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REGULAR ARTICLE
In vitro screening of rice (Oryza sativa
L) callus for drought
tolerance
Shabir H. Wani, Parvez A. Sofi, Satbir S. Gosal,
Naorem B. Singh
Communications in Biometry and Crop Science (2010) 5 (2), 108-115.
ABSTRACT
While drought resistance is become of increasing importance in rice (Oryza
sativa L.), selection under actual field conditions is tedious due to
low heritability and time required. Selection in tissue culture is
thought to be one way to improve selection efficiency, but this requires
standardized protocols. Rice cultivars PAU 201 and PR 116 showed
significant callus induction, but the capacity for callus induction and
regeneration decreased under polyethylene glycol (PEG) (6000) stress in
both cultivars. Calli were induced on semisolid Murahige and Skoog (MS)
medium supplemented with 2.5 mg l-1 2, 4-dichlorophenoxy
acetic acid (2,4-D) + 0.5 mg l-1 kinetin (kin) + 560 mg l-1
proline + 30 g l-1 sucrose + 8 g l agar-1.
Embryogenic calli showed shoot regeneration on MS medium supplemented
with 2.0 mg l-1 benzyl aminopurine (BAP) + 0.5 mg l-1
kinetin + 0.5 mg l-1 napthalene acetic acid (NAA) + 30 g l-1
sucrose + 8 g l-1 agar. Increased levels of PEG (6000) (0,
0.5, 1.0, 1.5, 2.0 %) were used to create water stress. There was
reduction in callus induction ability and plant regeneration efficiency
with increasing levels of PEG (6000) stress. These results indicated
that PEG (6000) can be used as water stress creating agent under in
vitro conditions and rice variety PR 116 was relatively tolerant to
drought stress as compared to PAU 201. This study will serve as a base
line for in vitro screening of drought tolerant transgenic rice.
Key Words: Oryza sativa; PEG;
drought stress; callus induction; plant regeneration.
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