P. Ranalli et al., GENOTYPIC INFLUENCE ON IN-VITRO INDUCTION, DORMANCY LENGTH, ADVANCINGAGE AND AGRONOMICAL PERFORMANCE OF POTATO MICROTUBERS (SOLANUM-TUBEROSUM L), Annals of Applied Biology, 125(1), 1994, pp. 161-172
Microtubers of 13 cultivars, largely grown in Italy and other European
countries, were induced. They were stored in the dark at 3 degrees C
for different periods (28, 56, 84 and 105 days), prior to being transf
erred to 20 degrees C for between 4 and 17 weeks. Following removal to
room temperature, sprouting was recorded and dormancy duration quanti
fied. Dormancy decreased from 28.1 to 19.9, 11.1 and 7.8 days with red
uced time of storage. Cvs Arsy, Nicola and Jaerla took consistently mo
re time for dormancy release. The dormancy duration was linearly and i
nversely correlated with the length of storage. After sprouting, tuber
s were held at 20 degrees C for various intervals and a range of physi
ological ages (0, 368, 720 and 1008 degree days) were accumulated. The
field comparison of microtubers evidenced a plant growth response and
tuber yield/plant affected by the cultivar and physiological age. In
early cultivars (Jaerla), a better performance was shown by younger tu
bers; the opposite trend was noted in Alpha (a later cultivar) with an
increase in stems/plant, tubers/plant and tuber yield/plant for tuber
s with greater physiological age. Like conventional seed tubers, micro
tubers showed differences in optimum physiological age associated with
cultivar earliness. This study has provided some indications on how t
o enhance emergence and haulm development of plants from microtubers.