NIR spectroscopy coupled with the multivariate calibration technique could be used to accurately measure the quality parameters of apples. In addition, in the case of breeding programs, NIR spectroscopy can be considered an interesting tool for sorting varieties according to a range of concentrations.

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Oxalis tuberosa is an important crop cultivated in the highest Andean zones. A germplasm collection is maintained ex situ by CIP, which has developed a morphological markers system to classify the accessions into morphotypes, i.e. groups of morphologically identical accessions. However, their genetic uniformity is currently unknown. The ISSR technique was used in two experiments to determine the relationships between both morphological and molecular markers systems. The intra-morphotype genetic diversity, the spatial structures of the diversity and the congruence between both markers systems were determined. In the first experience, 44 accessions representing five morphotypes, clearly distinct from each other, were analyzed. At the molecular level, the accessions exactly clustered according to their morphotypes. However, a genetic variability was observed inside each morphotype. In the second experiment, 34 accessions gradually differing from each other on morphological base were analyzed. The morphological clustering showed no geographical structure. On the opposite, the molecular analysis showed that the genetic structure was slightly related to the collection site. The correlation between both markers systems was weak but significant. The lack of perfect congruence between morphological and molecular data suggests that the morphological system may be useful for the morphotypes management but is not appropriate to study the genetic structure of the oca. The spatial structure of the genetic diversity can be related to the evolution of the species and the discordance between the morphological and molecular structures may result from similar selection pressures at different places leading to similar forms with a different genetic background.

BACKGROUND: Several studies have shown that cherries, especially sour cultivars, contain substantial amounts of phenolic compounds. OBJECTIVE: This study aims to (i) analyze the total phenolic compound (TPC) content and the antioxidant capacity (AC) of a large range of cultivars using the same methodology in one laboratory, and (ii) determine the possible relationship between agronomic characteristics and AC. METHODS: A total of 245 samples including sweet, sour and hybrid cultivars from our collections were harvested at their optimum maturity and characterized according to their TPC, DPPH and ORAC values. RESULTS: The TPC content and DPPH and ORAC values varied greatly among the cherries, with the sour cultivars presenting higher levels than the sweet ones. The PCA plot showed a slight grouping by species and confirmed the high TPC content level in sour cultivars. The bi-colored cultivars had lower TPC and antioxidant capacity (AC) values than dark-colored ones, indicating that coloration could give an indication of the AC of fruits. No significant relationship between the agronomic and chemical properties was highlighted. CONCLUSIONS: Cherry fruits, especially from sour cultivars, represent an important source of bioactive compounds and could attract new interest as a 'functional food'.

Mashua (Tropaeolum tuberosum) is a vegetatively propagated tuber crop cultivated in the Andes. This study aims to determine mashua's genetic diversity and structure, which have never been investigated until now. Sixty-eight accessions collected in nine departments of Peru were analyzed with 17 intersimple sequence repeat primers. Three multivariate analysis methods (multiple correspondence analysis, clustering analysis, and assignment method) were used to investigate the genetic structure of the species. A total of 193 reliable markers were generated, of which 169 (88%) were polymorphic. Except for four accessions, the results of the three methods were in perfect agreement. They established the existence of three groups of accessions corresponding to the northern, central, and southeastern regions of Peru and showed a genetic structure clearly influenced by geographical provenance. The average genetic distance over all the accessions (Jaccard's coefficient) showed a moderate level of diversity (0:35 6 0:05). It may be explained by the reproductive and farming characteristics of the species. The methodology used here to study mashua has revealed valuable and reliable information on its genetic diversity and structure, which should be investigated more extensively along the Andes to establish appropriate conservation strategies.

A preliminary study of the genetic diversity of Bolivian oca (Oxalis tuberosa Mol.) varieties maintained in situ and ex situ through the utilization of ISSR molecular markers Marie Malice AE Nicolas Martin AE Audrey Pissard AE Jorge A. Rojas-Beltran AE Antionio Gandarillas AE Pierre Bertin AE Jean-Pierre Baudoin Abstract ISSR molecular markers have been used to investigate genetic diversity of oca (Oxalis tuberosa Mol.), an Andean neglected tuber crop species. Sampling procedure allowed a preliminary study of the genetic diversity at the intra-and intervarietal levels. Twenty tuber lots conserved in situ in the microcentre of Candelaria and ex situ in the Toralapa Centre (Bolivia) were identified. Four ISSR primers amplified a total of 25 fragments of which 17 (68%) were polymorphic. These experiments show that the structure of oca varieties is mainly based upon vernacular names with a greater differentiation among tuber lots than within them, supporting agromorphological data. ISSR technique enlightened the existence of heterogeneous varieties in oca and divergence between in situ and ex situ conservation strategies. These observations are potentially linked to the different ways of management of tubers in these two conservation systems.

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