Genotypic responses of Brachiaria Grass (Brachiaria spp.) accessions to drought stress
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Date
2018Author
Cheruiyot, Duncan
Van den Berg, Johnnie
Midega, Charles Aura Odhiambo
Pickett, John Anthony
Khan, Zeyaur Rahman
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Background and
O
bjective:
Brachiaria, a warm season C4 grass, is rapidly gaining popularity as fodder crop in Africa where it is also used
as
a
component of a habitat management strategy for maize stem
borers. However, increasing drought limits productivity of this
grass
species. The aim of this study was to evaluate and select high yielding brachiaria genotypes under simulated drought condition
s.
Materials and Methods:
The morphological and physiological performance of 18 apomictic accessions of brachiaria in simulated drought
conditions in a screen house were evaluated. Plants were expose
d to different watering regimes. Well-watered (control) plants
were
watered every 48 h to 100% field capacity while drought was sim
ulated by suspending watering for 14 and 28 days, representing
moderate and severe drought conditions, respectively. Shoot len
gth, leaf length and width, number of tillers, leaf relative wa
ter content,
chlorophyll content and above ground biomass were studied.
Result:
Water stress had negative effects on the morphological and
physiological traits, with the effects being more pronounced un
der severe drought stress. Based on the drought stress index (D
SI) values
for the measured parameters and Principal Component of Analysis
(PCA) biplots, the following accessions were least affected under severe
drought stress: ‘Xaraes’, ‘Piata’, ‘Marandu’, ‘CIAT 679’, ‘Mulato II’ and ‘Mulato I’.
Conclusion:
Under increasing drought conditions, biomass
yield was an accurate predictor of drought tolerance of the gen
otypes. ‘Piata’ and ‘Xaraes’ combined both drought tolerance an
d biomass
yield. These two accessions were proposed as of value in improv
ement of the sustainability of cereal-livestock farming systems
under
conditions of increasing aridification.
URI
http://hdl.handle.net/10394/28625http://docsdrive.com/pdfs/ansinet/ja/2018/136-146.pdf
https://doi.org/10.3923/ja.2018.136.146