STUDIES ON MUTAGENIC EFFECT OF GAMMA IRRADIATION ON TUBEROSE (POLIANTHES TUBEROSA LINN.) CULTIVARS PRAJWAL AND PHULE RAJANI
Loading...
Date
2010
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
IARI, DIVISION OF FLORICULTURE AND LANDSCAPING
Abstract
Genetic variability is the prerequisite for any crop to be improved.
Mutation breeding is a best method identified to enhance the genetic variability in
crop within short period. During mutation breeding it is very important to find out
the radiosensitivity of the particular cultivar along with the biological material
used to irradiate, in order to find out the optimal radiation dose for the induction
of high mutation frequency. Keeping in mind the limited variability present in
tuberose the present investigation was undertaken for the improvement in this
plant by utilizing two commercial cultivars viz., Prajwal and Phule Rajani. Three
different bulb stages viz., freshly harvested bulb (B0), three weeks after uprooting
(B1) and six weeks after uprooting (B2) of both the cultivars were irradiated by
0.00Gy (control), 2.5Gy, 5.0Gy, 7.5Gy, 10.0Gy and 15.0 Gy of Cobalt-60 gamma
rays. LD50 was between 10.0 to 11.75 Gy for freshly harvested bulbs and six
weeks of uprooted bulbs of cultivar Prajwal and for all three bulb stages of
cultivar Phule Rajani. The bulbs of three weeks after uprooting found very much
sensitive to gamma irradiation, this was supported by histological study, which
showed the adverse irradiation effect on cells and nucleus of the irradiated tissues.
In some case lower dose was found to be simulative, while higher dose had
inhibitory effect on morphological parameters. Various macro mutations were
scored for increased and reduced spikes number per plot, reduced leaf number and
bulbs per clump in vM1 population. The variants observed in the vM1 generation
were reverted back in the next generation. But we isolated some of the useful
putatively stable mutants from primarily irradiated population after second cycle
of bulb propagation viz., round and elongated petal shape mutant, higher rachis
length mutant, longer spike length mutant and variegated leaf mutant. Out of three
bulb stages tested freshly harvested bulbs (B0) and gamma irradiation doses 7.5
Gy and 10.0 Gy were found suitable for mutation induction in tuberose cultivars
Prajwal and Phule Rajani.
Description
T-8351
Keywords
developmental stages, planting, tuberose, mutation, mutants, harvesting, biological phenomena, breeds (animals), genetics, biological development