1. 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

2. 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.

3. 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.

4. Material and Methods  Seed production Ames-IA Clinton-IL Colombia-MO Hooper-NE Starkville-MS

5. Table 1 Description of Germplasm used in the Study Entry Seed composition Genotype 1High proteinSC01:N1310-378-11-1-1-7-3-B 2High proteinSC01:N1310-378-11-1-1-4-4-B 3High proteinAR16035:S02-325-1-1-6-4-7-B 4High proteinAR16035:S02-325-1-1-6-6-11-B 5High oilSC01:N1310-338-31-6-2-1-6-B 6High oilAR16035:S02-325-1-1-6-6-3-B 7High oilAR16035:S02-325-1-1-6-3-13-B 8Low oilAR16035:S02-325-1-1-6-3-9-B 9 B73 10 MO17

6. Standard Germination Test Planting on Paper towelsSeedling evaluations

7. Saturated cold test Seeds planting Saturated Cold Test

8.  Leakage of electrolytes: amino acids and organic acids.  Poor membrane integrity in deteriorated, low vigor seeds. Electrical Conductivity Test e-e-e-e- e-e-e-e- e-e-e-e- e-e-e-e-

9. EC  Imbibe seeds in deionized water for 24 hs at 25 o C  Individual Seed Analyzer

10.  Increased temperature Temperature: 42 o C for 96h  High relative humidity  Planting: Over CCP covered with sand AA Test

11. Other Tests  Soak test  Fast green (FG)  100 seed weight  Inbred quality index (IQI) SC+AA+FG+Soak + [ 200- (EC6h+EC24h)] 60 IQI =

12. Results and Discussion

13. Table 2. Levels of significance from ANOVA for ten maize inbred lines evaluated in four locations. VariableInbredInbred*location Standard germination*** Cold test***** AA***** EC*** Soak test*** Seed weight***

14. 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). ContrastColdAAECSoak AR vs. SCns ** HO vs. LO*ns ** B73 vs. ARns MO17 vs. SCns ***

17. Table 6. Means electrical conductivity results (24h).

19. Table 8. IQI and relative ranking of the inbred lines. IQI Ranking 1 HP 5.4 9 2 HP 6.3 5 3 HP 6.5 3 4 HP 6.3 5 5 HO 5.0 10 6 HO 6.3 5 7 HO 6.6 4 8 LO 5.9 8 9 B73 7.7 1 10 MO17 7.2 2

20. 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.

21. 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.

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