endophytic microbes to enhance brachiaria productivity in semi-arid environments of sub saharan...
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Presented by Sita R. Ghimire at the ILRI BioSciences Day, Nairobi, 27 November 2013TRANSCRIPT
Endophytic microbes to enhance Brachiaria productivity in semi-arid environments of
sub Saharan Africa
Sita R. Ghimire
ILRI BioSciences Day, Nairobi, 27 November 2013
Livestock in sub-Saharan Africa (SSA)
• Livelihood of 70% of the smallholder farmers
• Food sources, key inputs to crop production and income
• Reduces food security risks resulting from seasonal crop failures
• Low livestock productivity and negligible productivity growth over the past decades
• Shortage of forages – especially in dry season
Brachiaria grasses
Native • Native perennial grasses of East Africa
• Persistence to grazing
• Tolerant to drought, low pH and aluminum toxicity
• Can grow in marginal land
• High above ground biomass yield (30t DM/ha/yr.)
• Carbon sequestration (5t/ha/yr.)
• Enhance N use efficiency (through BNI) and minimize GHG
• Extensively grown across the world but NOT in native homeland - AFRICA
The problem: its significance
• Limited availability of forages is a major limitation of livestock production in SSA
• Climate smart Brachiaria Program
Increase availability of forage through (a) introduction of improved Brachiaria cultivars, (b) improvement of local ecotypes, (c) exploration and utilization of native endophytic microbes, and (d) capacity buildings.
• Promote native flora as an important forage species (SLO4), increase milk and meat production (SLO3 and SLO2), and increase income of farmers (SLO1).
Endophyte and plant associated microbes
“All those organisms inhabiting plant organs that at some time in their life, can colonize internal plant tissues without causing apparent harm to the host” (Petrini, 1991) • Protect against herbivores• Protect against abiotic stress• Produce plant growth-regulating substances• Enhance nutrients uptake and/or solubilization• Suppress or compete with disease-causing
microbes• Enhance biomass and grain yields
(Kelemu et al., 2001 ; Clay & Schardl, 2002; Schardl et al. 2004; Taghavi et al. 2009; Rodriguez et al. 2009; Ghimire & Craven, 2011, 2013)
Endophyte and forage grasses
(Tanaka et al. 2005)
E+E-
Persistence of Tall Fescue(N. coenophialum)
E+ E- ΔPer
Insect Resistance in Rye Grass(Neotyphodium lolii)
(Noble Foundation, OK, USA)
1
ENDO 5
Fig. 2 Effect of soil inoculation of two strains of Sebacina vermifera on the performance of switchgrass NF/GA-993 clonal seedlings six weeks after inoculation.
Endophyte and forage/bioenergy grass
Fig. 1 Effect of Sebacina vermifera inoculation on (a) above ground growth of switchgrass plants after 2 months of inoculation (b) and root growth after 7 months of inoculation
Ghimire et al. 2009 Ghimire & Craven 2013
Fig 3. Switchgrass seedlings after exposure to the mild drought stress. Co-cultivated seedling with Sebacina vermifera strain MAFF 305830 (left), with S. vermifera strain MAFF 305828 (middle) and mock-inoculated controls (right).
Table 2. Effect of Sebacina vermifera on switchgrass mean biomass yield under mild drought stress (means ±LSD)
65%
45%
(Ghimire & Craven 2011)
Endophyte and forage/bioenergy grass
Harman, 2011
Fig 4. Maize crop at the end of the season in the DRC-Africa from seed treated with beneficial fungi (right) and with out fungi (left)
Fig 5. Diagram of the overall effect of Trichoderma strains, and of other root colonizing plant symbiotic microbes on plants and plant productivity.
Endophyte and staple food crop
Har
man
, 201
1
Results – fungal endophyte
Total of 130 fungi, 57 identified - six Acremonium spp.
Fig 6. Phylogenetic relationships of endophytic fungi of Brachiaria
• Forty bacteria isolated, 18 identified - six genera including Herbaspirillum, Pantoea and Pseudomonas
• Microbial culture collection established with current inventory of 77 microbes
Fig 7. Phylogenetic relationships of endophytic bacteria of Brachiaria grasses
Results – bacterial endophyte
Research plot establishment
Brachiaria ecotypes collections Meta-genome analysisBiological nitrification inhibition (BNI) Variety evaluations (demo. plot)
Production of endophyte - free Brachiaria clones
Micro propagation Heat treatment
Results/progress
Conclusions and discussion points
• Identified endophytic fungi and bacteria of Brachiaria grasses that are potentially useful for plant growth promotions and adaptation to climate change effects.
• These microbes need multiple tests to determine their utility for agricultural applications.
• Characterization of microbes - needs collaborations
• Policy and regulatory supports
Where to from now?
• Characterization of microbes - biochemical, biological and plant growth promotion; meta-genome and BNI studies to determine role of Brachiaria on nutrient use efficiency and soil fertility
• Contribution to CGIAR System Level Outcomes - Promote native grasses (SLO4); increase forage availability then milk and meat (SLO2); improve nutrition and health (SLO3); increase income and reduce poverty (SLO1); and CRPs 3.7, 4 and 7.
• Collaboration with national partners and scientist abroad
Acknowledgements
Institutions
The presentation has a Creative Commons licence. You are free to re-use or distribute this work, provided credit is given to ILRI.
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