PLS221

Asteraceae

Artichoke

Origin and Domestication

Related Species

Most important traits

Diseases.


 Globe Artichoke: List of references (slides)

Species: Cynara cardunculus var scolymus, Asteraceae, (Compositae)

2n=2x=34

Origin: Mediterranean region, where it was cultivated during the Roman Empire. Possible place of domestication is Sicily, 2000 years ago.

It is a rich source of vitamins B and C, inulin from the roots and antioxidants from the leaves such as the flavonoid luteolin and di-caffeoylquinic acids. Other compounds of interest are phenols (cynarine), and sesquiterpenoids. Pills from artichoke extracts used to treat hepatic, digestive and urinary disorders. Also reported to be antimutagenic and have strong antioxidant activity.

C. cardunculus var sylvestris, wild cardoon, is closely related to artichokes and produces fully fertile hybrids in nature with this crop. It is the probable ancestor of artichokes. Cultivated leafy cardoon classified as var. altitis. (Sonnante et al 2007b)

There are six other wild species with some genetic affinity to artichokes. The crosses are difficult to make and the hybrids have reduced fertility:

C. baetica

C. algarbiensis

C. syriaca

C. cornigera

C. sibthorpiana

C. humilis

All six species cross with cultivated artichoke. The artichoke world collection is found in Bari Italy.

The following groups can be distinguished:

1) Spinosi group: characterized by long sharp spines in leaves and bracts.

2) Violetti group: Early types with violet-colored heads.

3) Romaneschi group: Late types with large, spherical heads

4) Catanesi group: small, elongated heads producing continuously from fall to spring. 

Artichoke was introduced to US by French and Italian immigrants in the 19th century. The main area of cultivation is in Monterrey county in California, although now it has been expanded to the desert with annual types from botanical seed adapted to those conditions.

Artichoke is a perennial, cross pollinated mainly by bees. The inflorescence or flower head is formed by many fertile flowers, which open progressively from the outside to the center. The flowers are protandrus. The stigma is receptive 5-7 days after the pollen grains are released. It passes through the anther tube, but it does not get fertilized since it is not receptive at that time.

Each head produces a variable number of seeds, from 100 to 700 seeds, depending on the variety and environmental factors. Primary heads produce more seed than secondary or tertiary heads. Seed germination is impaired at temperatures higher than 25 C. Scarification of seed may be sometimes necessary to improve germination.

Selfing results in some inbreeding depression. Heterosis is quite high, reaching 81% higher yield than the parental lines in some crosses.

Bolting:

Artichokes are long day plants. Transition from vegetative to reproductive stage in seedlings depends on the interaction of the following factors: 1) plant development, being necessary to have 7 or 8 leaves. 2) Low temperature, depending on the variety, 7 to 13 C, and 3) Photoperiod, minimum of 10.5 hours.

Application of gibberelic acid is used to induce bolting and uniform head production in areas where bolting conditions are not met. This strategy works much better for seed propagated varieties.

cv. Green Globe, is the main variety grown in California and for that matter in the US. It is a composite of genotypes from an introduction from Europe by early immigrants in 1880 and is propagated asexually by suckers or root sections.

The fields replanted every 5 years due to the decline of the plants and virus accumulation.

Most of the present breeding activity is focused on the development of seed-planted artichokes. Ultimate goal is to create seed propagated populations with improved characteristics and uniformity.

In the past few years, the seed-planted variety `Imperial Star' has been created in California. It is quite uniform, but still needs further selection.

In France, Israel and the Netherlands desirable inbreds have been developed for creation of F1 hybrids. Some of these are now available.

Normal propagation is by stem cuttings with attached root sections.

Inheritance of important traits:

Spines: Non-spiny type (Sp) is dominant over spiny. Non-spiny types can be selected at seedling stage.

Head color: Two genes might be involved in anthocyanin pigmentation, resulting in purple or green heads. One locus determines anthocyanin production, the second one is a color inhibitor, which is also dominant. Additional modifiers might be present to account for intermediate types.

Male sterility: Three genes for nuclear male-sterility have been reported, ms1, ms2 and ms3.

Other traits: Yellow foliage is determined by recessive j, white flower by recessive b.

 

Head size and shape are most likely polygenic traits, as well as earliness, yield and bolting response.

Breeding objectives: The ideal plants must produce at least 5 buds of large size per plant, spherical to ovoid in shape, compact, with closed bracts.

Molecular markers: The use of these tools has been very limited for this crop.

Isozymes have been used to determine phylogenetic relationships between wild and cultivated artichoke species.

RAPD markers have been used to assess the genetic variability of a few varieties and breeding populations. Nine microsatellite loci have been reported by Acquadro et al, (2003).

Lenteri et al (2006) produced the first linkage map by crossing a spiny with non-spiny type. It consists of over 200 markers including AFLP, SSR and other PCR based markers. Sonnante et al (2009) has reported additional SSR markers.

M-AFLP and S-SAP markers available. The first combine SSR and AFLP, the second one retrotransposons ans AFLP (Acquadro et al 2006).

A reference map based on artichoke x cardoon have been produced by Portis et al (2009).

Use of molecular markers in germplasm conservation

Biotechnology: It has been aimed mostly to micropropagation procedures. This technique has been accomplished mostly from meristerms, cotyledons and leaves of in vitro grown plants. Also virus cleaning by meristem culture of shoots can be done for yield improvement. There are problems, however with regeneration and rooting.

Embryo rescue can save up to 5 months by culturing the embryos 20 days after pollination (Carvero & Cointry (2007).

There are a few reports on artichoke transformation with Agrobacterium tumefasciens and biolistic procedures.

There are no reports on haploid production by anther or microspore culture.

Diseases:

Verticillium wilt. Resistant varieties to this disease have been identified.

Artichoke latent virus: Resistance is only present in some of the wild species.

Pests:

Artichoke plume moth is major pest.

Aphids

Leafminers

Slugs and snails


Return to syllabus

 

Last modified, May 13th 2010

 

Carlos F Quiros, 1998