Maize Genetics Cooperation Newsletter vol 86
2012
MNLCORCUERA20121.DOC
CASTELAR, ARGENTINA
INSTITUTO DE GEN�TICA DR. E. A. FAVRET, CICVyA INTA
CASTELAR AND COMISI�N DE INVESTIGACIONES CIENT�FICAS
PCIA. BUENOS AIRES (C.I.C.)
Argentinean
High-Lysine and Modified Starch Corn Hybrids. II. Determination of the Grains Chemical Composition
by Near-Infrared
Corcuera V.R.1-3, Kandus M.2-3,
Salerno J.C.2-3
1. Com. Inv. Cient�f. Pcia. Bs. As. (C.I.C.) 2. INTA
3. Inst. Gen�tica Dr. Ewald A. Favret, CICVyA INTA Castelar.
The gross chemical composition of grains
yielded by single and double-crosses grown at the Instituto
de Gen�tica Dr. E.A. Favret
(IGEAF-INTA Castelar) during the growin
season 2010/11 was determined using an infrared spectrophotometer model Foss Infratec 1241 Grain Analyzer to quantify thru a
non-destructive assay protein content (%), starch content (%) and oil content
(%). The analysis was performed on two 60 g grain samples of each genotype obtained
by hand pollination to prevent contamination and xenia effect particularly on oil content. These results were
average to obtain the final values and come to complete others published
previously (see MNL83: 12-13, 2009).
Maize is the best energy source for animal dietary
rations. In average, corn kernel oil content is relatively low (3.0-5.0%) and
is mostly found in the germ. According to data published by ILSI and based on samples taken worldwide
(Source= ILSI Crop Composition Database version 2.0; www.cropcomposition.org)
corn oil content varies from 1.74 to 5.56%. Nevertheless,
MAIZAR (Argentine Maize Association) eventually
reported that the oil content measured by NIRT technology on 48 commercial hybrids
sampled within the limits of the ZMT and the southeastern
area of the province of Buenos Aires during the growing season 2004/05 NIR ranged
from 3.9 to 6.5%. High-oil content (HOC) corn shows up to twice the content of
this component and a higher protein quality than dent maize, so it also has a
greater energy value and may replace others high-cost fat and protein sources. According
to the U.S. Grain Council any genotype yielding grains with an oil content of �
6.0% should be considered as HOC.
Kernels protein content is highly
variable and depends mainly on the variety, sampling, production environment as
well as the calculation factors used to convert N into protein. In accordance
with ILSI Argentina, kernels average protein content is about 9.5% (when sampled 109 commercial hybrids grown in
the provinces of Cordoba and Buenos Aires between 1999 and 2001).
The gross chemical
composition of the grains produced by the single and double-crosses tested in
the experimental field of the IGEAF-INTA Castelar is
shown in Table 1. Average oil content was 5.3% (range=4.1 a 7.3%). Four crosses may be classified as HOC due to
their kernels oil concentration. The waxy
single-cross HC52 shows the kernels highest oil
concentration (7.3%) followed in decreasing order by the double mutant HC69 (6.2%),
the high-lysine single-cross HC57 (6.1%) and the double mutant HC59 (6.0%).
The average protein
content of the thirty hybrids tested was high (avg.= 12.2%; range= 10.8 to 13.6%). The double mutant HC59
yielded the highest protein content (13.6%) followed by the double mutants HC55
and HC95 which produce kernels with 13.3% protein. Also,
a high level of protein content (³ 12.0%) was detected in the grains of the genotypes HC49, HC50, HC57, HC58,
HC67, HC70, HC73, HC74, HC75, HC80, HC85 and HC92. In brief, eighteen out of
thirty hybrids yielded grains with more than 12.0% protein.
Finally, the average
content estimated for the thirty hybrids was 68.4% ranging from 66.7 to 69.9% (see Table 1). These values agree with those
detected by MAIZAR thru a NIR analysis of 48 commercial hybrids grown in the
main argentine corn area (ZMT) and southeast of the province of Buenos Aires
during the season 2004/05.
The single-crosses
HC57 and HC59 yielded kernels with both high protein and oil contents. These
results strengthen previous results obtained during the growing season 2009/2010 and are infrequent in improved
genotypes of this species.
Pearson�s
simple correlation coefficients among oil, protein and starch content were
calculated (see Table 2). The results
suggest negative and significant correlations between starch and oil protein
content (r= -0.45; p: 0.05), negative and highly
significant associations between starch and protein content (r= -0.48; p: 0.01) and once more, as in previous MNL reports, no significant
correlations between oil and protein content were found (r= -0.32; n.s.).
