Microbial inoculants as plant growth stimulating and soil nutrient availability enhancing options for cucumber under protected cultivation
Protected cultivation of vegetables is often hampered by declining nutrient availability in soil due to year-around farming, which in turn, leads to poor quality and yields, causing serious concern. Our study aimed towards evaluating the potential of novel biofilm formulations—Anabaena or Trichoderma as matrices with Azotobacter sp. as Anabaena–Azotobacter (An–Az) and Trichoderma-Azotobacter (Tr–Az) or together as Anabaena–Trichoderma (An–Tr), on the growth, physiological activities, yield, and changes in the profiles of soil microbial communities in two cultivars (cv. DAPC-6 and cv. Kian) of cucumber (Cucumis sativus). Photosynthetic pigments, evaluated as an index of growth showed two–threefold increase, while elicited activity of defense and antioxidant enzymes was stimulated; this facilitated significant improvement in the plants belonging to the inoculated treatments. Microbial biomass carbon and polysaccharides in soil enhanced by two–threefolds in treatments receiving microbial formulations. Available N in soil increased by 50–90% in An–Az and An–Tr biofilm inoculated treatments, while the availability of P and organic C content of soil improved by 40–60%, over control. PCR-DGGE profiles generated revealed signification modulation of cyanobacterial communities and cultivar-specific differences. Significant enhancement in leaf chlorophyll pigments, soil microbiological parameters and nutrient bio-availabilities along with positive correlation among the analysed parameters, and distinct profiles generated by PCR-DGGE analyses illustrated the promise of these novel inoculants for cucumber.
KeywordsAntioxidant enzymes: biofilm Cyanobacteria Nutrients Protected cultivation Trichoderma
We are thankful to the Centre for Protected Cultivation Technology (CPCT), ICAR-IARI, New Delhi, for providing the facilities to conduct the experiment. We gratefully acknowledge the Division of Agronomy and Division of Microbiology, ICAR-IARI, New Delhi for providing necessary facilities for undertaking this study.
KS was responsible for undertaking the experimental analyses and writing the draft and its final formatting. AK helped in the biochemical and soil microbiological analyses. KR was responsible for the PCR-DGGE analyses. RP and BR developed the concept, coordinated the investigation and refined the manuscript. AKS was responsible for the experimental layout, its maintenance throughout the crop growth period and evaluation of yields. YSS helped in the analyses of soil nutrient parameters.
The study was partly funded by the AMAAS Network Project on Microorganisms, granted by ICAR to RP and the ICAR Extra Mural Research Project, granted to BR.
Compliance with ethical standards
Conflict of interest
The authors declare that the research work was conducted, without any commercial or financial relationships, which may be construed as potential conflicts of interest. We confirm that no part of this work has been submitted in any other journal and the authors have no conflict of interest. All the authors have consented to the submission of this manuscript. All data generated or analysed during this study are included in this published article [and its supplementary information files].
Human and animal rights
This study did not involve any human participants nor animal studies.
- Agritex (2011) Agritex horticulture management handbook volume 1. Causeway Harare, ZimbabweGoogle Scholar
- Anjanappa M, Venkatesh J, Kumara BS (2012) Influence of organic, inorganic and bio fertilizers on flowering, yield and yield attributes of cucumber (cv. Hassan Local) in open field condition. Karnataka J Agric Sci 25:493–497Google Scholar
- Antoun H, Pre´vost D (2005) Ecology of plant growth promoting rhizobacteria. In: Siddiqui ZA (ed) PGPR: biocontrol and biofertilization. Springer, Dordrecht, pp 1–38Google Scholar
- Bergmeyer N (1970) Methoden der enzymatischen analyse, vol 1. Akademie Verlag, Berlin, pp 636–647Google Scholar
- Hesse PR (1971) A textbook of soil chemical analysis. John Murray, LondonGoogle Scholar
- Isfahani FM, Besharati H (2012) Effect of biofertilizers on yield and yield components of cucumber. J Biol Earth Sci 201::83–92Google Scholar
- Kubicek CP, Mach RL, Peterbauer CK, Lorito M (2001) Trichoderma: from genes to biocontrol. J Plant Pathol 83:11–23Google Scholar
- Liang JG, Tao RX, Hao Z, Wang LP, Zhang X (2011) Induction of resistance in cucumber against seedling damping-off by plant growth-promoting rhizobacteria (PGPR) Bacillus megaterium strain L8. Afr J Biotechnol 10:6920–6927Google Scholar
- Mackinney G (1941) Absorption of light by chlorophyll solutions. J Biol Chem 140:329–342Google Scholar
- Mahmoud E, EL-Kader NA, Paul R, Akkal-Corfini N, El-Rahman LA (2009) Effects of different organic and inorganic fertilizers on cucumber yield and some soil properties. WJAS 5:408–414Google Scholar
- Manjunath M, Kanchan A, Ranjan K, Venkatachalam S, Prasanna R, Ramakrishnan B, Hossain F, Nain L, Shivay YS, Rai AB, Singh B (2016) Beneficial cyanobacteria and eubacteria synergistically enhance bio-availability of soil nutrients and yield of okra. Heliyon 2:e00066CrossRefPubMedPubMedCentralGoogle Scholar
- Nakano Y, Asada K (1981) Hydrogen Peroxide is scavenged by Ascorbate-specific Peroxidase in Spinach Chloroplasts. Plant Cell Physiol 22:867–880Google Scholar
- Olsen SR, Cole CV, Watanabe FS, Dean LA (1954) Estimation of available phosphorus in soils by extraction with sodium bicarbonate. US Dept Agric, Washington, DCGoogle Scholar
- Prasanna R, Sood A, Ratha SK, Singh PK (2014a) Cyanobacteria as a “green option” for sustainable agriculture. In: Sharma NK, Stal LJ, Rai AK, eds. Cyanobacteria: an economic perspective. Wiley, Chichester, pp 145–166Google Scholar
- Prasanna R, Kanchan A, Ramakrishnan B, Ranjan K, Venkatachalam S, Hossain F, Shivay YS, Krishnan P, Nain L (2016a) Cyanobacteria-based bio inoculants influence growth and yields by modulating the microbial communities favourably in the rhizospheres of maize hybrids. Eur J Soil Biol 75:15–23CrossRefGoogle Scholar
- Shao S, Tan SL, Li H (2016) Interactive effects of inoculated cucumber (Cucumis sativus L.) seedlings and saline soil. Commun Soil Sci Plant Anal 47:457–469Google Scholar
- Singh B, Sirohi NPS (2002) High-tech nursery raising technology for vegetables: a boon for vegetable growers. Indian Hort 47:22–24Google Scholar
- Subbiah BV, Asija GL (1956) A rapid procedure for the determination of available nitrogen in soils. Curr Sci 25:259–260Google Scholar
- Tan BZ, Bound SA, Eyles A (2017) Impact of management regimes on fruit quality of sweet cherry (Prunus avium L.). Agroecol Sust Food Syst 42:(493–503Google Scholar