Physiological Quality of Malpighia emarginata D.C. Seeds Submitted to Salt Stress

Aims: The present experiment aimed to study the germinability of Malpighia emarginata D.C. seeds and initial growth under different levels of salinity stress.

Study Design: Completely randomised design.

Place and Duration of Study: Federal Institute of Education, Science and Technology of Ceara (IFCE), between February and April 2018.

Methodology: Acerola seeds of "Junko" cultivar were sown on germination paper imbibed with different concentrations of NaCl solutions, with osmotic potentials corresponding to 0, -0.3, -0.6; -0.9; and -1.2 MPa. The experimental design was completely randomised, with four replicates of 50 seeds. After sowing, the papers were rolled and stored in plastic bags, to decrease the rate of evapotranspiration, and they were kept at room temperature for 30 days. The following parameters were evaluated: initial germination percentage (IG%), final germination percentage (FG%), percentage of normal and abnormal seedlings, germination speed index (GSI), average germination time (AGT), shoot length (SL), root length (RL) and number of secondary roots (SR).

Results: The results of analysis of variance allowed verifying significant differences (P < .001) for the treatments in almost all the evaluated parameters, except for shoot length (SL). The increase of the salinity level inhibited germination and initial growth. The most significant reductions were at osmotic potentials lower than -0.6 MPa, being the development of root system more affected than aerial part of the seedlings.

Conclusion: The results of the initial germination and growth test showed that the "Junko" cultivar of acerola can be considered moderately tolerant to salinity in germination and initial growth phases.