International Journal of Horticulture, 2017, Vol.7, No.17, 138-145
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was changed, from off white creamy to brownish then data were noted. In addition to this, another morphological
parameter viz., Stolon length, flesh color, skin color, were also measured. In stolon length, solons from all media
were taken and their height was measured and the height was ranging from 4 cm to 7 cm. While skin and flesh
colors were off-white creamy in case of microtubers from all media to be studied.
Table 4 Response of photomixotrophic conditions of all tuberization media on
invitro
tuberization
TM 1 TM 2 TM 3 TM 4 TM 5 TM 6 TM 7 TM 8 TM 9
Number of days to stolon induction
6 days 6 days 9 days 4 days 3 days 11 days 13 days 9 days 19 days
Average stolon length
6.2 cm 5.8 cm 4.3 cm 6.2 cm 7.9 cm 5.0 cm 3.7 cm 2.6 cm 1.3 cm
Number of days to microtuber induction
------ 5 days ------ 7 days 5 days 14 days ------
------
------
Number of days to microtuber maturation
------ 33days ------ 40
days
43
days
50 days ------
------
------
Effect of photomixotrophic conditions on histoanatomy
: Effects of photomixotrophic conditions on histoanatomy
of microtubers were also investigated. The anatomical structure of a typical potato is seen in microtubers as well
as in field grown potatoes. The layer of epidermis encloses large mass of storage parenchyma, the cortical
parenchyma, which is composed of large thin-walled cells, more or less regularly arranged. This whole region is
covered with numerous starch granules in both cases. There is no clear difference in the anatomy of microtubers
and field grown potatoes. But in microtubers, there has a small constricted area in central portion indicating the
actively growing cells. The anatomical comparison showed that microtubers are closely related to the field grown
potatoes. Both have same arrangement of cortical parenchymatous cells and the same storage cells for the
deposition of starch granules. The only difference seen in microtubers is the presence of the actively growing
cells in the central region (Figure 6; Figure 7).
Figure 6 Photomicrograph of
in vitro
grown microtuber
Figure 7 Photomicrograph of field grown potato tuber
Effect of physiological age of microtubers on sucrose and starch contents
: For determining the effect of
physiological age on sucrose and starch contents spectrophotometry was done. In this experiment, sucrose-starch
transition in different physiological ages of microtubers was estimated. For this purposes microtubers of 35 days
as well as 60 days were selected. This experiment revealed that more amount of sucrose and less amount of starch
were present in 35 days old microtubers whereas the case was otherwise in 60 days old microtubers. Thirty five
