Towards the selection of
phosphorus efficient rice varieties
Lalith Suriyagoda1,2, Vishna Weerarathne1, Dinarathne Sirisena3, Matthias Wissuwa4
1Faculty
of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka
2School of Plant Biology and Institute of Agriculture, The University of Western Australia, 35
Stirling Hwy, Crawley, Perth, WA 6009, Australia
3Rice Research and Development Institute, Bathalagoda, Ibbagamuwa, Sri Lanka
4Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi,
Tsukuba 305-8686, Japan
Distribution of soil P levels in different cropping
systems in Sri Lanka
Soil P range
(mg kg-1)
(Olsen-P)
<5
5 – 10
10 – 15
15 – 25
25 – 50
50 – 100
100<
Cropping System
Rice-Rice
(% fields)
9
35
24
29
3
Rice-Vegetable
(% fields)
Vegetable-Vegetable
(% fields)
5
20
32
14
29
15
17
68
(Wijewardena, 1990)
• At present rice crops in Sri Lanka do not show P deficiency
• Sri Lanka does not own high quality P reserves
• Department of Agriculture has reduced the P application rate to rice recently
Objectives
• Identify P deficiency sensitive growth and
development characteristics
• Screen the local and selected exotic
germplasms to find P efficient rice varieties
P sensitive growth characteristics in rice
Initial soil conditions
Measurement
pH
Available (Olsen) P (mg kg-1)
Total P (mg kg-1)
Exchangeable K (mg kg-1)
Value
7.4
13.8
338
84.7
DW (g hill-1)
60
Growth
P1
P0
40
20
0
2012 Yala
2012/13
Maha
Above ground DW
Grain yield
Total P uptake
Tissue [P]
vv
Plant height
vv
2013 Yala
2013/14
Maha
Variation in plant height
Plant height (cm)
Initial plant responses to declining soil P status were;
reduction in plant height, total above ground DW, total
P uptake, and tissue [P] but not the grain yield
P(+) P(-)
Weeks After Planting
Screening rice varieties for P efficiency …
Plant materials:
44 recommended rice varieties in Sri Lanka, and 36 IRRI set
Harvest:
at 6 weeks after planting (both roots and shoots)
Measurements:
Growth (DW), tissue P and K concentrations
Character
pH
Total N (mg g-1)
Exchangeable K (mg kg-1)
Total P (mg kg-1)
Available (Olsen) P (mg kg-1)
OM (%)
Only for local
Unfertilised
varieties
site (for 30
Fertilised
years!)
site
6.5
6
0.9
1.1
129
116
216
345
1.6
11.8
2
2.2
In unfertilised site both local and IRRI lines were grown
In fertilised site only the local varieties were grown
DW (g plant-1) under fertilised condition
(Olsen P 11.8 mg kg-1)
Growth of local rice varieties under low and
high soil fertility
At402
Bg357
Bg358
Bg366
Bg11-11
Bg400-1
Bg450
Bw367
DW (g plant-1) under unfertilised condition
(Olsen P 1.6 mg kg-1)
At303
At307
Bg300
Bg305
Bg369
Bw363
Bw451
Total K uptake (mg plant-1)
Total P uptake (mg plant-1)
Growth, P and K nutrition at unfertilised site
Local (44 varieties)
20
Bw451
15
IRRI set (36 lines)
Bg305
Bg300
At303
10
5
Bg400-1
Bg357
0
0
5
10
15
20
Bg305
Bg300
At303
120
80
120
GUAN YIN TSAN
80
DJ123
40
Bg400-1
Bg450
40
0
0
0
5
10
15
Plant DW (g)
20
0
5
10
15
Plant DW (g)
20
Grain P and K concentrations
K concentration (mg kg-1)
Local (44 varieties)
2000
1500
1000
Fertilized site
Unfertilised site
500
0
0
K concentration (mg kg-1)
IRRI set (36 lines)
1000
2000
3000
4000
3000
4000
2000
1500
1000
Unfertilised site
500
0
0
1000
2000
P concentration (mg kg-1)
Root DW (g plant-1)
Local (44 varieties)
At303
Bg300
Bg305
Bg369
• A wide variability in the growth and P nutrition was observed for
local rice varieties under low-fertile soil conditions,
Root DW (g plant-1)
• In general, local rice varieties performed better than the IRRI set,
IRRI set (36 lines)
• Certain local rice varieties showed promise to be used in future
breeding experiments
Shoot DW (g plant-1)
Acknowledgement
• International Foundation for Science, Sweden
• National Research Council, Sri Lanka
• National Science Foundation, Sri Lanka
• SPS2014 Organisers
• ,
Thank you