Maize Genetics Cooperation Newsletter vol 84 2010
Please Note: Notes submitted to the Maize Genetics
Cooperation Newsletter may be cited only with consent of authors.
CRA-MAC
Unit� di Ricerca per la Maiscoltura
Via Stezzano 24, 24126 Bergamo
(Italy)
Valorisation of maize
genetic resources
Losa, A, Chitt�, A, Balconi, C, Motto, M, Redaelli, R
The continuous and significant loss of genetic
variability in crops has become a main concern in many countries. Several
researches were activated to maintain the existing variability and to identify
new sources to be exploited.
In Italy the Ministry of Agriculture, in
cooperation with CRA, funded in the past few years a project (Risorse Genetiche Vegetali, RGV) focused on the existing genetic resources
for most plant species (cereals, fruits, flowers, forest trees, forage species
and so on). The aims of this project were: i) to maintain
and regenerate the germplasm present in the CRA
structures, ii) to get a description of these materials from several points of
view (morphological, biochemical, genomic, and so on), and iii) to find a
possible valorisation and exploitation for the enlargement of the available
genetic variability and the development of new products with innovative
characteristics.
The genetic variability observed in Italian
maize germplasm was found to be quite large, and to
represent a good source of favourable alleles (Chitt�
et al., Maydica 45: 257-266, 2000; Hartings et al., Theor. Appl.
Genet. 117: 831-842, 2008; Berardo et al., J. Agric.
Food Chem., 57: 2378-2384, 2009). In the framework of RGV project, the activity
for maize was focused on the characterization of a set of inbreds,
collected and stored at the CRA- Maize Research Unit since the 1960s. These
materials had never been described before in terms of agronomic performance,
morphological parameters and chemical characteristics of the grain. In 2008,
about 600 inbreds, both from Italy and foreign
countries, were multiplied in the field, and the main descriptive parameters
were recorded: GDD for male and female, plant height and structure, number of
ears/plant and the height of their insertion point, leaf orientation, tassel
structure. On the basis of these observations, a group of 53 inbreds were considered interesting for being introduced in
breeding programs.
In 2009, the selected materials were multiplied
in the field, selfed, and crossed to a tester line
with good agronomic value. In parallel, a preliminary evaluation of their
susceptibility to fungal pathogens was carried out by kernel infection with Fusarium verticilloides.
After harvest, the ears� parameters were also collected. The future activity on
these materials will include their chemical characterisation by NIRS, the
dosage of mycotoxins in the infected ears, and the
realization of agronomic trials with the hybrid seed combinations.
Bio-fuels such as bio-ethanol are becoming an interesting alternative to fossil
fuels (Ragauskas et al., Science 311: 484-489, 2006).
The use of agricultural biomass for the production of bio-fuel has drawn
interest in many science and engineering disciplines. As one of the major
crops, maize offers promise in this regard: in fact, the rapidly expanding
information from genomics and genetics, combined with improved genetic
engineering technologies, offer a wide range of possibilities for enhanced bio-ethanol
production from maize (Torney et al., Curr. Opin. Biotechnol.
18: 193-199, 2007).
Two key parts of maize plants can be converted into bio-ethanol: the
kernel, which is mainly made of starch (Jobling, Curr. Opin. Plant
Biol. 7: 210-218, 2004), and the stover, which is
predominantly made of lignin and cellulosic components (cell wall) (Grabber,
Crop Sci 45: 820-831, 2005).
In 2009, 98 Italian and American maize inbreds
were sown in the field, and random crosses were made among them with purpose to
increase the genetic
variability.
About 278 hybrid combinations were selected; they will be tested in a
set of agronomic trials, in order to identify the most suitable genotypes, in
terms of kernel yield and plant biomass, to be exploited for bio-ethanol
production.