Growth promotion of the rice genotypes by pgprs isolated from rice rhizosphere

Abstract

Plant growth promoting rhizobacteria (PGPRs) improve growth of the host plants in a variety of ways. For this reason five bacterial strains isolated form the rice rhizospheric soil (B 15, B 17, B 19, BN 17 and BN 30) and three standard PGPR strains (viz. Pseudomonas putida, Pseudomonas fluorescens and Azospirillum lipoferum) were tested for plant growth promotion when applied to the rice plants as seedling treatments. The experiment was conducted for two rainy seasons of the years 2010 and 2011. Rice plants inoculated with the bacterial isolates recorded an improved plant growth and higher photosynthetic capacity signified by the higher chlorophyll content. Root and shoot dry mass was also found to be increased in the inoculated plants. Besides these iron and zinc content of the treated rice plants was also found to be higher in comparison with the uninoculated control plants. Hence, it can be concluded that application of PGPR has immense potential to be used as agricultural crop inoculants as they promote plant growth as well as improve the health and yield of the plants.

Assessment of Rice Associated Bacterial Ability to Enhance Rice Seed Germination and Rice Growth Promotion

“…The same results obtained from the experiment conducted by Mwajita et al (2013) in which over half of the bacterial phyllosphere isolates were able to solubilize phosphate, but generally the bacterial isolates from the rhizosphere and rhizoplane were more efficient in plant growth enhancement. The increase in shoot and root dry matter directly effects on the plant higher productivity 42 , which is clear in our results and the investigation of bacterial effects on rice yield at the end of growth season showed higher productivity than uninoculated control including tiller number, panicle number, the weight of 1000 grain and the number of full grain. It is evident that many different species colonize the tissues of the plants, but their persistence, activity and their interaction in this microbial community is not completely cleared.…”

“…Vegetative growth is an important growth phase in many crops as it determines the amount of biomass production and in rice it is important for development of tillers. A strong vegetative growth of rice plants reflects a higher plant height and greater plant biomass, larger number of tillers and panicles 42 . In current investigations, after seed germination experiment, more successful bacteria were selected for pot experiment to evaluate bacterial growth promoting effects on vegetative growth phase.…”

“…For each isolate 6 pots (replications) and for each pot, 3 seedlings were allocated. Before planting, rice seedling roots were dipped and shaken in selected rhizobacterial suspension (the bacteria isolated from rice rhizosphere) with a population density of 10 6 to 10 7 cfu/ml for one hour in 150 rpm to let bacteria colonize roots (Sharma et al 2014) and the phyllosphere spraying of bacterial suspension (the epiphytic and endophyte bacteria isolated from rice leaf and stem) was done after planting for epiphyte and endophyte bacterial colonization. Sprayed inoculated seedlings were wrapped up with plastic bags for 24 hours to make a humid condition for better colonization of bacteria.…”

“…Thus, recently, microorganisms as an inoculants to reduce the use of chemicals are being a matter of interest 13 . For stimulating rice seed germination and rice growth promotion biologically, there are many attempts to find successful bacteria 3,5,21,42 . Rice seed priming with plant growth promoting bacteria (PGPB), as an alternative for chemicals, can be considered to enhance seed germination, vigor index and germination speed 11 .…”

Comparison of chlorophyll content in greenhouse tomato and cucumber leaves after HBED-Fe and EDDHA-Fe applications

“…In fact, the primary response of a higher plant exposed to iron deficiency is the loss of chlorophyll, leading to poorer photosynthetic ability . The presence of a linear relationship between the iron content and the chlorophyll levels produced by the leaf (Yoshida 1981;Sharma et al 2014) allowed us to use chlorophyll measurements as a comparative parameter to study the difference between the modules.…”