Germplasm collection, characterization and evaluation

• Potato
• Hemp
• Sugarbeet

1. Use of RAPD and AFLP markers for variety characterization in hemp, potato and sugarbeet
   AFLP characterization of natural population of Beta vulgaris ssp. maritima (sea beet) in Italy
   AFLP characterization of local ecotypes of tomato (Pomodorino)
   AFLP characterization of bean germplasm
2. Biodiversity

Use of RAPD and AFLP markers for variety characterization in hemp, potato and sugarbeet

Variety characterization.
Hemp, potato and sugarbeet are all allogamous species, but the varieties commonly used, and therefore the strategies needed to characterize them at the molecular level, are different.

Hemp is dioecios and therefore obligately outbred; varieties have a high degree of variability and heterozygosity. Varietal characterization can be done only applying to the molecular data set statistical analysis and examining a meaningful number of individual plants; the occurrence of several sex-specific markers, probably linked to the Y chromosome, further make varietal characterization at the molecular level a complex task.
RAPD markers have been used to study the genetic structure of hemp varieties , and to obtain DNA fragments associated with specific traits; these markers have been sequenced and transformed into sequence-characterized PCR markers.

Potato is also allogamous, but because the varieties are clones, no intra-varietal diversity is usually found. This has been convincingly confirmed by several molecular studies showing the unicity and stability of RFLP or AFLP patterns associated to a given potato variety.
Multi-locus RFLP have been used for the characterization of new potato varieties bred at ISCI and for the quantification of genomic variations observed in potatoes deriving from in vitro-induced tubers or regenerated from cell cultures.
At ISCI, a wide germplasm collection of potato is maintained, both as tubers or as in vitro stored plantlets .
This collection is composed of more than 300 varieties, clones and wild material. This collection has been partly characterized for morphological, agronomical, physiological and molecular traits.

Beta vulgaris is an economically important crop species in the Italian Northern plains. Several new varieties are released each year, and most of the seed is multiplied in Italy, in Veneto and Romagna regions. In these same areas, however, also natural and domesticated population of sea beet and weed beet exist, which can undergo unintended crossing with the cultivated material (bolting sugar beets or seed beets).
Sugar beet breeding lines and their reciprocal relationships can be determined by AFLP analysis . Sugarbeet varieties are hybrids, with some degree of variability within the varieties. AFLP analysis cannot therefore establish unique patterns for varieties, but it can be useful to identify the relatedness of materials under selection or to be used as parentals. ISCI equipment and facilities are available for custom-made AFLP analysis of such material.

Contacts:
Dr. Andrea Carboni, a.carboni@isci.it
Dr. Aniello Mainolfi, a.mainolfi@isci.it
Dr. Giuseppe Mandolino, g.mandolino@isci.it

Biodiversity

There is an increasing awareness that the biodiversity within natural populations of species and subspecies closely related to agriculturally important crops, like sugarbeet, needs to be monitored and preserved against erosion by human activities. Among these activities, there are unintended introduction of transgenes from the cultivated varieties or the erosion caused by the huge pollen pressure deriving from multiplication fields in the proximity of wild areas.

• Beta vulgaris ssp. maritima is the wild ancestor of all cultivated beets. In Italy, an important area where sea beets can be found is the Po delta; in this region, wild populations of sea beet endowed with important resistance traits (cercospora and rhizomania) are present. These traits were in the past exploited and introgressed in the cultivated gene pool. These natural populations appear therefore an important reservoir of genetic variation to be characterized and protected.
  
  
• Beta maritima wild populations of Po delta are presently under the threat of genetic erosion, especially due to the proximity of commercial seed multiplication fields , and the molecular marker-assisted monitoring of the changes of their consistency, number and genetic structure will provide informations on the effects of human activities on this important reservoir of agronomically important traits .
  
  
• Seed samples are collected for further studies by ISCI, but the final target is the maintainance in loco of the sea beet populations located in the endangered areas.

Contacts:
Dr. Piergiorgio Stevanato, isciro@tecna.it
Dr. Aniello Mainolfi, a.mainolfi@isci.it