Evaluation of protein content in a maize native race from Argentina
--V. R. Corcuera and C. A. Naranjo

With the purpose of incorporating germplasm of Argentine native races to a breeding program specially designed to improve the protein content of hard endosperm maizes, individuals of the race Pisingallo were evaluated.

The Pisingallo race has hard endosperm kernels that may be of different colors (white, red, yellow) and denotes a long evolutive cycle. The seeds of Pisingallo were collected at the location of Piedras Blancas in the province of Catamarca (Argentina) by A. M. Chiavarino and C. A. Naranjo during 1991.

Fifty ears were taken at random from the original population at Piedras Blancas, and a pedigree number was assigned to each one of them. Then, fifteen kernels were taken from each ear and were sown in a separate row. In each row, the best 2 or 4 plants were selfed and identified by a second number. The selfed ears (S1 lines) were harvested by hand and fifteen kernels were taken from each. Pericarp and germ were removed to evaluate endosperm protein content using microKjeldahl method (A.O.A.C., 1985) titrating with 0.025 N H2SO4.

The protein content values of each sample and replicates are shown in Table 1. In Table 2 the protein content range and average value for each pedigree may be seen.

Table 1. Average protein content for each ear evaluated.
 
Pedigree
Sample
Replicate
Average
1265/1
12.93%
12.70%
12.81%
1265/2
10.27%
9.83%
10.05%
1265/3
8.95%
9.17%
9.06%
1265/4
8.95%
8.73%
8.84%
1267/1
13.59%
14.25%
13.92%
1267/2
8.51%
8.51%
8.51%
1267/3
10.05%
11.16%
10.60%
1267/4
7.18%
8.06%
7.62%
1272/1
13.37%
12.04%
12.70%
1272/2
9.61%
9.39%
9.50%
1276/1
10.71%
11.38%
11.04%
1276/2
10.27%
10.71%
10.49%
1276/4
8.51%
8.06%
8.28%
1280/1
12.48%
12.92%
12.70%
1280/2
10.71%
11.38%
11.04%
1280/3
8.51%
9.17%
8.84%
1284/1
10.27%
9.83%
10.05%
1284/2
9.39%
10.05%
9.72%
1284/3
5.85%
4.97%
5.41%

Table 2. Protein content range for each pedigree studied.
 
Pedigree
 Minimun Maximun
1265 8.84% 12.81%
1267 7.62% 13.92%
1272 9.50% 12.70%
1276 8.28% 11.04%
1280 8.84% 12.70%
1284 5.41% 10.05%

Considering the nineteen selfed ears belonging to six pedigrees of the original Pisingallo population collected during 1991, it can be noted that the average endosperm protein content varies from 5.41 to 13.92%. This wide range, found for the trait in a Pisingallo maize population from Piedras Blancas, allows us to select ears with an uppermost protein content.

The next step will be applying the classic methodology of selection by high protein content to the following pedigrees: 1265/1 - 1272/1 - 1276/1 -1280/1 -1280/2 -1267/1 and 1267/3. 

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors

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