>.---.-...-. I’I~P:I,I MINAIIY ...
>.---.-...-.
I’I~P:I,I MINAIIY S’l’IIDllG O N IWJII NJ;TRWEN
P’lXlNG ‘I’RIWS IN SENEGAL
hllSTIlh(“l
I
,
IIe c’ au s <’
0 1 thc dcstruc.Lion o f forests f o r agricultural
needs, thcre i s a continuous d e g r a d a t i o n o f s o i l s .
T O refor-
est thesc s o i l s ,
it i s necessary t o u s e t r e e s t h a t cari tbrive
i II w a Y t c d s 0 i 1. s ,
Yortunately such t r e e s exist snd t h e y .rre
mninly Nitrogcu Pixing Trees (NPT).
Four speciea of NFT yere
studied:
P r o s o p i o afrioana, Prosopis j uli flora, Albizia
I 0 1) ho (9 k 1)
mfl Irvrr~!eurra
lnuooo~pl~ala.
Prosopiu nfricunu
and
Albiaia ïcbbeck were well n o d u l a t e d i n S o u t h S e n e g a l s o i l s
whcrcas l’r~oposiri jul.iJ’Low~ trrld Lcltaaenq 7 . 0 woccph7.a vert2 flot
nodulütcd II~ t h i s nrea. Irl~izobl~ straius ‘were i s o l a t e d f r o m
tho NPT spacics and thelr haut s p e c t r u m d e t e r m i n e d .
Nitrogan
f i x a t i o n was cstimatcd iu the l a b o r a t o r y b y m e a s u r i n g t h r
shoot and nodules dry weight and, s h o o t t o t a l N c o n t e n t .
The
four NFT sprcirs sLudil~d fcll into two CstegorieS:
(Y) NFP
cor which nitrogou tixation could significantly b e i n c r e s s e d
by i n o c u l a t i o n with the strains w e h a d i s o l a t e d (i.e. Fropesis
africana und AZùizia Zebbeck). Rhizobium strains hl10 a n d P a ,
w e r e m o s t e f f e c t i v e s t r a i n s o n these two N F T s p e c i e s .
(b) IrtT
Tor which nitrogen f i x a t i o n could n o t signiticantly b e incre-
;I:;V~ b y inoculation wiLh o u r struins (i.e. Prapo8ix jrtlt f!ora
twtl /,e uL*ut->na ICJ wowphz7.a).
The. r e a s o n o f t h i s f a i l u r e i s
I)robably chat strains native t o Senegalesc s o i l s vere n o t
vTfccL i v c on Lh~sr LWO NY’I’ spccics.
INTRODUCTION
‘P~IC EirsL ol~jucCivo was to study tlre nodulation of four
NiLroyen P’ixing ‘i’rees (NE’%‘) , l’rooopis aIrricana, Proaopis juli f-
Lo PLI, A Lblxia Ic~bbcck antf Le~wue~~u l e ucocephala then t o
Lsol ;I\\.c liiliüul1: LUI strilins ~IX.XU those NYT a.nd finally to
c2stimate nitrogen f i x a t i o n i n thr laboratory.
MATERIALS A N D MlWIIODS
L*‘or isolotin9 /i/li301)z’ LOI strnins from thc five dj.fferent
s o i l s stud.Lcd (Tz~Lle 11, yerminated s e e d s o f the f o u r species
were p l a n t e d i n p l a s t i c pouches 24 x 1 1 c m filled with the
different s o i l s .
‘PIE sceds h a d b e e n s t e r i l i z e d hy immersion i n
conccntrotcd
sulyhuric ncld ( T a b l e Z), a treatn~ent which was
neccssüry t o allow the g e r m i n a t i o n (chemical. s c a r i f i c a t i o n ) .
NFT IN SRNIIGAI.
Table 1.
Characteristics o f five Soutli Scnegnl s<: i 13,
Clny
Finfi
Conrnc
F i 11 c
cnrlrH<’
0 r 1: :t II i C’
pll KCI
Soils
Loam
L0am
s 11 11 CI
s a II tl
m;lLlcr
x
x
2
2
2
2
Soils
c4 NA
P205 zI3similnhle
Diouloulou
7,4
0,50
0,012
Dj ibelot
7,4
0,50
0,017
Bayottes
10‘7 Os60
0,010
Dabo
8‘3 0,5O
0,012
BotOu
7,4
0,53
0,010
Table 2:
Sterilization o f the sccds and g e r m i n a t i o n test.
