Hardening of the rooted plantlet
Hardening of the rooted plantlet was done in plastic bags
containing autoclaved mixture of soil, sand and vermicompost
(3:1:1 v/v). Plants were watered, then covered
with transparent polythene bags, and kept under partial
sunlight inside a greenhouse at ambient temperature
(*26–28 C). After 15 days, the polythene bags were
removed and the survived plants were maintained inside
the greenhouse for another 15 days. These hardened
plantlets were transferred into the field. Performance of
these plants was evaluated by measuring the nutrient
composition (lutein, b-carotene, a-tocopherol and total
carotenoids) and chlorophyll content compared with control
plants. For field performance, 1-year old in vitro plant
that repeatedly subcultured and in vitro rooted followed by
hardening in green house was used upon its field transfer.
Control plants were propagated from seeds and grown in
field. These 1-year-old control plants were selected for
comparison with tissue culture-derived plants, to evaluate
the superiority of tissue culture-derived plants over control
plants for nutrient composition.