**Session IV -- Physiology, Ecology and Production -- Poster IV-7a\***

**Strength and Weakness of Covered and Naked Oat: Approaches and
Perspectives**

Igor G. Loskutov

N.I.Vavilov Institute of Plant Industry, 44, B.Morskaya str.,
St-Petersburg, Russia. <i.loskutov@vir.nw.ru>

Genetic resources of *Avena* L. are represented by 26 species---both
wild and cultivated ones, the latter divided into covered and naked
forms. Collecting, studying and utilization of landraces was at its peak
in the first half of the 20th century, while in the second half the
primacy passed over to wild species. The greatest diversity of oat
landraces is concentrated in the *ex situ* collections of Russia and the
United States, but that of wild species in the genebanks of Canada, USA,
UK and Russia. Comprehensive study of monogenic characters in wild
species helped to identify more than 90 alleles of resistance to crown
rust genes and 17 alleles of resistance to stem rust. Besides, genes
controlling resistance to major oat diseases were found in wild oats
(*A. pilosa, A. hirtula, A. ventricosa, A. prostrata,* *A. barbata,* *A.
magna, A. murphyi, A. macrostachyi, A. ludoviciana* and *A. fatua)* as
well as in landraces and cultivars belonging to cultivated species (*A.
strigosa*, *A. abyssinica,* *A. sativa* and *A. byzantina).* Dozens of
oat improved cultivars bred on their basis now occupy vast areas in all
the continents. Subsequent analysis of polygenic quality parameters of
kernels in wild species (*A. magna, A. murphyi, A. ludoviciana, A.
fatua* and *A. sterilis*), landraces and cultivars has shown that they
possess increased protein content and amino acids composition, fats and
fatty acids composition. Thus, they served as sources in recurrent
breeding programs for producing cultivars with high protein and oil
content.

Regretfully enough, today the search for new sources of quality
parameters goes on with less intensity that in the previous years and
ignores studying inter- and intraspecific diversity. Indeed, genetic
diversity is studied as far as the content of β-glucans, sterols,
tocopherols, avenanthramides and other quality character are concerned,
but mostly in improved oat cultivars. These activities succeeded to
identify plant forms with increased content of quality characters. They
are now used to develop functional, dietary and baby-oriented food as
well as to produce cosmetics and pharmaceuticals.

Scientists at the Vavilov Institute of Plant Industry performed
comparative study of a number of quality characters in wild oat species
and both covered and naked cultivars. This project resulted in selecting
high-protein forms of cultivated covered (17-18%) and naked oats
(18-19%). It was also discovered that covered oats have protein
composition different from naked ones, the latter containing
considerably less water-soluble proteins---albumins and globulins. Among
the accessions of wild species, plant forms with protein content above
20% (*A. pilosa, A. clauda, A. ventricosa, A. longiglumis, A.
canariensis*, *A. hirtula*, *A. strigosa, A. barbata*, *A. fatua* and
*A. sterilis*) and 30% (*A. magna* and *A. murphyi)* were identified*.*
When isolating forms with high oil content in cultivated covered (7-8%)
and naked (809%) oats, this parameter in wild population reached the
level of 10-11% (*A. ventricosa, A. clauda, A. pilosa, A. canariensis*,
*A. wiestii, A. magna*, *A. murphyi, A. fatua* and *A. sterilis*), while
the quality of oil in terms of oleic acid content (more than 40%) in
many accessions matched sunflower's. The content of β-glucans in covered
oat accessions on the average varied from 2.5% to 3.5%. However, a
number of varieties were identified for even higher levels (4.8-5.1%).
Evaluating a set of wild species showed that many accessions have
increased content of β-glucans (up to 6%) in grain. Analysis of
antioxidants in oat ascertained that total content of tocopherols
(vitamin E) in covered cultivars was 2-3.5 times lower than in naked
ones, which equaled soybean oil in this important antioxidant component.
In addition, naked cultivars contained up to 95% ά and β+γ fractions of
tocopherols. The content of sterols in covered (1.8-2.4%) and naked
(2.3-2.6%) oat cultivars was also different. It is known from
publications that the content of avenanthramides in naked cultivars is
2-4 times higher than in covered ones, but these data are not too
numerous.

Thus, populations of wild oat species, its interspecific and
intraspecific diversity demonstrate considerable variability in quality
parameters of kernels. Therefore, it seems expedient to continue and
even expand biochemical and genetic research involving the entire
botanic diversity of genus *Avena* L. It should be targeted at quality
characters to meet today's demands of conventional and other breeding
process as well as numerous processing industries.