--~
Duration
Durnt ion
Dcirntion
Porc!cntngo of
o f ster- o f imne- o f serds
germination
,$.
ilizati-
sion i n
~crmina-
o n ( m n )
1120 (mn)
t ion (II)
<l ,l
0 Il
n gn r
s il Il tl
F. nfricatta
120
120
4 8
72
4 0 L I, 6 0
f‘. j rrt i fLorw
15
6 0
2 4
4 s
9 0 t. 0 9 5
A.
tehbeck
60
6 0
2 4
4 8
90 t o 95
L.
Ic Iwm?plln Ln
30
6 0
2 4
4 8
no to 100
The experimexit was conducted with I-.hrcc sccdlings per pouch
for thc four NYT nnd fif tcen r'vpl i C&I~ c:: ,W r L: t’<!nI.mcxlL.
,
Rhizobia were isolated from the nodules that apnearcd after
35 days.
Isolates were then plated in pctri dishcs containing
t h e r o u t i n e YEMA medium (Vincent, 19701.
Infection plant tests worc carrtcd out in Gibson tube
(Gibson 1963) containing agar Jenscn medium (Jensen, 1942).
j
SeedLings wcre inoculated with a 7-day-old cul.t:urc of thc iso-
lated Rftizobiun strains and the ORS 911 nnd Cb 756 as rcfcrcncc
429
NW I N 61JCNBQAI.
/t/l i::011 i. wfl strains.
Nitrogen fixation was estimated by diffe-
I‘VIJC~. IIC~LW<~C*II Lho Lot a1 N content of non,-inoculated and inocu-
1 ntt>d p1nnts.
111 ndcli t- ion, oven dry weights of nodules .and
SllOOLS
wow dutcrminod.
RKSUI,TS
1.
~odulnLiol\\ oc Lhc NY'P:
Prueopis aj?:ican and dZbizir7
1~bl~~!c?k nodulated in a11 soils used but the number of nodules
was highnst in Bnbo S0i.l.
P. JU~~~ZOPCJ and L, l~*J<~~~c~~~i:<~!~
did rlot nodulnte in any of thS soils (Table 3).
2 ,
Isolation of
/i/tizobiurrt strains and study of their host
range:
Tcn strains were isolated, a11 o.E them from P. api-
OUnrl illlil A. I(~I~l~cctk,
'I'lJc6c strains intli.lferently nodulated
1'. af'r*iuun« nnd A. I<~/)I:I!<*~ and most of irhem were effective
o n hoLI1 hosts.
Only tqzro of these strains (Pal from P. api-
ounu nnd Al 4 froc A. IeDbctik) were able to effectively
nodulatc t. la wflccp/~u %a.
None of the ton strains isolated
was ablc to nodulnte P. ,iuI.<fZnm.
Jnlcrcstingly ORS Y21 (isolated from Acucia j'urnesisnn)
WikS a!,lc t o nodulatc 1 , .
l~?rrcocophala (Table 4). The effect-
ivcnr~.s.s of t-llc? :3tr;llllS
was dctermined only with 1'. .zjI+iznnz
~lll<l
A. L~!III~~~~~/c anù tlle Lest strains were AllC an<- Pa , (Fig.
1, 2 ;mci 3) .
CONCLUSION
WIO J~rc?liminary investigations of the four species of NFT
:;Ilow<~tl
CII,11 LllCSC? spccics
fell into two inoculation groups
according to thc I;l~ir~~l~ iltrr that nodulated them:
the first
group Includkl J’twrtc~/~if:
uft*ioun unil AllJi.üi<t
z,:l*b,~,~k which
nodul;JLc~tl r~;nli ly wl CEJ I~'lrinol~ c WI strnlns dlstributcù in thc
five Scnegalcsc soils studied (which are probnbly ubicluitous
strains).
