Tolerance to salinity of maize genotypes (Zea mays L.) during germination and early growth

Albena Pencheva, Gergana Desheva, Evgenia Valchinova, Svilena Tosheva

Abstract: The aim of the study was to assess the salt tolerance of three Bulgarian maize landraces (Zea mays L.) during germination and early seedling stage under seven levels of NaCl salinity (0, 25, 50, 75, 100, 125 and 150 mM) and also to find a relationship between salt stress and seedling growth. Increasing NaCl concentration caused a decrease in the germination percentage (G, %), the coefficient of velocity of germination (CVG, % day-1), the germination rate index (GRI) and the Timson germination index (TGI) and prolonged the mean germination time (MGT, day). Significant negative effects of salinity on shoot and root length, shoot and root fresh and dry weight of maize was found. Decrease in shoot length was more pronounced compared to roots for 73E840 and A9E0660, while for B5E0055 decrease in root length was more pronounced compared to shoot length. At the germination stage genotypes showed high to very high tolerance to the investigated salinity levels. At the highest salinity level (150 mM NaCl), A9E0660 was characterized as genotype with low tolerance to shoot growth, while 73E840 with medium and B5E0055 with high tolerance. B5E0055 showed low tolerance to root growth, while A9E0660 and 73E840 medium tolerance. In general, the investigated maize genotypes were significantly more tolerant to salt stress at germination than at early seedling growth stage. Linear regression analysis was implemented to find the relationship between salinity and studied germination and seedling characteristics and between germination and seedling characteristics.

Keywords: correlation; germination characteristics; linear regression; maize; salinity; seedling characteristics

Date published: 2022-12-16