The influence of paclobutrazol on the distribution and utilization of ¹⁴C-labelled assimilate fixed at anthesis in oil-seed rape (Brassica napus L.)

Abstract

SUMMARYUntreated and paclobutrazol-treated field-grown plants of winter oil-seed rape cv. Jet Neuf were exposed to 14CO2 at anthesis. Redistribution of labelled assimilate was followed in sequential harvests between exposure and maturity.Labelled assimilates moved progressively from the leaves into the stem and reproductive parts. At maturity 9% of 14C fixed at anthesis had been mobilized into reproductive organs. Paclobutrazol increased the proportion of 14C translocated to the uppermost branches especially the terminal raceme.It is suggested that stem reserves are valuable for yields commonly achieved in U.K. commercial practice.

14CO2 Assimilation and Translocation of 14C‐Photosynthates by Different Parts of Indian Mustard (Brassica juncea L.)

“…During all three growth stages, leaves are the major sites for '''GO2 fixation and their contribution declined with plant age and the contribution of stem and pod walls to total ^"'GOz fixed by the plant increased with age. Our results are in agreement with the results of CHAPMAN et al (1984), BRAR and THIES (1977), INANGA et al (1979), ADO-QUAYE et al (1985) for oil seed rape. The reduction in '"^COi fixation by lower leaves was due to the onset of senescence in the lower leaves (GHAPMAN et al 1984).…”

“…been studied in Brasslca napus and B. campestris (BRAR and THIES 1977, GHAPMAN et al 1984, FREYMAN et al 1973, MAJOR et al 1978, ADO-QuAYEet al 1985, 1986. However, in Brassica juncea the role of different parts in '•*GO2 fixation and photosynthate translocation had not been investigated.…”

Effect of growth retardant soil residues on succeeding agricultural crops

“…Stem DM was not altered because, although stem length was reduced, stem width was increased. Addo-Quaye et al (1985) also found that in oil seed rape (Brassica napus L.) paclobutrazol did not always reduce stem DM, even though stem length was significantlyreduced. The increase in root DM recorded in rape grown in soil with paclobutrazol residues was similar to that previously reported for sugar beet (laggard et al 1982), carrot , and perennial ryegrass (Hampton & Hebblethwaite 1985a).…”

13C and 15N partitioning among shoots, roots, and soil in Brassica napus genotypes varying in seed oil content potential

“…For example, line 04C204 with the highest SOC potential had the lowest root to shoot ratio, indicating that this genetic line retains relatively more of its biomass in shoots rather than partitioning it to roots. Although line 04C204 had the lowest absolute amount of biomass accumulate among the four genotypes, the root to shoot ratios may be indicating that biomass partitioning among plant components is more important in determining SOC than the absolute amount of biomass accumulated (Addo-Quaye et al, 1985;Rood et al, 1984). This may be related to the fact that activity of key enzymes involved in triacylglycerol synthesis (e.g.…”