Performance of rice genotypes at different phosphorus levels on root morphological traits and plant enzyme activity through hydroponics based screening

Soil phosphorus (P) deficiency has emerged as one of the major limiting factors in rice production. The development and deployment of tolerant cultivars are one of the plausible approaches to combat low P-tolerance in rice. Thus, the study was carried out to identify P-stress-tolerant rice genotypes through nutrient solution culture. Based on this preview, a hydroponics experiment was conducted at Radio Isotope laboratory, Tamil Nadu Agricultural University, Coimbatore. The treatment comprised of fertilizer levels viz. 0, 2.5 and 10 ppm P and seven rice genotypes viz. TNRH -18, ADT- 47, CB08509, CB08504, AD07038, ASD -16 and AS06016. This lab experiment was laid out in completely randomized block design (CRBD) with three replications. The results revealed that under different phosphorus levels the rice genotypes viz. TNRH-180 registered higher root volume (1.07 cm3), root length (35.29 cm), total no. of roots per plant (33.53 nos.) and no. of lateral roots (15.02 nos.) and it was followed by CB08504. The plant enzymes viz. acid phosphatase activity was found to be superior in the rice genotype CB08509 under 0 ppm P level (4.41 µmol pNpp) at 30 days old seedlings. At higher P levels the plant enzyme activity was found to be lower. Regarding adenosine triphosphate enzyme, CB08504 and TNRH-180 registered higher activity in 30 & 60 days old seedlings. Farmers and breeders can prioritize these rice genotypes for cultivation in phosphorus deficient soil ecosystem. By utilizing phosphorus tolerant rice genotypes can reduce the amount of phosphorus fertilizer required, minimizing environmental impacts and reducing input costs.