Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.47

MOLECULAR, BIOCHEMICAL AND AGRONOMICAL CHARACTERISATION OF TWENTY POPULATIONS OF ‘PEPERONE DI SENISE’ LANDRACE (CAPSICUM ANNUUM L.)

N. BASER*, G. SONNANTE **, G. LAGHETTI**, G. SARLI**, S. MOLINARI***, G. FANIZZA*

*) Dipartimento di Biologia e Chimica Agroforestale ed Ambientale; Sez. di Genetica e Miglioramento Genetico, Facoltà di Agraria di Bari

**) Istituto di Genetica Vegetale, C.N.R., Bari

***) Istituto per la Protezione delle Piante Sez. di Bari, C.N.R., Bari

characterization, ‘Peperone di Senise’, Capsicum annuum L., molecular markers, agronomical traits

In recent years, conventional agriculture and mechanisation, with the consequent aggression to the environment due to human activity, have caused a dangerous genetic erosion, that is a restriction of the variation of plant species and varieties. Such variation and the development of new local landraces are important resources of the agriculture in the world. As the increasing genetic erosion leads to the uniformity of the genetic background of cultivated crops, the availability of favourable wild genes is becoming crucial for plant breeding. Therefore, characterisation and evaluation of plant population collections stored at gene banks is useful to search for those genes which have adapted in natural conditions to resist pathogens or produce characters of high quality standards.

Because of international regulations for restriction of the use of artificial food stuffs, the interest in pepper as a condiment and natural colorant has steadily increased. Peppers are rich in carotenoids, which determine the colour of fruits and in the alkaloid capsaicin, giving the characteristic pungency. These two parameters of quality are genetically determined and influenced by environment. The “Peperone di Senise” pepper is the name of a landrace which has been cropped for many years and adapted very well in the Italian region of Basilicata. This landrace has been appointed as IGP by the European Union. In this paper, the agronomic traits of twenty populations of this landrace are reported along with the quality characters detected by a spectroscopic analysis of their content in colour and capsaicin; moreover, the genetic variability of this material has been tested by using RAPD markers. Agronomic traits were characterised using conventional morphological parameters from the whole plants, flowers, fruits and seeds. Qualitative analysis focussed on colour and pungency of fruits; the total extractable colour was assayed and expressed as ASTA international units per gram of paprika, while capsaicin as µg/g of paprika. DNA was extracted from a pool of leaves for each population and RAPD analysis was performed using 20 arbitrary decamer primers.

The twenty populations were characterized morphologically in detail in three locations of Basilicata region using 35 descriptors (from ‘Descriptors for Capsicum’ – IPGRI 1995). In general the results show a wide phenotypic homogeneity for the whole material even if some populations revealed distinguishing traits (e.g. pungency, fruit shape, corolla colour, growth habit, etc.). Interaction among different temperature and methods of drying with the capsaicin content (almost absent) and the ASTA value (positively correlated) were tested. In some cases (e.g. ‘Conte’, ‘Gazzaneo’, ‘Forte’ and ‘Amendolara’ populations) a different trend was recorded. These tests were carried out on fruits with and without seeds and peduncles. Concerning the yield, the best populations were ‘Forte’ and ‘MG12904’ with 23.9 and 22 t/ha of marketable fruits, respectively. The higher soluble solids content was reached by the ‘CVM’ population (8.8 %) while the lowest by the ‘CV1’ (5.8%).

In conclusion, thanks to the data from three locations and different years (to be completed in the next two years) these twenty populations will be sorted for yield, yield stability and homogeneity, and fruit quality. A considerable degree of variation was observed with RAPD markers. A UPGMA dendrogram based on Jaccard's similarity index allowed to cluster the populations according to their genetic affinities. Other molecular markers such as AFLP are being tested in this germplasm.