The effects of oligochitosans on the growth of in vitro rice seedlings under salinity stress

Seawater intrusion causes many unfavourable effects on crops, especially rice, which is very sensitive to salt. Salinity stress reduces the growth and development of rice, thereby reducing the yield. This is an important issue affecting the food security of many countries in the world. This study focused on using oligochitosans to increase salinity tolerance and improve rice growth at the seedling stage.

Dry and rice-sprouted seeds were treated with oligochitosan solutions of different molecular weights and concentrations and incubated in NaCl solution at a concentration of 0.6%. The salinity tolerance of rice seedlings was assessed through in vitro indices in the plants’ shoot length, number of leaves, number of roots (apical and lateral roots) and root length, fresh and dry weight, photosynthetic pigments, proline, total sugar and total protein.

Oligochitosan 5994 Da at a concentration of 75 ppm improved the growth of rice seedlings under salinity conditions. Oligochitosan 11126 Da at the concentration of 100 ppm improved the growth of rice seedlings under salinity stress in the investigation of dry seed treatment. The salinity tolerance of rice seedlings was observed through the increase of photosynthetic pigments, proline, and total sugar concentration and morphology.