Micropropagation of Artocarpus heterophyllus LAM. and assessment of genetic stability using ISSR markers
Jackfruit (Artocarpus heterophyllus) is a multi-purpose species that provides the source of food, timber, fuel, fodder, medicinal and industrial products. The plant, however, is mostly known for its edible fibrous medium-sized fruit which is crunchy, juicy and sweet. Jackfruit can be propagate...
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| Format: | Thesis |
| Language: | English |
| Published: |
2015
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/71151/1/FP%202015%20101%20-%20IR.pdf |
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| Summary: | Jackfruit (Artocarpus heterophyllus) is a multi-purpose species that provides
the source of food, timber, fuel, fodder, medicinal and industrial products. The
plant, however, is mostly known for its edible fibrous medium-sized fruit which
is crunchy, juicy and sweet. Jackfruit can be propagated through seeds and
vegetative means. However, the seeds are known for its recalcitrant nature,
thus it cannot be stored outside for a long period of time. Thus, this study was
carried out in order to produce uniform planting materials in large quantity using
in vitro technique. Micropropagation has been proven to successfully mass
produce plantlets in a short time as well as producing disease-free plantlets. In
the experiment on optimization of seed sterilization procedure, the whole seeds
were sterilized with 70% ethanol for 1 min followed by different concentrations
(30, 40 and 50%) of Clorox® (5.25% sodium hypochlorate) for 20 min and
rinsed once with sterile distilled water. This was followed by immersion in 10,
20 and 30% Clorox® for 15 min then rinsed five times with sterile distilled
water. Tween 20 was added into the Clorox® solution as surfactant. The seeds
were successfully sterilized using 40% Clorox for 20 min + 20% Clorox for 15
min and 50% Clorox for 20 min followed by 20% Clorox for 15 min. For the
effect of different concentrations of hormones on shoot regeneration from
seeds, aseptic seeds were cultured on half-strength MS medium supplemented
with different concentrations (0, 1.0, 2.5, 5.0, 7.5 and 10.0 mg/L) of BAP and
KIN separately. BAP at 2.5 mg/L was chosen as the most suitable
concentration producing a mean number of 7.33 shoots. Shoot induction using
shoot tip and different node positions (node 1 and node 2) of seed derived
shoots showed that there were no significant differences on mean number of
shoots produced per explant between the node positions. Nevertheless, node 2
gave the highest mean number of shoots (4.47). For the effect of decapitation
on shoot regeneration of in vitro shoots there was significant difference
between the decapitated and non-decapitated shoots on mean number of
shoots produced per explant. The mean number of shoots for the decapitated
shoots reached 12.73. In the shoot multiplication experiment, node 1 and node 2 were cultured on half-strength MS medium supplemented with 3 different
cytokinin types at 5 different concentrations each; BAP (1.0, 2.5, 5.0, 7.5 and
10.0 mg/L), KIN (1.0, 2.5, 5.0, 7.5 and 10.0 mg/L) and TDZ (0.05, 0.1, 0.5, 1.0
and 2.0 mg/L). BAP at 1.0 mg/L gave the highest mean number of shoots
(17.13). BAP at 5.0 mg/L, on the other hand, gave the highest mean shoot
length (2.95 cm). BAP at 1.0 mg/L however was chosen as the most suitable
treatment in producing multiple shoots. For rooting of shoots, shoots which
were 5 – 6 cm in length were separated individually and placed on half-strength
MS medium containing different concentrations (0, 1.0, 2.5 and 5.0 mg/L) of
IBA and NAA separately. Medium containing 2.5 mg/L IBA gave the highest
mean number of roots (18.73). The control however had the highest mean root
length (3.37 cm). Nevertheless, 2.5 mg/L IBA was chosen as the best
treatment for rooting. The completely rooted plantlets were tested on 4 different
potting mixtures which were organic soil and topsoil (1:1), perlite and sand
(1:1), peat moss and sand (1:1) and organic matter, topsoil and sand (1:1:1).
The acclimatized plantlets were observed to perform best in potting medium
containing organic soil and topsoil (1:1). The percentage of plantlet survival
was 88.89%. ISSR markers were used to assess the genetic stability of the
regenerants at the fifth subculture and it was observed that some of the
regenerants evaluated showed variability compared to the mother plant. Out of
19 regenerants assesed, 15 had Jacaard’s similarity coefficient of 1.0000,
signifying that nearly 80% of the regenerants were identical to the mother plant.
From this study, it can be concluded that in vitro technique can be used as a
suitable means of propagating clonal A. heterophyllus in large quantity.
Moreover, the propagules produced exhibited high genetic stability even at the
fifth subculture. |
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