Effect of photoperiod on microtuber production
MS medium supplemented with 4 mg/L KIN
showed best response in tuberization. Hence, only
this treatment was used to study the effect of
photoperiod on microtuber production. The results
were presented in Table 2. In vitrotuberization
potentiality of Diamant variety was influenced by
photoperiod. Tuber formation period of the culture
was the lowest (21.93 days) under dark condition
and it was the highest (35.07 days) in light
condition. Number of tuber per explant (1.93) and
average weight (305 mg) of microtuber were also
higher in dark condition than light condition. Under
light condition most of the culture produced green
microtuber. It might be due to synthesis of the
alkaloid solanin. It was also interesting to note that,
green micro tuber produced sprouts (Fig 2 &3).
Similar phenomenon was reported by Wany and
Hu (1982). On the other hand, brown coloured tuber was observed in dark condition and did not
showed no sprout initiation. The experimental
finding reveal that, dark condition is favorable for
tuberization. Mares et al. (1981) observed that
microtuberization at 16 or 24 hours photperiod was
better than 8 hours. Wattimena (1983) indicated
that the longer the photoperiod, better was the
tuberization.