Y. Goto et al., EFFECTS OF SHORT-PERIOD TREATMENTS AT LOW -TEMPERATURE (9-DEGREES-C) ON GROWTH OF RICE PLANTS AT THE TILLERING STAGE, Nippon Sakumotsu Gakkai Kiji, 63(1), 1994, pp. 48-54
The rice plants cv. Sasanishiki (3 plants/pot) were moved into the con
trolled growth chamber at C when half of the leaf blade (LB) of the 7t
h leaf (L7) was emerged (H plot) or when the whole 7th leaf blade (LB7
) was fully emerged (W plot). The plants were kept at that temperature
for 1, 2, 4, and 8 days. Plant did not grow during the treatment and
began to continue the growth after treatment. In the 8-day treatment p
lots (H8 and W8 plots) plants sustained heavy damage and at 1 or 2 wee
ks after the treatment about 30% of plants had died.The effects of the
treatments on the leaf length or on the tillering behaviour are as fo
llows. 1) the length of LB and the leaf sheath (LS) treated at rapid e
longating stage (LB7, LS7, LB8 of H plots and LS7, LB8 of W plots) wer
e shorter than that of untreated plants, but on the other hand the len
gth of LB or LS treated just before the rapid elongating stage (LS8, L
B9 of H plots and LS8, LB9, LS9, LB10 of W plots) were longer than tha
t of untreated plants. Tiller growth of the treated plants was slower
than that of untreated plants. The percentage of emerged tillers at ex
pected nodes after treatment was smaller than that of untreated plants
. The percentage of emerged tillers and the tiller growth rate indicat
ed the rate of the damage that plants sustained. In this study, there
were no reason to say that a tiller bud was sensitive to low temperatu
re in the specific developmental stage.