The results
of mean contrasts (tStudent) for the different chemical components
of the kernels of the groups of hybrids studied revealed that there are only
highly significant differences between DR and Flint hybrids for protein and
starch content (�t= 4.7 and 5.5
respectively; p: 0.01) as well as
between MS and Flint genotypes for kernels starch concentration (�t= 4.5; p: 0.01).
The kernels
oil content (6.0-7.3%) of the hybrids
HC52, HC57, HC59 and HC69 suggest that they could have competitive advantages
for animal feeding. Likewise, the oil and protein content found in these
experimental hybrids could be of special interest for animal nutrition and/or
the corn transformation industry.
Table 1= Gross chemical composition (via
NIRT) of thirty crosses tested in the experimental
field of the IGEAF- Castelar during the growing
season 2010/11.
|
HYBRID |
CROSS |
TYPE |
% OIL |
% PROTEIN |
% STARCH |
|
HC49 |
single |
MS (wxae1) |
4.8 |
12.0 |
69.2 |
|
HC50 |
single |
MS (wx) |
5.0 |
12.9 |
68.7 |
|
HC52 |
single |
MS (wx) |
7.3 |
10.8 |
66.7 |
|
HC55 |
single |
DR (wxo2o5) |
5.5 |
13.3 |
67.4 |
|
HC57 |
single |
HL (o2o5) |
6.1 |
12.1 |
67.0 |
|
HC58 |
single |
MS (wx) |
5.1 |
12.0 |
68.8 |
|
HC59 |
single |
DR (wxo2) |
6.0 |
13.6 |
67.4 |
|
HC66 |
doble |
DR (wxo2/Oh43) |
4.7 |
13.0 |
68.2 |
|
HC67 |
double |
DR (wxo2) |
5.1 |
12.3 |
68.2 |
|
HC69 |
double |
DR (wxo2) |
6.2 |
11.8 |
69.1 |
|
HC70 |
double |
DR (wxo2o5) |
5.1 |
12.5 |
68.0 |
|
HC72 |
double |
DR (wxo2/Oh43) |
5.0 |
13.0 |
68.4 |
|
HC73 |
double |
DR (wxo2) |
5.4 |
12.1 |
68.9 |
|
HC74 |
double |
DR(wxo2o5) |
5.4 |
12.8 |
67.3 |
|
HC75 |
double |
DR (wxo2) |
4.5 |
12.9 |
68.6 |
|
HC77 |
double |
DR (wxo2/Oh43) |
5.4 |
11.7 |
68.9 |
|
HC78 |
double |
DR (wxo2) |
5.4 |
11.7 |
68.6 |
|
HC80 |
double |
DR (wxo2) |
5.6 |
12.5 |
68.1 |
|
HC82 |
double |
DR (wxo2) |
5.5 |
13.1 |
67.2 |
|
HC83 |
double |
DR (wxo2/Oh43) |
5.4 |
11.9 |
68.3 |
|
HC85 |
double |
DR (wxo2o5) |
5.5 |
12.6 |
68.3 |
|
HC90 |
double |
MS(wxae1) |
4.1 |
11.8 |
69.1 |
|
HC91 |
double |
DR (wxo2) |
5.8 |
11.1 |
69.3 |
|
HC92 |
double |
MS (wx) |
5.6 |
12.9 |
67.3 |
|
HC93 |
double |
DR (wxo2o5) |
5.0 |
11.3 |
69.9 |
|
HC94 |
double |
MS (wx) |
5.0 |
11.6 |
69.0 |
|
HC95 |
double |
DR (wxae1) |
4.4 |
13.3 |
68.0 |
|
HC96 |
double |
DR (wxo2o5) |
5,6 |
11.7 |
69.0 |
|
HC97 |
double |
DR (wxo5) |
5.3 |
11.5 |
69.2 |
|
HC98 |
single |
MS (wx) |
5.6 |
11.4 |
68.7 |
|
ACA2000 |
single |
Flint or vitreous |
5.2 |
11.4 |
70.3 |
|
ACA
929 |
three-way |
Flint or vitreous |
4.9 |
11.6 |
69.8 |
Table 2= Pearson�s
correlation coefficients (r) among the different chemical components of the kernels determined thru
NIRT technology in experimental specialty corn hybrids grown in the IGEAF-CNIA
INTA Castelar (growing season 2010/11).
|
|
|
|
|
r |
|
Oil-Protein |
-0,32 n.s. |
|
Oil-Starch |
-0,45 * |
|
Protein-Starch |
-0,48 ** |
ns= non significant; *= significant at the level
of p� 0,05
**= significant at the level of p� 0,01
Please Note: Notes submitted to the Maize Genetics Cooperation
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