Germination and Seedling Growth of Genotypes Crambe abyssinica Submitted to Water Deficit

Abstract

Determining drought tolerance in plants is an increasingly important feature due to the reduction of water resources, since water stress is one of the main environmental factors that limit agricultural growth and productivity. The objective of this study was to evaluate the tolerance of crambe (Crambe abyssinica Hochst) genotypes submitted to water stress induced by polyethylene glycol during germination and early growth of seedlings. A randomized block experimental design was used in a factorial scheme consisting of five crambe genotypes (FMS Brilhante, FMS CR 1203, 1307, 1312 and 1326) and five levels of osmotic potential [0.0 (control), -0.2, -0.4, -0.5 and -0.6 MPa] in five replicates of 40 seeds. Germination rate (%), normal seedling development (%), germination speed index, root and shoot length, total fresh matter, and water content of seedlings (%) were analyzed. Physiological quality of seeds and initial development of crambe genotypes was improved in the group submitted to Ψw = -0.2 MPa. Germination and vigor index of crambe seeds were hampered by reduction of the potential to -0.4 MPa. The genotype FMS CR 1203 was the most tolerant to water stress, whereas FMS CR 1307 and 1312 were the most sensitive, as corroborated by PCA.

Morphophysiological responses of Crambe abyssinica Hochst. lineages submitted to water deficit during flowering

“…The germination test was carried out with 40 seeds per sample and 5 Gerbox® plastic boxes (n = 5). The germination percentage (%G) was determined according to the criterion of radicle emission, and the germination speed index (GSI) was measured during 7 d according to Braga et al (2019), calculated as described by Maguire (1962) using the formulas: %G = (Ʃni/N) × 100 and GSI = (G1/N1) + (G2/N2) + ... (Gn/n), where: %Ggermination per centage (with radicle emission considered to be germination); Σni -total number of seeds germinated; N -number of seeds placed to germinate; GSI -germination speed index; G1, G2, Gn -number of seeds germinated on the first, second, and last day; N1, N2, and Nn -number of days since the first, second and last day of sowing.…”