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2002
ABSTRACT
Composition and quantity of oil and protein in the seed are
influenced by the environment. Twenty seven cultivars, from the Maturity Groups III and
IV, were tested in three contrasting environments of the southern pampeana region of
Argentina. Average of protein and oil contents was 39, 3% and 22,7%; 39,9% and 22,7%;
42,4% and 20,3% for Balcarce I, II and III respectively. The content of linolenic acid
increased from 7,4% in Balcarce I to 9,1% in Balcarce III and that of oleic acid
diminished from 27,3% in Balcarce I to 25,5% in Balcarce III. It is possible to modify the
contents of oil, protein and fatty acids of soybean cultivars managing sowing dates,
provided that water stress is avoided.
Key words: soybean, oil,
protein, composition, quality, variability, environments
INTRODUCTION
Soybean (Glycine max L. Merr.) is
the most improtant oilseed crop in the world and in Argentina too. In this country, grain
and subproducts are exported mainly. In the southern pampeana region, south of latitude 36º S, the crop is grown on approximatly 100000 has with further
expansion expected. Cultivars of maturity Groups III and IV are well adapted to this zone.
Soybean grain is composed of proteins (40%), oils (20%), carbohydrates, fibers and aches.
The average protein and oil content in soybean, in Argentine, were 39,9% and 21%
respectively (Cuniberti and Pérez, 1995). The objectives of soybean breeding programs in
the world are geared towards the obtention of cultivars with specific contents of oil and
protein according to the demand of the markets. Soybean seed protein content and oil
content and composition are influenced by environment during seed development (Gibson and
Mullen, 1996). Oil and protein contents are negatively correlated (Burton, 1985) and the
protein content shows more variability than oil content (Weilenmann and Lúquez, 1999).
The objectives of this study were to observe 1) the effect of three different environments
on oil, protein and fatty acids contents of 27 cultivars of maturity Groups III and IV
sown in the southern pampeana region, and 2) the existence of variability for oil and
protein contents among these cultivars.
MATERIALS AND METHODS
Cultivars were sown in three environments: 1) Balcarce I,
normal sowing date (17/11/99) in dryland, 2) Balcarce II, normal sowing date (2/12/99)
with 155 mm of irrigation, and 3) Balcarce III, late sowing (7/1/00) with 115 mm of
irrigation. At all sites, soils were Argiudoll typical. The trials included 27 cultivars
supplied by different companies (Table 1). Each trial was arranged as a randomised block
design, with three replications. Plots were four rows wide at 0.7 or 0.35 m spacing and 5
m long and were sown at 23 seeds m-2 . Weeds were controlled by chemical and
mechanical methods according to the species present at each location. No insecticides or
fungicides were used. The two central rows of each plot were harvested in May 5 and June
20 and 29 at Balcarce I, II and III respectively. Protein and oil contents were measured
in two samples of 300g for each cultivar by near-infrared reflectance spectrophotometry.
Fatty acid contents (linolenic and oleic acids contents) were determined in a sample of
the oil of 11 cultivars ( P9492, Tj 2046, DM 3800, Joketa 46, P 9396, DM 4300, A 4456, DM
440, A 3205, ACA 490, and P 94B01) with a High Performance Liquid Chromatograph. Oil and
protein means were separated using the least significant difference test for those effects
having significant F-tests. Simple correlations (r) among means of oil and protein content
were calculated.
RESULTS AND DISCUSSION
Oil and protein contents average accross environments are
in Table 1.Average of protein content was 39, 3%, 39,9% and 42,4% for Balcarce I, II and
III respectively in the combined analysis of variance, which showed significant
differences between environments and cultivars and significant interaction genotype x
environment (P< 0.05). The percentage of proteins in Balcarce I ranged between 35,7
(HMS-41) and 41, 0% (P94B41), in Balcarce II between 36, 2 (A 3910) and 41,6% (P94B41),
and in Balcarce III it was 40, 9 ( DM 4000RR) and 44, 6% (A3205). Mean of oil percentage
was similar for Balcarce I and II (22,7%) and it was of 20, 3% for Balcarce III in the
combined analysis of the variance (cultivars with highest oil contents were DM 4000 RR, DM
43 and DM 48). There were differences between environments and cultivares (P< 0.05),
while the interaction genotype x environment was not significant. The content of linolenic
acid increased from 7,4% in Balcarce I (range between 4.66 for P 9396 and 8.67 for Joketa
46) to 9,1% in Balcarce III (range between 4.89 for DM 4300 and 11.02 for A 4456) and that
of oleic acid diminished from 27,3% in Balcarce I ( range between 35,23 for P 9326 and
21,45 for Tj 2046) to 25,5% in Balcarce III (range between 22,27 for A 4456 and 29,38 for
Joketa 46). Oil and proteins contents showed a negative correlation of -0.77 in the
combined analysis.
