ISSN:
1573-5036
Keywords:
2,4-dichlorophenoxyacetate
;
para-nodule
;
Rhizobium trifolii
;
structure
;
Triticum aestivum L.
;
wheat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Nodular outgrowths (para-nodules or p-nodules) on the roots of wheat (Triticum aestivum L.) cv. Miskle seedlings were induced by treatment with 0.3 and 0.6 mg L-1, 2,4-dichlorophenoxyacetate (2,4-D). When co-inoculated with Rhizobium trifolii strain ATCC 14480, more p-nodules were formed at these levels and p-nodulation occured at 0.1 mg L-1 indicating that inoculation enhances 2,4-D-induced p-nodulation. Similar to lateral roots, the p-nodules arose from the pericycle opposite the phloem tissues and were free from the cortical cells of the parental root at all stages of development. Structurally, the p-nodules exhibited tissue differentiation. They possessed a highly organized central vascular cylinder connected to that of the parent root, an endodermis, a cap, and an apical and lateral meristems. P-nodules formed by 2,4-D treatment alone were irregularly lobed due to uncoordinated activity of the apical meristem, while those in the combined 2,4-D and inoculation treatment were more globose. The results of the present study indicate that the 2,4-D-induced wheat p-nodules are modified lateral roots, the structure of which is enhanced by rhizobial inoculation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00038755
