サトイモ培養球茎株の乾物生産特性および<SUP>13</SUP>C同化産物の転流•分配

Abstract

Taro plants grown from lg corms propagated by in vitro culture (IP plants) and those grown from standard 50g corms (ST plants) were compared with respect to dry matter production, their partitioning and the translocation of assimilates for 24hr after exposure to 13CO2.1. The relative growth rate (RGR) of IP plants was faster than that of ST plants.2. IP plants exhibited a faster net assimilation rate than did ST plants except between April 4 to May 20 when the rate was equal and from Sept. 24 to Oct. 14 when IP plants had a slower NAR than did the ST plants.3. IP plants partitioned more dry matter to corm and cormels than was retained by the foliage during the early growth stage. In ST plants, conversely, more dry matter was retained in the foliage during the first half of the growing season.4. Although almost 70% of the total 13C-labelled assimilates translocated to the corm and cormels in IP plants on July 14, only 35% of them did in ST plants.5. The amount of recoverable 13C-labelled assimilates retained by the foliage of ST plants on September 9 (44.1%) was less than that detected on July 14 (58.3%) ; thus, a significant amount always remains unexported in the foliage.6. The increase of cormel number in IP plants strengthens the sink demand compared with that of ST plants. It also seems that sink strength of cormels is relatively stronger than corm in IP plants.7. The rapid accumulation of assimilates by cormels of IP plants is attributed to their fast growth rate.