Son10 of tlic I;liiüob% Jm strains were fast growing
while otliers wcrc slow growing.
Thcre was no relation betrreen
t tw ~~1'1'IcIcmc:y 01' t.lk~:k~ :;Lrcilns muid tlioir growth rate.
The
second group includcd
1’tw::opi:t j ul iJ’1o~~t and. I,GI~~*Q<~~~o
Zeucooepltata'did not nodulate with the native RhiaobCm
4 3 0
Table 3:
?iodulation of four NPT in five Seneaalese aoils
SOILS
DIOCLOULOU
DJ LBELOR
BAYOTTES
DABO
BOTOU
XFT Species
**
A*
B
A
B
A
B
A
B
A
B
P .
8 (15)
3.12
10 (15)
1.10
14 (15)
2.21
15 (15)
4.00
12 (15)
3.40
ZfTiCCl?ZCl
E
I .
0
(15)
0 . 0 0
0 (15)
0.00
5 (15)
0.00
0 (15)
0.00
0 (15)
0.00
2
juz< .Jlcrrr
P
;
_
.-. .
-Dl:90;
<>./d/..
12 !15)
1.75
10 (15)
1.30
12 (15)
3.33
15 (15)
4.60
12 (15)
3.08
m
w
-*
0 (15)
0.00
0
(15)
0.00
0 (15)
0.00
0 051
0.00
0 Cl51
0.00
0
:e -,29:jg>;r;;a
5
*A- ?;ants nodyvlated;
**3- xodulos per plaz:; 0: Xunber of plants tested.
NlT
IN SENEGAL
. .
5 0 0 0
l
(a) P. africana
E
0
e
E
1 0 0 0
0
3’
3 0 0 0
(b) A
.
Isbbsck
E
0
2
E
1 0 0 0
0
Figure 1.
SlluoL: dry wcight (* - these treùtments
wcre significantly higher than $ i.e.
<Y,,lll'O 1 ) .
T
4 3 2
NFT IN SENEGAL
i
2 0
,
i
(a) f ?
ofricana
$ 10
E
2
f ’
i
I , ,
O A
AIOP% Po, Pas Al4 Pa,Af8 h5 Al,CN$ C
3 c
(b) A . l e b b c c k
2 0
5
5
E
10
2
0
i
Figure 2.
Nod~ln d r y wciqht
433
NFT
IN SENEGAL
150
(a) P. ofriccw
l
i
100
5
P
i?
5 0
l l
l-.LLl
C zi
:
Pa
‘1 1
6
5"2A'aP%C
ORS
100
lb) A. lebbeck
2 50
0
2
E
10
0
, Al6
Figure 3 .
'Total N content (e - as in Fig. 1)
434
i
NFT IN SENEGAL
strains from these soils which suggests that lilri:cobi ~II
f
i
rtquirw:ents o f P. j 1.L if7 01-n nnP L. 7c rcc*orv!pIIn 1.u arc ITOI-0
SFeciffc th0n tlroso o f t.ho f i r s t grout?.
Tl nrqx-ar~ nc?cc:;si1ry
t o initiate i n v e s t i g a t i o n i n t h a t fielil.
Strains
Growth
PsOROp ie
ALDizia
IJC U?L!,LII~1
l'P<Jl!,,,> i,!
rate
crft*ic*trtrcz
labbcck 7.~7 ~r~ror~cpbnf.~r j t,l% florcr
I-4
faat
17
P,
R
n . i .
Pa\\
fast
E
c
II. i.
PS
slow
;
K
n.i.
n.i.
Pa5
slow
E
E
n.i.
II. i.
Pa7
slow
E
l%
n-i.
n . i .
A19
f a s t
E
f!
C’
c
AL2
f a s t
E
E
E
n.i.
AI4
slow
E
13
n. i.
n.i.
Al6
slow
E
II
n . i .
e
Al8
fast
E
II
n. i.
II. i.
OR&‘91 1
f a s t
E
E
li
c
CRf56
6LOW
*
c
II. i,
n.i.
B - effective; p I incfEectivc; n.i. = non-infcctivc
f - Planta o f thia t r e a t m e n t wcrc r~)IrLilsli~rilI~~~l.
