Structure of Solanum dulcamara L. (Solanaceae) semishrub monocarpic shoots

In the preface the history of investigation of methodological basis for separation and description of structure functional zones of monocarpic shoots of plants is briefly analyzed. Basic zones described so far are defined. The meaning of these zones is shown. In the section "Material and methods of research" the object of study (Solanum dulcamara L.) is defined. Systematical location, geographical distribution and ecological characteristics of the plant are described. The presence of threeecobiomorphes in this species (subshrub, vine and prostrate shrub) is shown. Locations of the material collection (Kirov and Yaroslavl region; herbariums LE, MHA, SYKO, IBIW, TK, NS, NSK, MOSP, SYKT) and methods of its processing are characterized.Seasonal development of S. dulcamara shoot axis is shown in the basic part of the article. Three types of monocarpical shoots that are present in the structure of sympodial axis are marked out on these grounds: 1) shoot of n level developing from bud of regular renewal; 2) shoots of n+1 and next level of branching developing from axillary buds on present year shoots; 3) shoots of final level of branching developing from top axillary buds of final shoot of present year.The full development of monocarpic shoots is defined. Four phases are marked out in shoot development of the first type (bud, vegetative assimilated shoot, vegetative & generative shoot, shoot of secondary activity with three subphases - secondary vegetative assimilated shoot, overground rezid, underground rezid). Five phases are marked out in shoots of the second type (the same as the first type's phases). Three phases are marked out in shoots of the third type (phase "shoot secondary activity" is absent).Coming from ideas of W. Troll (1964) in such monocarpic shoots the same structure functional zones are determined: 5 zones in shoots of the first type; 1 zones in shoots of the second type; 2 zones in shoots of the third type. Formulas of shoots' structure for each type are compiled: first type: lower inhibition zone - innovation zone - middle inhibition zone - amplification zone - zone of main inflorescence; second type: inhibition zone - innovation zone - zone of main inflorescence; third type: innovation zone - zone of main inflorescence.It is shown that monocarpic shoots of S. dulcamara are distinguished from each other by the number of metamers, the number and the duration of phases of full development of shoots and their structure functional zones. Probably, this fact should be regarded as adaptation to conditions of seasonal climate, and the structure - as the synflorescence according to W. Troll (1964).

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