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Analysing Partitioning Of Recently Fixed And Of Reserve Carbon In Reproductive Phaseolus Vulgaris L. Plants, Donald Geiger, Wen-Jang Shieh

Donald R. Geiger

Partitioning of recently-fixed carbon among plant organs and subsequent distribution of reserve carbon were studied by supplying whole shoots of bean plants (Phaseolus vulgaris L.) with 14C-labelled CO2 of constant specific radioactivity throughout a photoperiod. The gain of tracer carbon in each part revealed net accumulation of recently-fixed carbon from direct fixation, import or both. Growth rate coefficients describing the present pattern of plant growth were calculated from ratios of tracer carbon to total carbon present in plant organs and were used to project future plant form. The period 10–20 d after the start of flowering was marked by a …