4 3.5
I’I~P:I,I MINAIIY S’l’IIDllG O N IWJII NJ;TRWEN
P’lXlNG ‘I’RIWS IN SENEGAL
hllSTIlh(“l
I
,
IIe c’ au s <’
0 1 thc dcstruc.Lion o f forests f o r agricultural
needs, thcre i s a continuous d e g r a d a t i o n o f s o i l s .
T O refor-
est thesc s o i l s ,
it i s necessary t o u s e t r e e s t h a t cari tbrive
i II w a Y t c d s 0 i 1. s ,
Yortunately such t r e e s exist snd t h e y .rre
mninly Nitrogcu Pixing Trees (NPT).
Four speciea of NFT yere
studied:
P r o s o p i o afrioana, Prosopis j uli flora, Albizia
I 0 1) ho (9 k 1)
mfl Irvrr~!eurra
lnuooo~pl~ala.
Prosopiu nfricunu
and
Albiaia ïcbbeck were well n o d u l a t e d i n S o u t h S e n e g a l s o i l s
whcrcas l’r~oposiri jul.iJ’Low~ trrld Lcltaaenq 7 . 0 woccph7.a vert2 flot
nodulütcd II~ t h i s nrea. Irl~izobl~ straius ‘were i s o l a t e d f r o m
tho NPT spacics and thelr haut s p e c t r u m d e t e r m i n e d .
Nitrogan
f i x a t i o n was cstimatcd iu the l a b o r a t o r y b y m e a s u r i n g t h r
shoot and nodules dry weight and, s h o o t t o t a l N c o n t e n t .
The
four NFT sprcirs sLudil~d fcll into two CstegorieS:
(Y) NFP
cor which nitrogou tixation could significantly b e i n c r e s s e d
by i n o c u l a t i o n with the strains w e h a d i s o l a t e d (i.e. Fropesis
africana und AZùizia Zebbeck). Rhizobium strains hl10 a n d P a ,
w e r e m o s t e f f e c t i v e s t r a i n s o n these two N F T s p e c i e s .
(b) IrtT
Tor which nitrogen f i x a t i o n could n o t signiticantly b e incre-
;I:;V~ b y inoculation wiLh o u r struins (i.e. Prapo8ix jrtlt f!ora
twtl /,e uL*ut->na ICJ wowphz7.a).
The. r e a s o n o f t h i s f a i l u r e i s
I)robably chat strains native t o Senegalesc s o i l s vere n o t
vTfccL i v c on Lh~sr LWO NY’I’ spccics.
INTRODUCTION
‘P~IC EirsL ol~jucCivo was to study tlre nodulation of four
NiLroyen P’ixing ‘i’rees (NE’%‘) , l’rooopis aIrricana, Proaopis juli f-
Lo PLI, A Lblxia Ic~bbcck antf Le~wue~~u l e ucocephala then t o
Lsol ;I\\.c liiliüul1: LUI strilins ~IX.XU those NYT a.nd finally to
c2stimate nitrogen f i x a t i o n i n thr laboratory.
MATERIALS A N D MlWIIODS
L*‘or isolotin9 /i/li301)z’ LOI strnins from thc five dj.fferent
s o i l s stud.Lcd (Tz~Lle 11, yerminated s e e d s o f the f o u r species
were p l a n t e d i n p l a s t i c pouches 24 x 1 1 c m filled with the
different s o i l s .
‘PIE sceds h a d b e e n s t e r i l i z e d hy immersion i n
conccntrotcd
sulyhuric ncld ( T a b l e Z), a treatn~ent which was
neccssüry t o allow the g e r m i n a t i o n (chemical. s c a r i f i c a t i o n ) .
NFT IN SRNIIGAI.
Table 1.
Characteristics o f five Soutli Scnegnl s<: i 13,
Clny
Finfi
Conrnc
F i 11 c
cnrlrH<’
0 r 1: :t II i C’
pll KCI
Soils
Loam
L0am
s 11 11 CI
s a II tl
m;lLlcr
x
x
2
2
2
2
Soils
c4 NA
P205 zI3similnhle
Diouloulou
7,4
0,50
0,012
Dj ibelot
7,4
0,50
0,017
Bayottes
10‘7 Os60
0,010
Dabo
8‘3 0,5O
0,012
BotOu
7,4
0,53
0,010
Table 2:
Sterilization o f the sccds and g e r m i n a t i o n test.
