トマト果実肥大期における光合成産物の転流分配に及ぼす生長調整物質 (4-CPA) の影響

Abstract

Studies were carried out to elucidate the effects of 4-CPA (4-chlorophenoxy acetic acid) on translocation and distribution of 14C-assimilates in fruits growth of tomato.The distribution pattern of 14C-assimilates from the leaves just above and just below the 1st inflorescence was changed by 4-CPA (15ppm) treatment. The accumulation of 14C-assimilates to the 1st inflorescence started earlier and increased rapidly. However, the magnitude of the effects to the distribution pattern was different according to the leaf position. The pattern from the leaf just below the 1st inflorescence was extremely affected by 4-CPA but not from the leaf just above the 1st inflorescence, because the role of leaf to 1st inflorescence is different. That is, the sympodial branching system and the degree of connection of vascular bundles affect the distribution pattern. These phenomena were also found in the various leaf positions in other experiments.From these results, it can be shown that 4-CPA is the activator of the sink or activates the sink earlier. However, it is probable that the increase in accumulation of assimilates to the inflorescence is not a direct effect of 4-CPA, because the effects sometimes do not appear by the fail of timming of 4-CPA treatment.It seems that the latant ability of the flower itself for development is fully brought out by the activation of the sink or the acceleration of accumulation of assimilates with 4-CPA treatment.