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

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