ribes currant gooseberry germplasm genebank gene bank genetics corvallis
NCGR-Corvallis - Ribes Germplasm
by Kim E. Hummer, Research Leader/Curator
The genus Ribes L., the currants and gooseberries, includes more than 150 described species of shrubs which are native throughout Northern Europe, Asia, North America, and in mountainous areas of South America and northwest Africa (Brennan, 1996). Only about ten or twelve of these species comprise the primary gene pool from which domesticated currants and gooseberries were developed. The discussion in this chapter will focus on the background and cryopreservation of these economically important species.
Total world Ribes acreage (Table 1)was stable over the past several decades although the breakup of the former Soviet Union greatly increased fruit availability. Black currants, the major crop, are primarily grown for the juice market. They are also valued for production of jams, jellies, liqueurs, such as "Creme de cassis" in France, for the conversion of white wines to rose and as flavorants and colorants for dairy products. Black currant juice has intense flavor, color, high ascorbic acid, and other antioxidant levels which are now becoming recognized for nutraceutical properties. Poland, the Russian Federation, United Kingdom, and the Scandinavian countries lead the world production of black currants.
Red currants are valued for fresh market and for the production of preserves and juice. The main red currant producers are Poland, Germany, Holland, Belgium, France, and Hungary. Gooseberries, which are eaten fresh or processed into pies and jams, are primarily grown in Poland, Germany, and Hungary (Brennan, 1996). Several species of currants have ornamental qualities for plant habit, flowering, or fall foliage.
Ribes production is negligible in North America because of white pine blister rust, Cronartium ribicolaFisch., a disease introduced from Asia, which kills susceptible five-needled white pines. Ribes and Pinus L. subgenus Strobus are alternate hosts for this disease. Since the early 1900's, Ribes culture was restricted in parts of the United States in an attempt to curtail white pine blister rust.
Ribes was originally placed in the Saxifragaceae (Engler and Prantl, 1891; Vetenant,1799), but more recent taxonomic treatments classify the genus in the family Grossulariaceae because of wholly inferior ovary, totally syncarpous gynoceum, and fleshy fruit (Cronquist, 1981; Lamarck and De Candolle, 1805; Sinnott, 1985).
Early classifications also recognized two genera, Ribes, and Grossularia (Berger, 1924; Coville and Britton, 1908; Komarov, 1971). Numerous infrageneric classifications are proposed for these two genera. Prevalent monographs recognize a single genus, Ribes (de Janczewski, 1907; Sinnott, 1985). Crossability between gooseberry and currant species supports the concept of a single genus (Keep, 1962). De Janczewski (1907) subdivided the genus into six subgenera: Coreosma,the black currants; Ribes (=Ribesia), the red currants; Grossularia, the gooseberries; Grossularioides, the spiny currants; Parilla, the Andean currants; Berisia, the European alpine currants
The centers of diversity for Coreosma, Ribes, and Berisia include Northern Europe, Scandinavia and the Russian Federation (Jennings et al., 1987); and for Grossulariain the Pacific Northwest of North America (Rehder, 1986). In addition several species of black currants with sessile yellow glands are native to South America.
The basic chromosome number of Ribes is x = 8 (Zielinski, 1953) and all species and cultivars are diploid. The chromosome complement and karyotype are highly uniform (Sinnott, 1985) and the chromosomes are 1.5 to 2.5 mm (Darlington, 1929). Mitotic and meiotic processes are also highly uniform (Zielinski, 1953).
The principal evolutionary pressure in the genus appears to be geographical adaptation (Sinnott, 1985). Messinger et al. (1999) examined subgeneric taxa of Ribes for restriction site variation in two cpDNA regions. While several infrageneric lineages were strongly supported, Grossularioidesspecies were unexpectedly united with those from Grossularia. Coreosma species exhibited high divergence and were not monophyletic in the analysis. Messinger et al. (1999) consider two possible, not mutually exclusive, evolutionary scenarios for Ribes: 1) long periods of stasis is interrupted by sudden radiation of species; 2) gene flow due to hybridization as a force for diversification.
Ribes is cultivated for edible fruit, ornamental plant habit, and bloom. The main economically important crop groupings include the black currants, red and white currants, gooseberries, hybrid berries, and ornamentals. The important species within each of these crop groupings are discussed below.
Coreosma,the subgenus for black-fruited currants, has sessile resinous glands. The species of most economic importance is R. nigrum L., which is native through northern Europe and central and northern Asia to the Himalayas and includes subsp. europaeum, subsp. scandinavicum, and R. nigrum var.sibiricum Wolf (Brennan, 1996).