--~
Duration
Durnt ion
Dcirntion
Porc!cntngo of
o f ster- o f imne- o f serds
germination
,$.
ilizati-
sion i n
~crmina-
o n ( m n )
1120 (mn)
t ion (II)
<l ,l
0 Il
n gn r
s il Il tl
F. nfricatta
120
120
4 8
72
4 0 L I, 6 0
f‘. j rrt i fLorw
15
6 0
2 4
4 s
9 0 t. 0 9 5
A.
tehbeck
60
6 0
2 4
4 8
90 t o 95
L.
Ic Iwm?plln Ln
30
6 0
2 4
4 8
no to 100
The experimexit was conducted with I-.hrcc sccdlings per pouch
for thc four NYT nnd fif tcen r'vpl i C&I~ c:: ,W r L: t’<!nI.mcxlL.
,
Rhizobia were isolated from the nodules that apnearcd after
35 days.
Isolates were then plated in pctri dishcs containing
t h e r o u t i n e YEMA medium (Vincent, 19701.
Infection plant tests worc carrtcd out in Gibson tube
(Gibson 1963) containing agar Jenscn medium (Jensen, 1942).
j
SeedLings wcre inoculated with a 7-day-old cul.t:urc of thc iso-
lated Rftizobiun strains and the ORS 911 nnd Cb 756 as rcfcrcncc
429
NW I N 61JCNBQAI.
/t/l i::011 i. wfl strains.
Nitrogen fixation was estimated by diffe-
I‘VIJC~. IIC~LW<~C*II Lho Lot a1 N content of non,-inoculated and inocu-
1 ntt>d p1nnts.
111 ndcli t- ion, oven dry weights of nodules .and
SllOOLS
wow dutcrminod.
RKSUI,TS
1.
~odulnLiol\\ oc Lhc NY'P:
Prueopis aj?:ican and dZbizir7
1~bl~~!c?k nodulated in a11 soils used but the number of nodules
was highnst in Bnbo S0i.l.
P. JU~~~ZOPCJ and L, l~*J<~~~c~~~i:<~!~
did rlot nodulnte in any of thS soils (Table 3).
2 ,
Isolation of
/i/tizobiurrt strains and study of their host
range:
Tcn strains were isolated, a11 o.E them from P. api-
OUnrl illlil A. I(~I~l~cctk,
'I'lJc6c strains intli.lferently nodulated
1'. af'r*iuun« nnd A. I<~/)I:I!<*~ and most of irhem were effective
o n hoLI1 hosts.
Only tqzro of these strains (Pal from P. api-
ounu nnd Al 4 froc A. IeDbctik) were able to effectively
nodulatc t. la wflccp/~u %a.
None of the ton strains isolated
was ablc to nodulnte P. ,iuI.<fZnm.
Jnlcrcstingly ORS Y21 (isolated from Acucia j'urnesisnn)
WikS a!,lc t o nodulatc 1 , .
l~?rrcocophala (Table 4). The effect-
ivcnr~.s.s of t-llc? :3tr;llllS
was dctermined only with 1'. .zjI+iznnz
~lll<l
A. L~!III~~~~~/c anù tlle Lest strains were AllC an<- Pa , (Fig.
1, 2 ;mci 3) .
CONCLUSION
WIO J~rc?liminary investigations of the four species of NFT
:;Ilow<~tl
CII,11 LllCSC? spccics
fell into two inoculation groups
according to thc I;l~ir~~l~ iltrr that nodulated them:
the first
group Includkl J’twrtc~/~if:
uft*ioun unil AllJi.üi<t
z,:l*b,~,~k which
nodul;JLc~tl r~;nli ly wl CEJ I~'lrinol~ c WI strnlns dlstributcù in thc
five Scnegalcsc soils studied (which are probnbly ubicluitous
strains).
Son10 of tlic I;liiüob% Jm strains were fast growing
while otliers wcrc slow growing.
