Tolerance of cotton cultivars to water stress induced during seed germination

Abstract

There is a demand for cotton cultivars more tolerant of abiotic stress conditions, such as drought. This study assessed white and colored cotton genotypes for water stress induced during seed germination using polyethylene glycol 6000 (PEG). We evaluated three white cotton cultivars (UFUJP C, UFUJP T, and FM 966) and three colored cotton cultivars (UFUJP 5, UFUJP13, BRS Topázio), subjecting seeds to PEG-induced water stress at osmotic potentials -0.2, -0.4, and -0.6 MPa, during seed germination. The control plot (dose 0 of PEG) was performed for each genotype evaluated. We determined the dry matter of normal seedlings obtained in the germination test and performed the seed absorption curve in water and in PEG solution at -0.2 MPa. All cultivars evaluated showed a reduction in germination and imbibition speed when seeds were submitted to water stress. Cultivars FM 966 and BRS Topázio showed the highest tolerance. There was no difference between the groups of white and colored cotton genotypes for tolerance to water deficit. The better performance of the cultivars to tolerance did not reflect a higher imbibition speed of seeds.

Keywords

• gossypium hirsutum l.
• water deficit
• polyethylene glycol
• physiological potential