Physiological Characterization of Tripidium arundinaceum and Sugarcane (Saccharum spp.) Germplasm for Salinity Stress Tolerance at the Formative Stage

A total of sixteen accessions of Tripidium arundinaceum (Retz.) Welker, Voronts. & E.A. Kellogg (previously known as Erianthus arundinaceus (Retz.) Jeswiet) were evaluated for salinity tolerance at the bud germination stage by irrigating with 175 mM salinized Hoagland solution in perlite-sand hydroponics. Six accessions, IND99-907, IND01-1134, IND01-1136, IK76-48, and Bethuadahari, were germinated with healthy roots as compared to other accessions. These six accessions were further evaluated for morphological, physiological, and root anatomical parameters for different levels of salinity stress at the formative phase. Young leaf elongation was ceased after the fourth and twelfth day in Co 97010 and Co 86032, respectively, at 175 mM of salinity stress. The growth of young leaves in Co 97010 and Co 86032 was observed up to 25 mM of salinity stress only, whereas in T. arundinaceum accessions viz., IND99-907 and Bethuadahari, growth was recorded even at 175 mM. Lignification of cell walls, thickening of protoxylems, and vacuolization of cortex regions were observed in Co 97010, Co 86032, Bethuadahari, and IND01-1134 as compared to the normal anatomical structures in IND99-907. The accession IND99-907 recorded the lowest Na/K ratio, followed by IND99-1136 at 175 mM of salinity stress. The accession IND99-907 was identified as a salinity-tolerant genotype and suitable for utilization in the sugarcane crop improvement programmes.