2.3mm, 3.0mm, and 5.3mm at 30 ◦C, but 3.7mm, 5.2mm, and
6.6mm at 32 ◦C. These arrived at the lower style (Fig. 3). Consequently,
32 ◦Cwas the threshold temperature for promoting pollen
tube growth in these cross combinations. In reciprocal crosses,
although significant effects of temperature were found by ANOVA
testing (Table 1), pollen tubes of these three lines had elongated
less than 1mmin the pistil of ‘MR-1’ (Fig. 4). Effects of temperatures
were also evaluated in the self-pollination of PI 147065, PI 320052,
PI 526242, and ‘MR-1’. Pollen tube lengths were compared among
different temperature conditions 8 h after pollination. No significant
effect of temperature was found on the pollen tube length of
any self-pollinating plant (