Variability of grain color parameters among local maize cultivars in Azerbaijan

Background. Aleurone and pericarp pigments in maize grain are regulated by the content of anthocyanins, carotenoids, tocopherols, and their various combinations, which determines their nutraceutical and coloring properties. Searching for sources of natural dyes to replace synthetic ones becomes increasingly popular and contributes to the development of hybrid maize breeding for food and dye production.

Materials and methods. A comprehensive study of Azerbaijani germplasm was used to select 112 diverse maize accessions and evaluate them for grain color. There were 5 blocks of study, conducted in two agroclimatic zones (Zaqatala in 2013, and Baku in 2014). The grain color gamut parameters were analyzed in the CIELAB system using the luminance coordinates (L* = 0 for dark, and L* = 100 for bright). The a* coordinate denoted red/green, with +a* for red, and –a* for green, and the b* coordinate denoted yellow/blue, with +b* for yellow, and –b* for blue. The hue angle and color in the a*b* plane were also measured.

Results. Five clusters with a wide grain color diversity were identified during the study of local maize accessions. The color intensity variation in the studied set was within the range of 42.36–66.49, the red/green values within 5.32–15.93, the blue/yellow values within 18.07–44.40, the color values in the a*b* plane within 18.98–46.12, and the hue angle values within 62.50–80.14. The ranking of colors into 5 clusters showed that 96 were concentrated in the 1st cluster, with the color brightness value of 58.16, the red/green value (a*) of 10.45, and the blue/yellow value (b*) of 32.82. Besides, the color value in the a*b* plane was 34.48, and the hue in the a*b* plane was 72.41. Some correlations were found between grain color and morphometric characters, and grain biochemistry.

Conclusion. The Azerbaijani local maize collection exhibits a wide diversity for the inbreeding of lines with various grain colors, promising for hybrid maize breeding.

1. Aka-Kaçar Y., Kuden A.B., Çetiner S. Identification of varietal polymorphism in Ficus carica L. by RAPD (randomly amplified polymorphic DNA) markers. Acta Horticulturae. 2003;598:167-172. DOI: 10.17660/ActaHortic.2003.598.24

2. Beetsma J. The CIELAB system – the method to specify colors of coatings. ULTRUS Prospector Knowledge Center; 2024. Available from: https://www.ulprospector.com/knowledge/16423/pc-the-cielab-system-the-method-to-specifycolors-of-coatings/ [accessed Dec. 10, 2024].

3. Dumanovic J. Visokouljani kukuruz, potencijalni izvor ulja visoskog kvaliteta. Beograd-Zemun: Institut za kukuruz; 1995. [in Serbian]

4. Gouesnard B., Dallard J., Panouillé A., Boyat A. Classification of French maize populations based on morphological traits. Agronomie. 1997;17(9-10):491-498. DOI: 10.1051/agro:19970906

5. Goyanka J., Yadav M.C., Kumari J., Tiwari S., Kumar A. Phenotypic characterization reveals high extent of genetic variation in maize (Zea mays L.) landraces of North-Eastern and North-Western Himalayan Regions of India. Indian Journal of Plant Genetic Resources. 2021;34(3):389-403. DOI: 10.5958/0976-1926.2021.00032.2

6. JMP Statistical Discovery: [website]. Available from: https://www.jmp.com/en/home [accessed Dec. 09, 2024].

7. Kahriman F., Akgül M., Ölmez I., Egesel C.Ö. Variability in some quality and agronomic characters in a high oil maize population under selection. Journal of Agricultural Faculty of Gaziosmanpaşa University. 2017;34(3):228-236. [in Turkish] DOI: 10.13002/jafag4219

8. Kettler W., Wilker G., Binder M., Franz W., Gabel P., Gauss S., Hempelmann U., Hennin R. Colour technology of coatings. Hannover: Vincentz GmbH; 2016.

9. Kırca L. Hue açısı nedir? Excel’de Hue açısı nasıl hesaplanır? Levent Kırca (blog); 2020. [in Turkish] Available from: https://leventkirca.com.tr/hue-acisi-nedir-excelde-hueacisi-nasil-hesaplanir [accessed Dec. 10, 2024].

10. Kumari J., Kumar A., Singh T.P., Bhatt K.C., Mishra A.K., Semwal D.P. et al. Collection, evaluation and phenotypic diversity assessment of maize (Zea mays) germplasm from North Eastern Himalayan region. The Indian Journal of Agricultural Sciences. 2017;87(6):727-733. DOI: 10.56093/ijas.v87i6.70929

11. Kumari J., Sharma S.S., Jacob S.R., Sharma R.K., Jakhar P., Langyan S. et al. Phenotypic diversity of maize landraces from North-Western India and exploring their potentiality. Indian Journal of Plant Genetic Resources. 2024;37(2):1-13. DOI: 10.61949/0976-1926.2024.v37i02.00

12. Lao F., Sigurdson G.T., Giusti M.M. (2017). Health benefits of purple corn (Zea mays L.) phenolic compounds. Comprehensive Reviews in Food Science and Food Safety. 2017;16(2):234-246. DOI: 10.1111/1541-4337.12249

13. Mantel N. The detection of disease clustering and a generalized regression approach. Cancer Research. 1967;27(2):209-220.

14. Meteoblue: A Windy.com company. Simulated historical climate and weather data for Zaqatala: [website]. Available from: https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/zaqatala_azerbaijan_584596 [accessed Dec. 29, 2024].

15. Nelimor C., Badu-Apraku B., Nguetta S.P.A., Tetteh A.Y., Garcia Oliveira A.L. Phenotypic characterization of maize landraces from Sahel and Coastal West Africa reveals marked diversity and potential for genetic improvement. Journal of Crop Improvement. 2019;34:122-138. DOI: 10.1080/15427528.2019.1674760

16. Öktem A., Toprak A. Determination of yield and morphological characteristics of some dent corn (Zea mays L. indentata) genotypes in Çukurova conditions. Harran University Faculty of Agriculture Journal. 2013;17(4):15-24. [in Turkish]

17. Öz A., Kapar H., Dok M. Corn agriculture. Samsun: Black Sea Agricultural Research Institute; 2017.

18. Özdemir E., Sade B., Correlation of some of agro-morphological and physiological traits in maize inbred lines developed in Konya conditions. Anadolu Journal of Agricultural Sciences. 2019;34(1):73-77. DOI: 10.7161/omuanajas.466502

19. TEPGE yayin No: 390. Aralık: TEPGE; 2023. [in Turkish] UPOV. Guidelines for the conduct of tests for distinctness, uniformity and stability. Maize (Zea mays L.). Geneva: UPOV; 2009. Available from: https://www.upov.int/test_guidelines/en/fulltext_tgdocs.jsp?lang_code=EN&q=maize [accessed on Jun. 07, 2025].

20. Vartanli S., Emeklier H.Y. Determination of the yield and quality characteristics of hybrid maize varieties under Ankara conditions. Journal of Agricultural Sciences. 2007;13(3):195-202.

21. Wang H.W., Hu H.X., Song T.M., Chen S.J. Seed traits evaluation from long-term selection of kernel oil concentration in a high-oil maize population KYHO. Canadian Journal of Plant Science. 2012;92(5):857-866. DOI: 10.4141/cjps2011-247

22. Wei K., Zhang H., Xu X., Du H., Huang Y., Zhang Z. Evaluation of phenotype and genetic diversity of maize landraces from Hubei Province, Southwest China. Frontiers of Agriculture in China. 2009;3(4):374-382. DOI: 10.1007/s11703-009-0075-1