1. Evaluation of analytical methods for the assessment of seed
physiological quality (vigor) for predicting field performance,
seed storability and physical damages during harvesting or
conditioning.
2. Investigation on the role of mechanisms of detoxification and
protection from oxidative stress against seed deterioration.
3. Evaluate possible applications of molecular tools for the
assessment of Distinctness, Uniformity and Stability (DUS) and for
the identification of Essentially Derived Varieties (EDVs).
4. Development and evaluation of analytical methods for the
detection and quantification of genetically modified organisms
(GMOs) in conventional seed lots.
5. Development and evaluation of analytical methods for the
assessment of trait purity in biotech varieties.
6. Development of high throughput analytical procedures for the
assessment of varietal identity and purity, for traceability, and
for marker-assisted selection (MAS).
1. Early sowing is a widely adopted for spring crops, in
particular for maize, and requires the use of high vigour seed in
order to guarantee a rapid and uniform emergence. In other species,
aprticularly in vegetable crops, rapid and syncronous germination
is required for the production of transplants. Moreover many
manipulations of the seed after harvest can produce even severe
damages, with seed deterioration occurring thereof. The seed
industry requires analytical methods capable of predicting seed
performance in different sowing conditions and that can provide
information on physiological seed quality. This research is aimed
at identifying the most suitable methods for the evaluation of seed
vigour in maize and in other crops, in particular in horticultural
species. For the latter species we are evaluating the applicability
of some of these vigour tests to assess mechanical damages produced
on seed by harvesting and conditioning operations.
2. Investigation on the role of mechanisms of detoxification and
protection from oxidative stress against seed deterioration. During
storage, orthodox dry seeds progressively loose their viability due
to various structural and biochemical alterations, such as loss of
membrane integrity and impairment of proteins and nucleic acids.
Accumulation of free radicals (Reactive Oxygen Species, ROS),
associated with a decrease in the efficiency of the antioxidant
defence system, is considered as the main cause involved of seed
deterioration processes. Late Embryogenesis Abundant (LEA) proteins
are involved in the protection of cellular structure and
macromolecules conformation, thus helping the seed to withstand
damages that can occur both during dry storage and rehydration
process. Other mechanisms entail the repair of deterioration damage
to macromoleculaes, in particular to DNA and proteins. The aim of
this research work is to conduct a genetic and
physiological characterisation on a collection of sunflower
genotypes that could help to elucidate some of the mechanisms
underlying tolerance to seed deterioration..
3. In the EU, order to be commercialized, plant varieties must
be included in national lists. For this aim, as well as for to be
eligible of intellectual protection at the national or community
levels, they must be proved distinct, uniform and stable (DUS).
Thes prerequisites are currently assessed by means of two-year
field trials in which morpho-physiological traits identified by the
Community Plant Variety Office are evaluated.The main limits of
this system are: the high costs of field trials, the difficulties
in assessing distinctness based on morphology (different varieties
deemed as the same, and accessions of the same variety deemed as
distinct), the long testing time, and a certain degree of
inefficiency which do not allow a sufficient protection of both the
seed user as well as of the breeder. Regarding this latter aspect,
in particular, modern technologies (mutagenesis, marker-assisted
backcrossing, genetic engineering) allows the rapid development of
derived varieties that are barely distinct, at the morphological
leve, from pre-existing varieties, but that are practically
identical at the genetic level (essentially derived varieties,
EDV). Molecular markers allow to accurately assess genetic
relationtships among varieties. This research is aimed at
evaluating the possible use of such markers in assessing DUS
requisites and to identify cases of putative essential
derivation.
4. In Europe, as well as in many third countries, the
unintentional (adventitious) presence (AP) of genetically modified
organisms (GMO) in food and feed is specifically regulated. Whereas
the presence of unauthorized events is basically sufficient to
cause withdrawal from the market, products containing authorized
GMO above 0.9% must be labeled as such, but can be commercialised
provided that it can be demonstrated that the contamination was
unintentional. For seeds there is not at the moment a specific
regulation concerning the AP in conventional seedlots, and
thresholds still need to be fixed. The application of these
regulations requires the availability of methods to detect,
identify and quantify the presence of genetically modified
materials. While bare detection is relatively simple, several
issues arise for quantification. A thorough evaluation of the
possible sources of variability in quantification, from sample
processing up to PCR analysis, can provide information useful to
design test procedures that produce precise and accurate estimates
of the GMO content.
5.Worldwide, the cultivation of transgenic plants exceeded 100
million hectares, mainly concentrated in the US, Argentina and
Brasil. Herbicide tolerance is the prevailing trait, with Roundup
Ready (glyphosate tolerant) soybean varieties being grown on about
half of the global biotech area. The use of this technology
requires seed with high trait purity (usually above 98%). For this
purpose seed companies carry out extensive quality checks,
consisting of bioassays, immunoassays or PCR applied to single
seeds. We have proposed a novel real time quantitative PCR-based
approach to test trait purity that can be applied to bulk samples.
This development required the characterization of the insertion
site of a transgene and the design of a method to test purity of
glyphosate tolerant soybean. In principle this approach could be
successfully applied to any transgenic event and could represent an
important tool in agricultural biotechnology.
6. In order to make the best use of the progresses achieved by
means of the traditional breeding procedures as well as of the most
innovative techniques it is necessary to have variety
identification systems that can be utilized in all the steps of the
food chain, from seeds to the final products. At themoment SSR
markers represent the tool of choice for variety ID, even though
the procedures for their analysis are rather laborious and
expensive. Therefore the need exists of analytical protocols that
can be routinely used also on trasformed products. Therefore we
have conducted a research program aimed at developing efficient
analytical methods for variety ID based on SSR in durum and bread
wheat, as well as in rice. In other species (sunflower, tomato,
melon and cucumber) these marker systems could be a useful tool to
assess purity in F1 varieties.
