Organ Regeneration on Excised Roots of Chondrilla Juncea and Its Chemical Regulation

Abstract

Ab8tractThe effects of endogenous factors (plant age, section length, and section location) and environmental factors (temperature and mineral nutrition) upon organ regeneration on isolated root sections of Ohondrilla juncea L. were used to develop a standard assay system for the study of the chemical regulation of regeneration. Bud and root formation and its polarity in the presence of a variety of regulators alone and in combinations were observed quantitatively. Bud numbers were increased by auxin (low concentrations), cytokinin, and gibberellin treatments. High concentra· tions of auxin inhibited bud formation and this effect was reversed by antiauxin, cytokinin, or gibberellin. Adenine did not counteract auxin· induced bud inhibition but adenine and N·6·benzyladenine did counteract inhibition induced by the purine antagonist 2,6·diaminopurine. Numbers of regenerated roots were increased by auxin treatment and reduced by cytokinin and gibberellin treatment. On control and auxin· treated sections, bud formation was strongly polar and proximal and cytokinin and gibberellin treatments lessened the polarity. Growth retardants inhibited regeneration. Of a number of synthetic auxins tested, 2,4.dichlorophenoxy. acet.O.methylhydroxamic acid and 4·amino.3,5,6.trichloropicolinic acid were the most effective inhibitors of bud formation.Mechanisms for the regulation of regeneration are inferred from the results.

Intermediate growth forms as a model for the study of plant clonality functioning: an example with root sprouters

“…Higher nutrient levels support bud formation, break down bud dormancy and facilitate growth of root-borne shoots in perennial species (Peterson, 1975). However, an opposite effect was also found: the number of adventitious buds on roots of Chondrilla juncea was not affected by the nutrient level, but the growth of new shoots was supported by low nutrient levels (Kefford and Caso, 1972). According to a study by McIntyre and Hunter (1975) on another perennial weed of arable land, Cirsium arvense, root buds are initiated more frequently on plants growing at lower nutrient levels than at higher ones.…”

Factors affecting the establishment and maintenance of ?Titan? red raspberry root organ cultures

“…At least 12 species of herbaceous plants have been regenerated from root cultures via adventitious bud formation [12,18,27 and references cited therein]. On the other hand, plantlet regeneration from root cultures has succeeded only with 6 woody species, including Comptonia peregrina [8], Robinia pseudoacacia [21], Citrus sinensis, Citrus limon [20] and Dalbergia sissoo [16], and Actinidia chinensis [10].…”

Root and shoot initiation by leaf, stem, and storage root explants of sweet potato

“…Similar shoot bud regeneration on roots has been previously reported for a number of genera including Convolvulus [3,4,8,19], Linaria [6], Chondrilla [12], lsatis [7], Comptonia [ 10], and Ipomoea [ 11 ].…”