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0.25 to 4.00 (TABU 6) In a sef of R1 famllles arising lrom a single explont, when the variants d
a similar phenotype were considered to have arlsen from a single mutational event. This
method of lrequency calcuiatlons was alw followed for sugarcane by Lee and Phllllps (1987)
and lor malze by Edallo et 01. (1981). However, the frequency of a somaclonal mutatlonol
event could be even higher because the variants of a similar phenotype may not have arisen
from a single mutational event as there could have occurred independently in different
regenerated planh due to Me presence of mutation sensMve regions In the chromosomes.
With Increase In culture time, Lee et al. (1988) observed an Increase In the frequency of variant
phenotypes In regenerated malze plants from 0.5 lo 1.3 variants per regenerated plant whlle
in wheal, Ryan et al. (1987) recovered potentially useful variation for quali characters like
increases In kernel weight, hardness and protein content and reduced yellow pigmentation.
In soybean, Barwale and Widholm (1990) reported segregation for sterili, wrinkld led
morphology, multiple branching, twin seeds and leaflet number in at least three generations
of selling. They also found the frequency of qualitative variation per lnfiial regenerant to range
from 0.05 to 1.00. Alw in malze. Zehr et al. (1986) reported average mutation frequency for
qualitative variation per regenerated plant to range lrom 0.18 to 0.71.
Among thesomaclonol population (R1 plants), the highest frequency of variants was otwrved
for the tralt seed cod pottern (41% of somaclones) followed by rtrophiolation (31% d
somaclones). About 2% each d somaclones were variant for the lralls Indeterminate and
semi-determinate. White seed coat colwr was observed In 16.4% of Me wmaclones while
colwr around hllum was observed In 18% of wmaclones. Thus a considerable amount and
type of variation has occurred in the tissue cullure generated putative maclones.
All the qualitative mutations Mat apparenffy occurred wen visible In the flnt sen-pollinated
generation. The falts such as nowering hablt, ptosence d strophiole and leaf shape ore