~ 2920 ~ Journal of Pharmacognosy and Phytochemistry 2020; 9(5): 2920-2923 E-ISSN: 2278-4136 P-ISSN: 2349-8234 www.phytojournal.com JPP 2020; 9(5): 2920-2923 Received: 04-07-2020 Accepted: 09-08-2020 Aswathy JC Department of Agronomy, Kerala Agricultural University, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, India P Shalini Pillai Department of Agronomy, Kerala Agricultural University, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, India Jacob John Kerala Agricultural University, Integrated Farming System Research Station, Karamana, Thiruvananthapuram, Kerala, India KS Meenakumari Department of Agricultural Microbiology, Kerala Agricultural University, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, India Corresponding Author: Aswathy JC Department of Agronomy, Kerala Agricultural University, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, India Physiological parameters of rice ( Oryza sativa L.) as influenced by pink pigmented facultative methylotrophs (PPFM) Aswathy JC, P Shalini Pillai, Jacob John, KS Meenakumari Abstract A field experiment was conducted to assess the effect of PPFM on the growth of aerobic rice, at Integrated Farming System Research Station, Karamana, Thiruvananthapuram, Kerala, during summer, 2019 -2020 with the medium duration rice variety MO16 (Uma). The experiment was laid out in factorial randomised block design with [(5 x 2) + 2] treatments replicated thrice. The treatments comprised of five promising isolates of PPFM (P) obtained from the Department of Agricultural Microbiology, College of Agriculture, Vellayani, two methods of application (M) compared against two controls (C). The physiological parameters viz. chlorophyll content and proline accumulation had positive effect on application PPFM. The isolate PPFM 38 resulted in higher chlorophyll content and proline accumulation at both panicle initiation stages. Method of application did not show any significant difference in the chlorophyll content of rice whereas, the proline accumulation was found to be significantly higher with seed treatment with PPFM 38. The combined effect of PPFM and method of application was observed to be superior for the above mentioned physiological parameters significantly higher content at p5m2 both at panicle initiation and flowering stages. Keywords: Pink pigmented facultative methylotroph, chlorophyll, proline Introduction Rice is the most extensively consumed staple food of more than half of the world’s population, providing 21 per cent of global human per capita energy and 15 per cent of per capita protein (Khush, 2005). In the world, rice (Oryza sativa L.) is one of the most important field crops that provide staple food to millions after wheat. It is considered as an indispensable source of calories for majority of the population within Asia. Asia which is the native of 60 per cent of Earth’s population produces and consumes about 90 per cent of the rice in the world. Rice occupies an area of 167.13 m ha with a production of 782 million tonnes, covering all continents except Antarctica (FAOSTAT, 2018) [4] . Plants are subjected to several harsh environmental stresses like drought, salinity, low and high temperatures, flood, pollutants, and radiation adversely affect growth, metabolism, and yield and ultimately the productivity of crops (Lawlor, 2002) [12] . Enhancing rice production assumes paramount importance despite the constraints and challenges faced by the rice farmers. India ranks first in area and production among all the rice growing countries in the world next to China. In India rice alone is cultivated in 43.9 m ha with production of around 110.15 million tonnes and a productivity of 2.50 t ha -1 (GOI, 2016) [5] . Though being the largest producer in rice, the productivity is the lowest among the developing countries which need to be improved. India alone would need about 122 million tonnes of rice for domestic consumption. Among cereal crops, rice consumes about 80 per cent of the total irrigated fresh water resources. The rice production in Asia has declined due to increasing water stress (Tao et al., 2004). In ecologically sustainable agricultural systems, the bacterial inoculants that provide cross protection against both biotic and abiotic stress would be extremely desirable (van Loon et al., 1998) [19] . Proline is one of the most important amino acids, which occur widely in higher plants that accumulates in large quantities normally in response to environmental stress. The concentration of proline has been shown to be generally higher in stress-tolerant than in stress- sensitive plants and the accumulation is mainly correlated with stress tolerance. It has been suggested by Madhusudhan et al. (2002) [14] that under conditions of water stress accumulation of proline contributes to maintain proper balance between extra and intra-cellular osmolarity. Proline serves as a compatible solute and a protective agent for cytoplasmic enzymes and structures.