PhD

Investigations on 'Improvement of Anthurium andreanum by in vivo and in
vitro me thods ' were carried out at the Department of Pomology and Floriculture,
College of Horticulture, Vellanikkara during the period from 1998 to 2001. The main
objectives were to evolve new varieties of A. andreanum and to standardise the age of
seed and media for in vitro seed culture.
Six commercially important varieties of A. andreanum, VIZ., 'Nitta',
'Candy Queen', 'Lima', 'Red Dragon', 'Eureka Red', 'Agnihothri' and three species
of Anthurium viz., A. crystallinum, A. ornatum and A. amnicola were selected for the
study.
Characterisation of the varieties was done morphologically which showed
significa.n variations with respect to vegetative and floral characters. Year round
flowering was obtained in all the varieties. The varieties 'Eureka Red' and 'Red
Dragon' produced more number of spikes per year (8.9 and 8.0, respectively). Among
the varieties, 'Candy Queen' produced the largest spathe (17.67 cm x 13.33 cm).
Shortest spadix was observed in Red Dragon. Peduncle was straight in all the varieties
except in 'Candy Queen'.
The true flower of Anthurium is protogynous. The duration from spike
appearance to unfurling ranged from 19.00 ,days in 'Lima' and 'Candy Queen' to
25.33 days in 'Agnihothri '. Female receptivity ranged from 12 days in 'Red Dragon'
to 20.33 days in 'Eureka Red'. An interphase of 3 to 20 days was found in between
female phase and male phase. Duration of male phase ranged from 9.33 days in
'Lima' to 20.67 days in 'Red Dragon'. Early ripening of seeds was obtained in 'Red
Dragon' (145 days) while it took 208 days in 'Agnihothri'.
Pollen grains of all the varieties were more or less round in shape.
'Agnihot hri' produced largest pollen grains (25.4 u). Pollen fertility was highest in
A. crystallinum (69.8%). Pollen production was profuse during the period from June to
October.

The varieties 'Eureka Red', 'Red Dragon' and 'Lima' were supenor
regarding post harvest qualities. In vase, spikes retained colour for longer period in
varieties 'Eureka Red' (17.67 days) and 'Red Dragon' (15.67 days) and no colour
change observed in variety' Lima'. Longer periods for necrosis of spathe and necrosis
of spadix were also exhibited by the varieties 'Eureka Red', 'Red Dragon' and 'Lima'.
The same trend was exhibited in packing also.
Heritability was of moderate to high magnitude for most of the chatacters.
Values for PCV were slightly higher than those of GCV. Plant height recorded highest
PCV (70.57).and GCV (69.96).
Out of the 42 combinations of hybridization tried, 17 were found
compatible. All the self crosses and interspecific crosses were found incompatible.
Among all the combinations,. 'Lima' produced the largest number of compatible
crosses as well as high seed set and germination percentage (compatibility score 28).
The varieties 'Candy Queen', 'Red Dragon' and 'Eureka Red' also performed well as
good female parents. Comparing the performance of male parents, the most successful
variety was 'Lima' with a total compatibility score of 31 from 5 successful cross
combinations, followed by the varieties 'Red Dragon' and 'Eureka Red'. Out of the 17
successful combinations, the highly compatible crosses were 'Candy Queen' x 'Lima',
'Lima' x 'Red Dragon', 'Lima' x 'Eureka Red' and 'Eureka Red' x 'Red Dragon'.
The protocol for immature hybrid seed culture (in vitro) in anthurium was
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developed. Seeds, 40-45 days before field maturity could be used for in vitro culture,
thus reducing the time lag for the production of hybrid seedlings. Germination and
further development were good in ~ MS + 1 mg r' BA. For callus initiation, ~ MS
with BA 6 mg r', NAA 3 mg r' was effective. For rooting and growth enhancement,
~ MS with BA 0.5 mg r' and IAA I mg r ' proved good.
Irradiation of seeds reduced germination percentage and further growth.
Callus irradiation at 0.5 to 10 Gy was.not effective. Lower dosages induced pale green
leaves and clustered appearance while higher doses induced browning of cultures.

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Survival of plantlets was the best in the media sand + cocopeat + husk
pieces (1: 1 : 1) and sand + trichoderma treated cowdung + husk pieces (1: 1: 1). White
plastic tea cups with holes at the bottom and sides were found good for planting out of
plantlets. When immature seeds were cultured in vitro, plantlets could be transferred
to the field by 6-7 months. These plantlets flowered by 1 ih month. So in total from
hybridization to flowering, it took only 22~24 months whereas in conventional method
it took 30-35 months.
Three hybrids produced flowers during the period of evaluation. The
hybrid 'Lima' x 'Eureka Red; flowered l I'" month of planting out and 'Lima' x 'Red
Dragon' and 'Candy Queen' x 'Lima' flowered 12 months after planting out. Colour
variations were noticed in the hybrid flowers. Variation in banding pattern was
observed in isozyme analysis with the enzymes peroxidase and superoxide dismutase,
while comparing parents and hybrids.