LAXMAN, R.H.SOUMYA, PATIL2023-01-122023-01-122020-11-24Th-12736https://krishikosh.egranth.ac.in/handle/1/5810191970Tomato belonging to family Solanaceae is cultivated across the world. It requires in quite high quantity for growth and development. Phosphorus (P) being important macronutrient is involved in photosynthesis, respiration, energy generation and nucleic acid biosynthesis. Availability of P is one of the major constraints limiting productivity, due to its fixation and binding with other elements in the soil. Plants have adapted throughmodifications in root morphology, increased organic acids exudation and acid phosphatase activity to utilize bound P. Identification of genotypes having higher P acquisition and use efficiency is highly desirable under P limiting conditions. Hence, twenty-one tomato genotypes and its wild relatives were evaluated under P sufficient and deficient conditions. Based on phosphorus acquisition efficiency (PAE) ten contrasting genotypes were selected for further study and were grown in quartz sand supplemented with modified Hoagland solution to supply two levels of P. The root length, root volume, root P content, root-shoot ratio and activity of acid phosphatase were higher under low P supply and use efficiency was higher in high P supply. The genotypes, Arka Samrat, PKM-1, Solanum arcanum, Solanum galapagense, Solanum pimpinellifolium and Solanum peruvianum with better root characteristics, plant height, total plant P content were superior. They also had higher photosynthetic rate, stomatal conductance, transpiration rate, PSII yield and chlorophyll content. Thus, exhibited better performance under low P supply condition with higher P use efficiency.EnglishThesis