Shoot-Formation Model as a Basis for Adaptations of Flowering Plants

Clematis (Clematis ×hybrida) is among the flowering plants well-recognized by the retail consumer; however, production has not traditionally fit into standard greenhouse production systems. One reason is the relatively long 2-year production cycle from propagation to flowering. Four experiments were conducted with clematis ‘H.F. Young’ to understand the factors that influence shoot development and flowering of clematis so that strategies could be developed for bulking, providing a cold treatment, and flowering the plants with a shortened production time. The first experiment showed an increase in shoot and flower numbers and a decrease in time to flower as the duration of cold treatment increased from 0 to 9 weeks and the photoperiod increased from 9 to 16 hours. The second experiment resulted in greater shoot and flower numbers when plants were forced at 21 °C as compared with 27 °C. The third experiment showed that the application of ethephon (500 or 1000 mg·L−1) during bulking increased shoot formation (branching) as compared with the control or 500 mg·L−1 benzylaminopurine treatments. The fourth experiment showed that applications of 500 mg·L−1 ethephon along with a 16-hour photoperiod during the bulking period improved shoot number and flowering of the finished crop. The combined results provide guidelines for producing a well-branched, flowering clematis crop within 1 year from the start of propagation to the time of the first open flower.

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Shoot formation model (architectural model) Phlomoides oreophila

BIO Web of Conferences ◽

10.1051/bioconf/20202400038 ◽

2020 ◽

Vol 24 ◽

pp. 00038

Author(s):

Elizaveta K. Komarevtseva ◽

Alexandra A. Guseva

Keyword(s):

Morphological Characteristics ◽

Growth Period ◽

Inhibition Zone ◽

Shoot Formation ◽

Altai Mountains ◽

Formation Model ◽

Apical Bud ◽

Spring Generation ◽

Functional Zones ◽

Spring Leaf

The morphological characteristics of Phlomoides oreophila, which grows in the Altai Mountains and Southeast Kazakhstan, are given. It is established that the species belongs to the monopodial-rosette model of shoot formation. The main structural unit is a perennial basal (skeletal) rosette shoot. Its annual growths form an epigeogenic oblique-orthotropic rhizome. An elementary shoot appears during 1 growth period and carries the vegetative and generative parts. The formula of the functional zones of the elementary shoot is determined: the inhibition zone → [innovation zone] → amplification zone → apical bud. It was established that the boundaries of the elementary and annual shoots do not coincide. Elementary shoot includes spring leaf generation (inhibition zone), summer leaf generation with axillary vegetative buds (innovation zone) and vegetative-generative buds (amplification zone). Vegetative-generative shoots appear only after wintering the following spring. They are located below the rosette leaves of the spring generation (this is the beginning of a new elementary shoot). As a result, the annual shoot includes the elementary shoot of the current year, as well as the amplification zone of the elementary shoot of last year.

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