Plant Regeneration from Anther Culture of Niger (Guizotia Abyssinica (L.F) Cass.)
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Date
2008-07
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Addis Ababa University
Abstract
Niger (Guizotia abyssinica (L.f) Cass) is an important oilseed crop in Ethiopia. The outcrossing
and self-incompatibility nature of the crop make breeding works difficult. The
application of anther culture in niger improvement is very important in developing
haploids or double haploids. Double haploids enable to increase the selection efficiency
of desirable traits in recurrent selection scheme or used in producing synthetic cultivars.
Identification of the best responsive genotypes and appropriate media for callus induction
are prerequisite to regenerate plants using anther culture technique that supports the
breeding program. Anthers of four niger varieties namely Shambu, Kuyu, Esete and
Fogera were cultured into four different basal media (MS, B5, N6 and LS). All basal
media were supplemented with 2 mg/l 2, 4-D + 0.3mg/l KN or 2 mg/l NAA + 0.3 mg/l
KN. Identification of the appropriate stage of harvesting capitula and optimization of the
time duration of cold-pretreatment was undertaken using anthers of Shambu. Callus
induction experiment was also conducted on MS, B5 and NN media to identify the types
of calli induced. Various experiments were carried out to optimize callus induction, shoot
regeneration and rooting of plantlets using different combinations and concentrations of
PGRs. Data such as callus induction percentage, types of induced calli and regeneration
percentage of shoots and roots were collected and analyzed. Capitula (buds) fully or
slightly covered by sepal having whitish- green or greenish-yellow anthers were the
optimum stages of harvesting capitula and 24 hours time duration was recommended for
cold pretreatment at 40C. ANOVA showed that genotypes and media significantly affect
callus induction percentage and regeneration. The effect of the two factors, however, is
independent. The average callus induction percentage was highest in Shambu (29.4%)
followed by Fogera (21.4%) in the same treatment. It was possible to distinguish
embryogenic calli (EC) from non-embryogenic calli (NEC) by visual observation. NEC
were identified by their friable morphology and amorphous texture, which were
dominantly developed in MS media. Embryogenic calli were mainly produced in NN and
B5 media, which were distinguished by their variable texture and colour between the two
media. Among ten and nine different PGRs combinations and concentrations, 2 mg/l 2,4-
D + 0.3 mg/l KN and 2 mg/l KN + 1mg/l IAA were found to be superior PGRs
combinations for callus induction and for shoot regeneration respectively. It was also
found that 0.5mg/l IBA was the better PGR for rooting. Regenerants of Shambu seem to
be having better survival rate than the variety Fogera either in the growth room or glass
house.
Key Words / phrases: Guizotia abyssinica (L.f) Cass., anther culture, embryogenic callus, nonembryogenic
callus, basal media, plant growth regulators.
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Keywords
Guizotia abyssinica (L.f) Cass, anther culture, embryogenic callus, nonembryogenic callus, basal media, plant growth regulators