Ribes nigrumis an unarmed, strongly aromatic shrub, growing as tall as 2 m (Rehder, 1986). The leaves are lobed, up to 10 cm per side, glabrous above, slightly pubescent with numerous sessile, aromatic glands beneath; the racemes droop and have 4 to 10 flowers. The flowers have reddish- or brownish-green campanulate hypanthia and recurved sepals. The whitish petals are about two-thirds as long as the sepals. The fruits are globose, up to 10 mm diameter, and are generally shiny black when ripe, although green- and yellow-fruited forms exist (Liberty Hyde Bailey Hortorium, 1976). This species was domesticated within Northern Europe by 1600 and was described in early herbals (Brennan, 1996). Recent breeding efforts have doubled fruit size compared to wild fruits. Breeders cross R. nigrum with R. ussuriense Jancz., R. dikuschaFisch. and R. nigrumvar. sibiricum for disease resistance; with R. bracteosum Dougl. for longer racemes resulting in higher yield (Brennan, 1996). Ribes hudsonianum Rich., the northern North American black currant, and R. americanum Mill., the American black currant, have desirable traits which may be useful for broadening the gene pool. Ribes nigrum cultivars have a range of descriptive characters (Table 2)
Ribes, the red currant subgenus, has crystalline glands on young growth (Brennan, 1996). Several species have economic importance: selections of R. sativum Syme (= R. vulgare Jancz.) were initially made from native stands in northwestern Europe. Ribes petraeumWulf. a montane species was also selected from the wild, while most of the cultivated red currants were derived from R. rubrum L., a Scandinavian species which is native as far north as 70 °N latitude (Brennan, 1996). R. rubrum is an unarmed shrub that grows to 2 m (Rehder, 1986). The shoots are glabrous or have glandular hairs. Stems are covered with a smooth pale yellow bark. The leaves are deeply cordate, 3- to 5- lobed, 6 x 7 cm in diameter. Flowers, which occur on long racemes, are greenish tinged with purple. The hypanthium is almost flat and the petals are very small. The fruit is globose, 6 to 10 mm in diameter, red and glabrous.
Ribes triste Pallas is the North American red currant, with similar fruit quality to European red currants, but not developed for cultivation. Two additional species, Ribes spicatum Robs. in Norway, and R. multiflorum Kit. in England, are used in red currant genetic improvement programs. White and pink currants are a color form of the red species.
Gooseberry species have nodal spines. The European gooseberry, R. uva-crispa L. (= R. grossularia L.), native in the United Kingdom eastward through northern Europe, the Caucasus, and North Africa, is most frequently selected for cultivar development (Brennan, 1996). R. uva-crispa is a spiny shrub that grows as much as 1.5 m tall (Liberty Hyde Bailey Hortorium, 1976). Stems have two to three spines at the nodes. Leaves are as large as 5 x 6.5 cm, sparsely pubescent or glabrous. Flowers occur in axillary clusters of one to three (much fewer than those on currant racemes), are pale green, sometimes pinkish, and have a hemispherical hypanthium, reflexed sepals, and short white petals. The fruit, which can be hispid, is globose to ovoid, about 10 mm in diameter, green, yellow, or purplish-red.
American species, such as R. divaricatum Dougl., R.hirtellum Michx and R. oxyacanthoides L. are used extensively in breeding with the European gooseberry. In England in the late eighteenth to nineteenth centuries, groups of amateur growers formed organizations with the purpose of increasing gooseberry fruit size and improving quality. These groups were quite successful and the crop thrived until the introduction of American powdery mildew, Sphaerotheca mors-uvae(Schw.) Berk. The gooseberry cultivars of the time were quite susceptible and acreage was greatly reduced (Brennan, 1996).
Ribes x nidigrolaria Bauer is a hybrid cross of black currants with gooseberries (Brennan, 1996). These man-made hybrids, commonly referred to as jostaberries, are very vigorous, do not have the acrid odor of black currants, have no or reduced spines, and are disease resistant. These cultivars are grown more by homeowners rather than commercial growers. Their disease resistance and large size fruit are popular with organic farmers.
Ornamental and flowering Ribes species have a broad range of colors. The American species, R. aureum Pursh and R. odoratum Wendl. have fragrant yellow flowers with tubular hypanthia that bloom in spring (Rehder, 1986). The fruits are black but do not have the "black currant odor" characteristic of R. nigrum. Another American species, R. sanguineum Pursh, has a range of flower color variants from white to dark red-purple, and is used in landscape plantings for spring bloom and wildlife habitat. Unfortunately, this species tends to be susceptible to white pine blister rust (Hummer and Finn, 1999). Some of the American gooseberries species, such asR. speciosum Pursh., R. lobbii Gray , and R. menziesii Pursh have very attractive fuschia-like flowers and are planted for their ornamental landscape attributes (Brennan, 1996).
The genus Ribes is fairly robust. Most species are broadly distributed and are not in danger of extinction. However, the World Conservation Monitoring Center 1997 Red List of Threatened plants includes 18 Ribes species. Ribes kolymense (Trautv.) Komarov ex Pojark is extinct from the former Soviet states; three American and one Sardinian species are endangered; six American are vulnerable; two from the Pacific Northwest, another Sardinian and a Chilean species are rare; three Russian species are indeterminate (Table 3) . Ribes ussuriense, one of the Russian species listed as indeterminate, contains the dominant gene, Cr, for immunity from white pine blister rust (Brennan, 1996). Genes from this species have allowed the cultivation of black currants in white pine blister rust restricted zones of the United States.