Thcre was no relation betrreen
t tw ~~1'1'IcIcmc:y 01' t.lk~:k~ :;Lrcilns muid tlioir growth rate.
The
second group includcd
1’tw::opi:t j ul iJ’1o~~t and. I,GI~~*Q<~~~o
Zeucooepltata'did not nodulate with the native RhiaobCm
4 3 0
Table 3:
?iodulation of four NPT in five Seneaalese aoils
SOILS
DIOCLOULOU
DJ LBELOR
BAYOTTES
DABO
BOTOU
XFT Species
**
A*
B
A
B
A
B
A
B
A
B
P .
8 (15)
3.12
10 (15)
1.10
14 (15)
2.21
15 (15)
4.00
12 (15)
3.40
ZfTiCCl?ZCl
E
I .
0
(15)
0 . 0 0
0 (15)
0.00
5 (15)
0.00
0 (15)
0.00
0 (15)
0.00
2
juz< .Jlcrrr
P
;
_
.-. .
-Dl:90;
<>./d/..
12 !15)
1.75
10 (15)
1.30
12 (15)
3.33
15 (15)
4.60
12 (15)
3.08
m
w
-*
0 (15)
0.00
0
(15)
0.00
0 (15)
0.00
0 051
0.00
0 Cl51
0.00
0
:e -,29:jg>;r;;a
5
*A- ?;ants nodyvlated;
**3- xodulos per plaz:; 0: Xunber of plants tested.
NlT
IN SENEGAL
. .
5 0 0 0
l
(a) P. africana
E
0
e
E
1 0 0 0
0
3’
3 0 0 0
(b) A
.
Isbbsck
E
0
2
E
1 0 0 0
0
Figure 1.
SlluoL: dry wcight (* - these treùtments
wcre significantly higher than $ i.e.
<Y,,lll'O 1 ) .
T
4 3 2
NFT IN SENEGAL
i
2 0
,
i
(a) f ?
ofricana
$ 10
E
2
f ’
i
I , ,
O A
AIOP% Po, Pas Al4 Pa,Af8 h5 Al,CN$ C
3 c
(b) A . l e b b c c k
2 0
5
5
E
10
2
0
i
Figure 2.
Nod~ln d r y wciqht
433
NFT
IN SENEGAL
150
(a) P. ofriccw
l
i
100
5
P
i?
5 0
l l
l-.LLl
C zi
:
Pa
‘1 1
6
5"2A'aP%C
ORS
100
lb) A. lebbeck
2 50
0
2
E
10
0
, Al6
Figure 3 .
'Total N content (e - as in Fig. 1)
434
i
NFT IN SENEGAL
strains from these soils which suggests that lilri:cobi ~II
f
i
rtquirw:ents o f P. j 1.L if7 01-n nnP L. 7c rcc*orv!pIIn 1.u arc ITOI-0
SFeciffc th0n tlroso o f t.ho f i r s t grout?.
Tl nrqx-ar~ nc?cc:;si1ry
t o initiate i n v e s t i g a t i o n i n t h a t fielil.
Strains
Growth
PsOROp ie
ALDizia
IJC U?L!,LII~1
l'P<Jl!,,,> i,!
rate
crft*ic*trtrcz
labbcck 7.~7 ~r~ror~cpbnf.~r j t,l% florcr
I-4
faat
17
P,
R
n . i .
Pa\\
fast
E
c
II. i.
PS
slow
;
K
n.i.
n.i.
Pa5
slow
E
E
n.i.
II. i.
Pa7
slow
E
l%
n-i.
n . i .
A19
f a s t
E
f!
C’
c
AL2
f a s t
E
E
E
n.i.
AI4
slow
E
13
n. i.
n.i.
Al6
slow
E
II
n . i .
e
Al8
fast
E
II
n. i.
II. i.
OR&‘91 1
f a s t
E
E
li
c
CRf56
6LOW
*
c
II. i,
n.i.
B - effective; p I incfEectivc; n.i. = non-infcctivc
f - Planta o f thia t r e a t m e n t wcrc r~)IrLilsli~rilI~~~l.
4 3.5