In our experiment, temperature during seed fill would be
the key environmental variable affecting grain quality characteristics, mainly oil content
and fatty acid profiles. This fact coincided with results of Kane et al. (1997).
Increasing seed-fill temperature (Balcarce I and II) elevated oil content and level of
oleic acid, but decreased protein content and level of linolenic acid. So, planting date
influenced protein and oil contents and fatty acid profiles, and soybean breeders could
target the development of lines with different protein and oil contents and oleic and
linolenic acids levels, managing planting date, provided that water stress is avoided.
Table 1. Protein and oil contents
in the grain of 27 soybean cultivars evaluated in three environments in the southern part
of Buenos Aires province, Argentina.
| Cultivars |
Seed company |
Protein content
(%) |
Oil content (%) |
| TJ 2046 |
BRETT S.A. |
40.44 |
22.21 |
| DM 48 |
DON MARIO S.A |
39.89 |
22.38 |
| FULGOR 33 |
JOSÉ BUCK S.A |
39.99 |
21.77 |
| P 9492 |
PIONEER S.A. |
41.10 |
21.87 |
| DM 4000 RR |
DON MARIO S.A. |
39.13 |
22.76 |
| A 4100 RG |
NIDERA S.A |
40.73 |
22.03 |
| TJ 2047 RR |
BRETT S.A. |
40.34 |
21.77 |
| A 4657 |
NIDERA S.A. |
41.24 |
21.80 |
| P 94B01 |
PIONEER S.A. |
41.93 |
21.91 |
| A 4501 RG |
NIDERA S.A. |
40.93 |
21.91 |
| DORADA 48 |
RELMÓ S.A. |
40.99 |
21.79 |
| JOKETA 46 |
NOVARTIS S.A. |
40.61 |
22.21 |
| P 94B41 |
PIONEER S.A. |
42.06 |
21.26 |
| A 4456 RG |
NIDERA S.A |
40.58 |
21.72 |
| A 4423 |
NIDERA S.A. |
40.67 |
21.83 |
| DM 440 |
DON MARIO S.A. |
39.66 |
22.20 |
| A 3205 |
NIDERA S.A. |
41.86 |
22.16 |
| A 3205 |
NIDERA S.A. |
41.86 |
22.16 |
| N MITCHELL |
PUBLIC |
41.60 |
21.79 |
| HMS-41 |
MONSANTO |
39.48 |
21.80 |
| P 9396 . |
PIONEER S.A |
39.86 |
22.23 |
| DELIA 46 |
RELMÓ S.A. |
39.21 |
22.23 |
| DM 4700 RR |
DON MARIO S.A. |
41.64 |
21.59 |
| DM 4300 RR |
DON MARIO S.A. |
41.13 |
21.69 |
| A 3910 |
NIDERA S.A. |
38.87 |
22.32 |
| BONAERENSE |
RELMÓ S.A. |
41.22 |
21.34 |
| DM 3800 RR |
DON MARIO S.A. |
40.42 |
22.29 |
| DM 43 |
DON MARIO S.A. |
39.83 |
22.38 |
| Mean |
|
40.57 |
21.97 |
REFERENCES
Burton, J.W. 1985. Breeding soybeans for improved protein quantity
and quality. In: Shibles, R. (ed.). World Soybean Research III. Proceedings. Westview
Press, Boulder and London.
Cuniberti, M. and Pérez, A. 1995. Calidad industrial de cultivares
de soja de grupo de madurez V corto, V largo, VI, y VII. : 47-53. Primer Congreso Nacional de Soja. Segunda Reunión
Nacional de Oleaginosos.
Gibson, L. and Mullen, R. 1996. Soybean seed composition under high
day and night growth temperatures. JAOCS, vol. 73, # 6: 733-737.
Kane, M.; Steele, C.; Grabau, L.; MacKown, Ch. and Hildebrand, D. 1997.
Early-maturing soybean cropping system: III. Protein and oil contents and oil
composition. Agron. J. 89: 464-469.
Weilenmann de Tau, M.E. and Lúquez, J. 1999. Variability of oil and
protein contents of commercial cultivars (group IV) in Argentina. Tests of
Agrochemicals and Cultivars # 20: 62-63.
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