The Endangered Species Act of the United States (Department of the Interior, Fish and Wildlife Service, 50 CFR Part 17) lists the Miccosukee gooseberry, R. echinellum(Cov.) Rehder (Table 3). This spiny-fruited gooseberry species whose native habitat occurs along the shoreline of Lake Miccosukee near Monticello, Florida, and in limited locations in South Carolina and Georgia, is threatened by encroaching human development. Several accessions of this species are maintained ex situ at the National Clonal Germplasm Repository at Corvallis, Oregon. The Oregon National Heritage Program lists R. cereum var. colubrinum Hitchc. as rare, and R. divaricatum and R. klamathense(Cov.) Fedde as indeterminate (Table 3).
Currants root readily from dormant stem cuttings taken in the fall, or softwood taken in the spring. A high percentage of black currants root well from any type of cutting but red currants tend to root less well (Brennan, 1996). Nurseries in milder climates, such as that of the Pacific Northwest of the United States, cut 15 cm long stems of black currant cultivars in late October and plant the stems covering the lower two to three nodes with soil. The plants remain in the field throughout the winter while roots begin forming on the cuttings. The rooted cuttings are dug and shipped in the early spring.
Gooseberries, particularly cultivars derived from European species, root much less readily than do currants. Generally hardwood cuttings with basal application of auxin root with most success. Some gooseberries will not root readily by cuttings. In these cases mound layering or grafting must be attempted. Budding or whip-and-tongue grafting, with similar procedures to those used for temperate fruit trees, can be performed in the dormant season. Clones of R. aureum or R. odoratum have been selected for rootstocks (Harmat et al., 1989).
Example Cultivar Descriptors
Ribescultivars have a range of descriptive characters (Table 2). Many of these characters, such as cold hardiness, chilling requirement and dormancy, could influence their ability to be stored for long periods of time in cold storage as tissue culture plants or to be placed in cryopreservation.
Berger, A. 1924. A taxonomic review of currants and gooseberries. Bull. New York State Agric. Exp. Sta. 109.
Brennan, R. M. 1996. Currants and Gooseberries. Chapter 3 pp. 191-295 in: J. Janick and J. N. Moore (eds.) Fruit Breeding, Vol. II Vine and Small Fruit Crops. John Wiley & Sons. Inc. N.Y.
Coville, F. V. and Britton, N. L. 1908. Grossulariaceae. N. Am. Fl. 22:193-225.
Cronquist, A. 1981. An integrated system of classification of flowering plants. Columbia Univ. Press, New York.
Darlington, C. D. 1929. A comparative study of the chromosome complement in Ribes. Genetica 11:267-269.
Engler, A. and Prantl, K. 1891. Ribesioideae. Naturl. Pflanzenfam. 3:97-142.
Hamat, L., A. Porpaczy, D. G. Himelrick, and G. J. Galletta. 1989. Currant and Gooseberry Management. Chapt. 6, pp. 245-272. In: G. J. Galletta and D. G. Himelrick, (eds.) Small Fruit Crop Management. Prentice Hall. New Jersey.
Janczewski, E. de. 1907. Monograph of the currants Ribes L. (in French). Mem. Soc. Phys. Hist. Nat. Geneve. 35: 199-517.
Jennings, D. L., Anderson, M. M., Brennan, R. M. 1987. Raspberry and blackcurrant breeding. p. 135-147. In: A. J. Abbot and R. K. Atkin (eds.). Improving vegetatively propagated crops. Academic Press, London.
Keep, E. 1962. Interspecific hybridization in Ribes. Genetica 33:1-23.
Komarov, V. L. (ed.). 1971. Flora of the [former] USSR Vol. IX p. 175-208. In: Ribesioideae Engl. (Translated from the Russian by the Israel Program for Scientific Translation, Jerusalem). Keter, London.
Lamarck, J. B., and De Candolle, A. P. 1805. Flore Francaise. Desray, Paris.
Messinger, W., A. Liston, and K. Hummer. 1998. Ribes phylogeny as indicated by restriction-site polymorphisms of PCR-amplified chloroplast DNA. Plant Systematics and Evolution. In Press.
Rehder, A. 1954. Manual of cultivated trees and shrubs. 2nd ed. Macmillan: New York.
Sinnott, Q. P. 1985. A revision of Ribes L. subg. Grossularia (Mill.) per. Sect. Grossularia (Mill.) Nutt. (Grossulariaceae) in North America. Rhodora 87:189-286.
Tuinyla, V. and A. Lukosevicius. 1996. Pomology of Lithuania. Lithuanian Science and Encyclopedia Publisher; Vilnius Lietuva, Lithuania.
Vetenant,1799. Tableau du regne vegetal. J. Drisonnier, Paris.
Zielinski, Q. B. 1953. Chromosome numbers and meiotic studies in Ribes. Bot. Gaz. 114:265-274.
Vigor 1: 1=least, 3=most; Habit 11=spreading, 3=erect;
1Data collected at USDA-ARS National Clonal Germplasm Repository in Corvallis, Oregon.
2 Adapted from Brennan, 1996 and Tuinyla and Lukosevicius, 1996.