Poster for CIAT 2009 Knowledge Sharing Week

1. Centro Internac ional de Agric ultura T
International Center for T
ropic al
ropic al Agric ulture
Identification of waterlogging tolerant Brachiaria hybrids
Joisse Rincón, John Miles and Idupulapati Rao
International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia (E-mail: j.rincon@cgiar.org)
Introduction Results
10
Mean = 7.68
CIAT 6133 LSD 0.05 = 2.09
CIAT 26110
BR05 1609 8
Green leaf biomass (g pot-1)
CIAT 6133
CIAT 679
CIAT 606
6
BR04 2069 BR06 0850
BR05 1469 BR02 1794
4 BR05 1609
BR06 1000
Mean = 1.96 CIAT 6294
2
LSD 0.05 = 1.51
CIAT 36061
Check cultivar Tolerant hybrid Sensitive hybrid
CIAT 36087
0 MX02 03641 BR05 0334
BR05 1469
Figure 2 . Influence of waterlogging on shoot growth at
Material and Methods harvest time (15 days of waterlogging treatment). One 0 2 4 6 8 10 12 14
check cultivar, tolerant hybrid and sensitive hybrid.
Dead leaf biomass (g pot-1)
Two trials were conducted outside in Forages patio
area of CIAT Palmira during 2008 to determine 100
Figure 4. Relationship between green leaf biomass and
Mean = 34.5 CIAT 6133
differences in tolerance to waterlogging among 79 LSD0.05 = 5.46 CIAT 679 dead leaf biomass for 79 Brachiaria genotypes under
Brachiaria genotypes (5 hybrids of BR02NO series; 8 waterlogging treatment for 15 days. Brachiaria
Green leaf biomass proportion (%)
80
hybrids of BR04NO series; 20 hybrids of BR05NO genotypes that developed greater green leaf biomass
series; 10 hybrids of MX02NO series; 28 hybrids of CIAT 26110 and lower dead leaf biomass were identified in the
BR06NO ; 3 parents - CIAT 606; B. Ruz 44-02; CIAT 60
CIAT 606
upper, left hand quadrant.
6294; and 5 checks - CIAT 679; CIAT 6133; CIAT BR04 2069
26110; CIAT 36061; CIAT 36087). Waterlogging 40
BR06 0850
BR05 01609
treatment was imposed by applying excessive Mean = 20.61
CIAT 6294
BR02 1794 BR06 1132 Table 1. Correlation coefficients (r) between green leaf
water to the pots (5 cm over soil surface) for 15 LSD0.05 = 13.78 BR04 3207 biomass proportion (%) and other shoot traits of 79
days. The two trials were planted as randomized 20 Bruz 4402 Brachiaria genotypes under waterlogging in an Oxisol
complete block with seven replications. Each CIAT 36061 from Santander de Quilichao.
CIAT 36087
experimental unit consisted of one pot filled with 0 BR05 0334
MX02 03641
3.5 kg of fertilized top soil (0-20 cm) from Santander BR05 01469
de Quilichao’s Oxisol and sown with two Plant traits Waterlogging
20 25 30 35 40 45 50
vegetative propagules (stem cuttings). An Green leaf biomass (g pot-1) 0.91***
adequate amounts of fertilizer were supplied to the Total chlorophyll content (SPAD)
Total chlorophyll content (SPAD) 0.48***
soil at the time of planting. Plants grew for 60 days Green leaf area (cm2 pot-1) 0.81***
under 100% field capacity of soil moisture. Leaf Figure 3. Relationship between green leaf biomass
proportion and the total chlorophyll content for 79 Dead leaf biomass (g pot-1) -0.66***
chlorophyll content (in SPAD units) and leaf
Brachiaria genotypes under waterlogging. Brachiaria Stem biomass (g pot-1) 0.36***
photosynthetic efficiency (Fv/Fm) were measured
genotypes that developed greater green leaf biomass Leaf photosynthetic efficiency (Fv/Fm) 0.44***
at weekly intervals during the treatment. At the proportion and total chlorophyll content were identified
end of the 15 days of treatment, green leaf area in the upper, right hand quadrant.
(cm2 pot-1), green leaf biomass (g pot-1), dead leaf *, **, *** Significant at the 0.05, 0.01 and 0.001 probability
levels, respectively.
biomass (g pot-1) and stem biomass (g pot-1) were
measured and green leaf biomass proportion to At 7 days after of establishment of waterlogging
total shoot biomass was determined. stress, the majority of plants turned chlorotic. At 15
days after waterlogging treatment, several hybrids
Waterlogging Phenotypic Harvest were dead. Two checks, B. humidicola CIAT 6133 and
treatment differences
CIAT 679 were outstanding in total chlorophyll
content, green leaf biomass proportion to total shoot Conclusions
biomass and had lower dead leaf biomass (Figures 3
c.
and 4). Three hybrids BR04NO/2069, BR06NO/0850
and BR05NO/1609 were superior in their production of Identified three hybrids (BR04NO/2069,
a. b.
d. green leaf biomass (Figure 4). Two other hybrids BR06NO/0850 and BR05NO/1609) that were superior
Physiological variables Waterlogging for two c. Stem, green BR04NO/3207 and BR06NO/1000 showed moderate to the other hybrids in their tolerance to
a. Chlorophyll content leaf, dead leaf
b. Photosynthetic efficiency
weeks
biomass. level of tolerance to waterlogging based on green waterlogging.
d. Leaf area. leaf biomass proportion to total shoot biomass (Figure
3). Among checks the hybrid cv. Mulato 2 (CIAT This study clearly showed that there is marked
Figure 1. Methodology for screening Brachiaria
36087) showed lower level of waterlogging tolerance. genotypic variation in waterlogging tolerance in
genotypes under waterlogging conditions.
Brachiaria and we could quantify the differences in
waterlogging tolerance based on four plant traits
including green leaf biomass, green leaf area, leaf
References chlorophyll content, dead leaf biomass and green
leaf biomass proportion to total shoot biomass.
Baruch Z. 1994. Responses to drought and flooding in tropical forage grasses. Plant and Soil 164: 87-96.
Días-Filho M. B. 2001. Tolerance to flooding in five Brachiaria brizantha accessions. Pesq. Agropec. Bras., Brasilia, 37:
439-447. Acknowledgements
J. Rincón, R. Garcia, J.W. Miles and I. M. Rao (CIAT). 2007. Genotypic variation in waterlogging tolerance of preselected
sexual hybrids of Brachiaria. In: Tropical Grasses and Legumes: Optimizing genetic diversity for multipurpose use (Project
IP5). Annual report 2007. CIAT. Cali, Colombia, pp 46-47.
This work is partially supported from the funds of
I. M. Rao, J. Rincón, R. Garcia, J. Ricaurte and J.W. Miles (CIAT). 2007. Screening for tolerance to waterlogging in
Brachiaria hybrids. Poster paper presented at the international annual meeting. ASA-CSSA-SSSA. 2007. Grupo Papalotla, Mexico.