**Fruit Germplasm Characterization: Genomics Approaches for the Valorisation of Genetic Diversity**

Innocenzo Muzzalupo1, Enzo Perri1 and Adriana Chiappetta2 *1Agricultural Research Council - Olive growing and oil industry research centre (CRA-OLI), Rende (CS) 2University of Calabria (UNICAL), Dep. of Ecology Arcavacata di Rende (CS) Italy* 

### **1. Introduction**

54 Genetic Diversity in Plants

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The introduction of modern varieties of staple crop in agriculture seem to lead to an overall decrease in genetic diversity, although within the released varieties themselves the data are inconsistent and no overall narrowing of the genetic base can be discerned. The situation regarding genetic erosion in landraces and crop wild relatives is equally complex. While many recent studies have confirmed that diversity in farmers' fields and protected areas has eroded, this is not universally the case.

Many reports expressed continuing concern over the extent of genetic vulnerability and the need for a greater deployment of diversity. However, better techniques and indicators are needed to monitor genetic diversity, to establish baselines and monitor trends.

In recent years, there is evidence of growing public awareness with regard to the importance of genetic diversity, both to meet increasing demands for greater dietary diversity, as well as to meet future production challenges. The increased environmental variability that is expected to result from climate change implies that in the future, farmers and plant breeders will need to be able to access an even wider range of plant genetic resources for food and agriculture than today.

The existing *ex situ* collections of fruit trees germplasm may valuably provide either a source of genes potentially useful as raw material in plant breeding, or plants directly valid for a sustainable production. With respect to the latter item, we refer to those local varieties that, having evolved for a very long period in a location, and having developed adaptative traits, well integrated with the environmental, agronomic, cultural and traditional features of the site and more or less recently have been replaced with new varieties. The requirements of modern agriculture, such as sustainability call for the cultivation of a wider range of diverse material that could better respond to the different aspects involved. Specifically, if it is necessary to obtain new varieties with a broader genetic base, capable of producing under diverse conditions and to respond to different stresses – *i.e.* pests, drought, low fertility of the soil etc. On the other hand, in some cases, the re-introduction of old local varieties and the safeguard of traditional farming systems and landscapes can be very profitable from an economic and socio-economic point of views. In general, the lack of information about plant genetic resources conserved have the effect of limiting the use that can be made of large existing collections, restricting the value and the usefulness of a collection even within the owning institute and among other potential users. Hence, assessing the traits of the germplasm conserved in a collection is an essential prerequisite to a proper and wide utilization of the plant material conserved and it is the first step toward a further definition of the roles that the varieties can play in sustainable production, through the direct use or in breeding programmes.

In the past few years, several studies based on comparative high throughput sequencing of plant transcriptomes have, indeed, allowed the identification of new gene functions, contaminant sequences from other organisms, alterations of gene expression in response to genotype, tissue or physiological changes, as well as large scale discovery of SNPs (Single Nucleotide Polymorphisms) in a number of model and non model species, such us maize, grapevine and eucalyptus (Costa *et al.*, 2010).

Among the cultivated plants, olive (*Olea europaea* L.) is the sixth most important oil crop in the world, presently spreading from the Mediterranean region of origin to new production areas, due to the beneficial nutritional properties of olive oil and to its high economic value. The Mediterranean basin is the traditional area of olive cultivation and has 95% of the olive orchards of the world. From the Mediterranean basin, olive cultivation is presently expanding into areas of Australia, South and North America (Argentina, Chile, United States) and South Africa.

It belongs to the family of Oleaceae, order of Lamiales, which includes about 10 families for a total of about 11,000 species. Members of this order are important sources of fragrances, essential oils and phenolics claiming for numerous health benefits, or providing valuable commercial products, such as wood or ornamentals. Information on the genome sequence and transcript profiles are completely lacking. Olive is a diploid species, predominantly allogamous. In spite of its economical importance and metabolic peculiarities, very few data are available on gene sequences controlling the main metabolic pathways.

In spite of its economical importance and metabolic peculiarities, very few data are available on gene sequences controlling the main metabolic pathways in olive. With regard to oil, a range of biochemical methods to study the traceability of olive oil has to be presented. In fact, the analysis of minor and major components present in olive oil represents a valuable tool for authentication purposes.

Food authenticity has become a focal point for producers, consumers and policy markers. The DNA based technology is gaining a great attention in the field of food authenticity. This technology makes use of molecular markers such as RAPD, AFLP and SSR more efficient and constitutes promising approach for variety characterization and oil traceability in olives.

In this contest, the acquisition of additional information on biochemical markers in olive represents a fundamental and indispensable step to preserve the main olive varieties and also to safeguard the minor genotypes, in order to avoid a loss of genetic diversity and offer an important genetic basis for future breeding programs.

the safeguard of traditional farming systems and landscapes can be very profitable from an economic and socio-economic point of views. In general, the lack of information about plant genetic resources conserved have the effect of limiting the use that can be made of large existing collections, restricting the value and the usefulness of a collection even within the owning institute and among other potential users. Hence, assessing the traits of the germplasm conserved in a collection is an essential prerequisite to a proper and wide utilization of the plant material conserved and it is the first step toward a further definition of the roles that the varieties can play in sustainable production, through the direct use or in

In the past few years, several studies based on comparative high throughput sequencing of plant transcriptomes have, indeed, allowed the identification of new gene functions, contaminant sequences from other organisms, alterations of gene expression in response to genotype, tissue or physiological changes, as well as large scale discovery of SNPs (Single Nucleotide Polymorphisms) in a number of model and non model species, such us maize,

Among the cultivated plants, olive (*Olea europaea* L.) is the sixth most important oil crop in the world, presently spreading from the Mediterranean region of origin to new production areas, due to the beneficial nutritional properties of olive oil and to its high economic value. The Mediterranean basin is the traditional area of olive cultivation and has 95% of the olive orchards of the world. From the Mediterranean basin, olive cultivation is presently expanding into areas of Australia, South and North America (Argentina, Chile, United

It belongs to the family of Oleaceae, order of Lamiales, which includes about 10 families for a total of about 11,000 species. Members of this order are important sources of fragrances, essential oils and phenolics claiming for numerous health benefits, or providing valuable commercial products, such as wood or ornamentals. Information on the genome sequence and transcript profiles are completely lacking. Olive is a diploid species, predominantly allogamous. In spite of its economical importance and metabolic peculiarities, very few data

In spite of its economical importance and metabolic peculiarities, very few data are available on gene sequences controlling the main metabolic pathways in olive. With regard to oil, a range of biochemical methods to study the traceability of olive oil has to be presented. In fact, the analysis of minor and major components present in olive oil represents a valuable

Food authenticity has become a focal point for producers, consumers and policy markers. The DNA based technology is gaining a great attention in the field of food authenticity. This technology makes use of molecular markers such as RAPD, AFLP and SSR more efficient and constitutes promising approach for variety characterization and oil

In this contest, the acquisition of additional information on biochemical markers in olive represents a fundamental and indispensable step to preserve the main olive varieties and also to safeguard the minor genotypes, in order to avoid a loss of genetic diversity and offer

are available on gene sequences controlling the main metabolic pathways.

an important genetic basis for future breeding programs.

breeding programmes.

States) and South Africa.

tool for authentication purposes.

traceability in olives.

grapevine and eucalyptus (Costa *et al.*, 2010).
