Abstract:
Cymbidium bicolor Lindl. is an orchid, found as epiphytes on Palmyrah (Borassus
flabellifer). The association of Mycorrhizae in the roots helps C. bicolor to survive during
drought. Therefore, this investigation was carried out to study its compatibility and
symbiosis with Chilli (Capsicum annum) and onion (Allium cepa) plants. The mycorrhizal
fungi associated with the C. bicolor Lindl. is Glomus spp. which improves the seed
germination and other plant quality parameters. Hence, during transplanting, plant
roots can be dipped in Glomus spp. solution to initiate symbiosis in the root system. The
C. bicolor plants were collected from Nelliyady, Chunnakam, Manippay, Chavakachcheri
and Karaveddy in Jaffna, Sri Lanka during February-March 2017. White actively growing
spongy root tips attached with C. bicolor were randomly collected. The fungi were
isolated and cultured on yeast extract peptone agar medium supplemented with two to
five drops of Choloromphenicol (5%) for five days at room temperature. Glomus spp.
was identified by morphology and growth pattern of mycelium and produced pure
culture was subjected to sub-culture. Using subculture, fungal solution was prepared.
The roots of seedlings (four weeks after germination) were dipped in to fungal solution
for three hours and planted according to Completely Randomized Design. Four
treatments such as Glomus spp. alone, Glomus spp. with Trichoderma viride, T. viride
alone and control tests were carried out and replicated five times. Plant height was
measured weekly until plants were uprooted and uprooted plant’s fresh weight, plant
dry weight, root coverage, number of leaves and root lets were measured. Results of the
study showed that Glomus spp. alone applied chilli plants and onion plants had higher
number of leaves, root length, plant height, number of root lets, plant fresh weight and,
plant dry weight than other treatments (Glomus spp. + T. viride, T. viride alone and
control). It was also observed that Glomus spp. and T. viride combinations gave lower
result than Glomus spp. and T. viride alone treatments. Thus T. viride could have
suppressed the activity of Glomus spp. From this study it can be concluded that dipping
of seedlings in Glomus spp. solution will improve the productivity of chilli and onion
plants.
