema in Wageningen, the Netherlands (wiezyfisld et al. 1997). Y66-13-636 was specifreally developed to be used as a parent for disease resistance; it has extreme resistance to PVY, PVA, and PVX and is also resistant to the golden cyst nematode (Globodera rostochiensis pathotype Rol). The PVY resistance of Y66-13-636 can be traced back to Solanum stoloniferum; its nematode and PVX resistance has been derived from the Andigena clone CPC1673.

The pedigree of AC Sunbury is shown in Figure 2.

Description

PLANTS: Growth habit: vines are medium in size, erect with little branching. Stems: anthocyanin coloration is absent, wings are inconspicuous and nodal swelling is absent. Leaves: yellowish green. Pubescence: very little on lower leaf surfaces. Leaf type: open. Terminal leaflet: medium ovate, tip acuminate, base cordate and moderately asymmetrical. Primary leaflets: medium ovate, 3.5 pairs, tip acuminate, base cordate and moderately asymmetrical. Secondary leaflets: 6-8 in number. Petioles and midribs: pubescence almost absent on rachis, anthocyanin colouration absent on rachis and petioles.

INFLORESCENCE: medium profuse flowering with low numbers of flowers per inflorescence. Buds: anthocyanin coloration absent. Calyx: anthocyanin coloration absent. Corolla: medium size, white with an inconspicuous star. Stamens: broad cone shape, bright yellow anthers. Stigma: capitate, medium green.

FERTILITY: medium pollen shed and quality; low frequency of open pollinated berries in the field. Productive when used as a female in controlled pollinations.

TUBERS: Shape: typically oval. The mean width to length is 0.80, the mean thickness to length is 0.65, and the mean thickness to width is 0.81. Skin: light yellow. Eyes: shallow, pink eyes predominantly apical in distribution. Flesh: light yellow. Sprouts: ovoid, with very slight pubescence. Pink at the base. The sprout tip is medium open with little pubescence and green. There is low frequency of root initials and medium protrusion of lenticels. Lateral shoots: medium to long. Dormancy: medium.

MATURITY: the haulm maturity is medium early.

Disease Resistance

AC Sunbury is resistant to the golden cyst nematode (G. rostochiensis Rol) and to infection by PVY. It is moderately susceptible to common scab (Streptomyces scabies) and is susceptible to PLRV, wart (Synchytfium endobioticum), verticillium wilt (V.dahliae), dry rot (Fusarium sambucinum f.6), and alternaria early blight (A. solani). AC Sunbury is very susceptible to late blight (Phytophthora infestans). Summary provided in Table 1.

AC Sunbury exhibited typical foliage and tuber symptom expression in a bacterial ring rot (Clavibacter michiganensis ssp. sepedonicus) test in 1986 conducted in NB.