CORN

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SEED QUALITY OF MAIZE INBRED LINES WITH
DIFFERENT OIL AND PROTEIN CONTENTS AND GENETIC
BACKGROUND.
Miriam Munamava, Susana Goggi and Linda Pollak
Iowa State University and USDA-ARS
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Background

• Corn breeding program crossing and selecting for
  oil and protein.
• Stiff Stalk crossed with germplasm from
  Argentina.
• Non- Stiff Stalk crossed with germplasm from St.
  Croix.
• Developed lines of different oil and protein
  content.

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Objectives

• To characterize the inbred lines for seed
  quality.
• To evaluate the effect of oil and protein levels
  on seed quality.
• To evaluate the effect of genetic background and
  production location on seed quality.

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Material and Methods

• Seed production
• Ames-IA
• Clinton-IL
• Colombia-MO
• Hooper-NE
• Starkville-MS

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Table 1 Description of Germplasm used in the Study
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Standard Germination Test
Planting on Paper towels
Seedling evaluations
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Saturated Cold Test
Seeds planting
Saturated cold test
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Electrical Conductivity Test

• Leakage of electrolytes amino acids and organic
  acids.
• Poor membrane integrity in deteriorated, low
  vigor seeds.

e-
e-
e-
e-
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EC

• Imbibe seeds in deionized water for 24 hs at 25o
  C
• Individual Seed Analyzer

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AA Test

• Increased temperature
• Temperature 42o C for 96h
• High relative humidity
• Planting
• Over CCP covered with sand

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Other Tests

• Soak test
• Fast green (FG)
• 100 seed weight
• Inbred quality index (IQI)
• SCAAFGSoak 200- (EC6hEC24h)
• 60

IQI
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Results and Discussion
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Table 2. Levels of significance from ANOVA for
ten maize inbred lines evaluated in four
locations.
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Table 3. Seed vigor tests comparisons between
groups of lines bulked by exotic genetic
background, Argentina (AR) and St. Croix (SC),
and seed composition, high oil (HO), low oil
(LO).
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Table 6 . Means electrical conductivity results
(24h).

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Table 8. IQI and relative ranking of the inbred
lines.

IQI
Ranking
5.4

1 HP

9

6.3

2 HP

5

3 HP

6.5

3

6.3

4 HP

5

5.0

5 HO

10

6 HO

6.3

5

6.6

7 HO

4

5.9

8 LO

8

9 B73

7.7

1

10 MO17

7.2

2

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Conclusions

• Low protein lines have the lowest seed vigor.
  When protein levels were high, seed quality was
  high regardless of oil content.
• Mo17 and B73 have the highest IQI. Inbred Quality
  Index results suggests that seed quality
  attributes should be considered in a
  comprehensive breeding program.
• Inbred line 4 (high protein) has the highest
  vigor when produced in IA and NE.

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Conclusions

• Inbred lines with Argentina germplasm have the
  highest seed quality.
• Seeds produced in IL have the best quality, while
  those produced in MO have the lowest quality.

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Acknowledgements

• Tom Hoegemeyer- NE
• Kevin Montgomery- IL
• David Willmot - MO
• Paul Williams- MS
• Penny Meyerholz
• Phillip Dixon (ISU Stats)