1. Arbuscular Mycorrhizal Fungi (AMF) in the rhizosphere of bananas in farming systems of Central Kenya
Jefwa J.M., Vanlauwe B., Sanginga N. Elsen A., Kahangi E., van Asten P. Losenge, T., Mwajita M., Robinson. J and Ruto L
Banana plants in a Nutrient Omission trial in Maragua, Kenya manifesting
Introduction nutrient deficiency in low fertility soils.
Banana production in central province in Kenya (Maragua district) is estimated at
30t/ha/yr. In 2003, 3355ha of land was under banana with estimate production of
38,040tons with market value of US $ 4,322,727. Decline in soil fertility, pests and
diseases, inadequate water and lack of clean planting materials are major production
constraints. The main sources of planting materials are Tissue culture (TC) plantlets.
1. What are the Challenges
There are challenges in survival and establishment of tissue culture plants particularly
All fertilizer minus micronutrients All fertilizer minus K
in soils with production constraints. Use of rhizosphere organisms has great potential
to alleviate or minimize these constraints.
Banana is highly dependent on Mycorrhizae for its growth. The Arbuscular
Mycorrhizal fungi (AMF),fertilizer minusendophyte can enhance survival and establishment of
root P
All fertilizer minus P
All
All fertilizer minus P
TC plants under the banana fertilizer minus P
All production constraints. Commercial inoculum is
available. However, there are challenges on the effectiveness of the exotic AMF
species in new environmental conditions.
All fertilizer minus P
All fertilizer minus P
The range and average soil nutrient status of 50 farms and a nutrient omission trial
established at the same site.
Not all AMF species are effective on banana growth. Hence the use of Banana
rhizosphere AMF endophytes is the most appropriate. . The greenhouse trial
clearly indicated the importance of the symbiosis in nutrient absorption. In the
absence of effective AMF, bananas were not able to take up nutrients effectively.
AMF are crucial in nutrient Greenhouse Inoculation trial with commercial exotic
AMF species showed three Glomus species to be more effective on plant growth
parameters. In the absence of AMF, growth of banana plantlets was poor even with
Hewitt nutrient solution.
10 2.5 300
9
S h o o t d r y w e ig h t ( g )
P la n t h e ig h t ( c m )
8 2 250
L e a f s u r fa c e a r e a
7
6 1.5 200
5
150
4 1
3 100
2 0.5
1 50
0 0 0
None Gi albida G. G. G. mosseae None Gi albida G. G. G. mosseae None Gi albida G. G. G. mosseae
etunicatum intraradices etunicatum intraradices etunicatum intraradices
AMF treatments AMF treatments AMF Treatments
Tissue cultue banana plantlet
All fertilizer minus micronutrients
All fertilizer minus P
devoid of corm and few root
systems. AMF increase the
All fertilizer
root surface area and
explores fro nutrients beyond Photograph:
1-Control; 2- Gigaspora albida; 3- Glomus mosseae; the nutrient depletion zone Coyne, 2004 AMF Spore on and inside root
4- Glomus intraradices and 5- Glomus etunicatum
Arbuscular mycorrhizae
AMF species Rank Abundance Proportion Accumulative
(Descriptive names) frequency
fungi colonization in
A. scrobiculata 1 622 32.3 32.3
roots characterized by
Acaulospora fulvous 2 261 13.6 45.8
intercellular vesicles in
All fertilizer minus K
cortical cells and
Glomus rusty (m) 3 223 11.6 57.4
intracellular arbuscular
Glomus ivory 4 184 9.6 67
structures, the site of
Glomus straw 5 164 8.5 75
nutrient exchange
Acaulospora hyaline 6 128 6.6 82.1
between the planr and
Glomus rusty (s) 7 111 5.8 87.9
fungi
Glomus aggregatum 8 98 5.1 93
Vesicles between cortical cells
Acaulospora rusty 9 33 1.7 94
Gigaspora 10 19 1.0 95.7
Glomus sporocarpic 11 15 0.8 96.5
Commericial AMF inoculum
Acaulospora (fulv) 12 15 0.8 97.2 from Hub enterprise UK. 1B
Scutellospora ochr 13 12 0.6 97.9 Pellets of clay mineral as
Glomus fulvous 14 10 0.5 98.4 carrier of AMF inoculum.
Belos is AMF inoculum
Glomus yellow 15 10 0.5 98.9
bulking up with sorghum
Glomus cream 16 5 0.3 99.2 as the host plant.
Acaulospora orange 17 5 0.3 99.4
brown
Scutellospora hyaline 18 3 0.2 99.6
Glomus orange 19 3 0.2 99.7
Archaeospora 20 2 0.1 99.8
Banana No. of Mean spore Most abundant No. of
cultivars bananas abundance AMF species AMF Some AMF species from the rhizosphere of bananas in
sampled species
Maragua.
Cavendish 84 5.167±0.93 A. scrobiculata 16 2A 2B
Chinese 2 0 0 0
Grand naine 4 3±1.915 A .scrobicuata 2
Valery 94 6.904±2.08 A .scrobiculata 17
Williams 14 9.29±4.57 Glomus straw 11
Gros mitchel 85 6.941±2.732 Glomus rusty (m) 15
Lactan 3 1.667±1.667 A. scrobiculata 2
Sweet banana 2 20.50±17.50 Acaulospora fulv 5
Gichagara 1 0 0 0
Githumo 14 2.143±1.06 Glomus ivory 6
Kibutu 3 1.33±1.33 A .scrobiculata 4
Kiganda 2 6.5±1.5 Acaulospora hyalin
Mugithi 0 0 0 0
Muraru 36 0.472±0.216 A. scrobiculata 5
Muhato 0 0 0 0
Nyauve 0 0 0 0
Nyoro 0 0 0 0
Uganda red 2 0.50±0.5 Acaulospora fulv 1
Wood rotting fungi
Conclusion: Bananas associate with a high species number of AMF with cultivars showing preference for specific AMF species. Since AMF species vary in there effectiveness in mycorrhizal
functions, there is need to screen further species for adaptations in different cropping systems to facilitate utilization through inoculation and manipulation in the field.
Organizations: The authors acknowledge Rockefeller Foundation, Joseph Mungatu of TSBF-CIAT , Victor Otieno and Susan Njunguini of Mational Museums of Kenya