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Some Effects of Sucrose Concentration on Primordium Development in Excised Primary Roots

1982; Oxford University Press; Volume: 49; Issue: 3 Linguagem: Inglês

10.1093/oxfordjournals.aob.a086253

1095-8290

R. D. MACLEOD, Anne Thompson,

Plant nutrient uptake and metabolism

The effects of varying the amount of sucrose used to supplement the culture medium maintaining the growth of excised roots of Pisum sativum L., Vicia faba L., Zea mays L. and Phaseolus vulgaris L., on the rates of primordium initiation and subsequent emergence as lateral roots and on the duration of the interval between primordium inception and emergence as a secondary root through the tissues of the primary have been investigated. Variation in the exogenous concentration of sucrose from 0.5 to 8 per cent had little effect on the rate of primordium inception in Pisum and Vicia and the rates never reached the values obtained for the roots of the corresponding intact plants. Moreover, over the 6 day culture period lateral root emergence did not occur in any of the excised roots of these two species. In contrast, each of the aspects of primordium development examined in the excised roots of Zea and Phaseolus was markedly affected by the amount of sucrose used to supplement the culture medium. In addition, in the presence of about 6 per cent sucrose, primordium development in these cultured roots was very similar to that in roots of the corresponding intact plants. The results indicate either that some factor necessary for primordium development is present in adequate amounts in excised roots of Zea and Phaseolus, but not in those of Pisum and Vicia, or that the factors controlling such development are different in the former and latter two species.