In day-neutral flowering plants, such as tomato, flower induction is mainly governed by age-dependent and gibberellin pathways Silva et al. Therefore, from a flower-induction standpoint, the plant can be seen as day-neutral.
Similarly, Caryopteris and Passiflora edulis have no photoperiod requirements for flower induction but require a specific photoperiod length for flower maturation: in Caryopteris flowers, initiation does not have photoperiod requirements, but anthesis only occurs at day length shorter than 16 h Piringer et al.
Isolation and characterization of the genetic and physiological elements involved in photoperiodic development of solitary flowers will be useful for better understanding the differences between Cannabis cultivars of different origins. Photoperiod has a wide-ranging effect on plant development, e.
Photoperiod, like other environmental stimuli, regulates plant responses through internal signals that affect plant architecture. We argue that in Cannabis , a short photoperiod orchestrates intense branching of the inflorescence, with floral initiation that occurs independently of short photoperiod. Each inflorescence consisted of condensed higher-order branchlets.
The Cannabis inflorescence can be defined as a highly branched compound raceme. It is characterized by monopodial growth, with persistent apical meristem and axillary indeterminate inflorescences of higher orders Figure 6. The development of the inflorescence is acropetal and lateral racemes are produced prior to terminal flower differentiation. Differentiation of terminal flowers of racemes can be caused by mutations in the genes regulating meristematic identity Lifschitz et al.
Yet, sex reversal in cannabis involves ethylene and gibberellin signaling Sarath and Mohan Ram, Further research should examine the genetic regulation of the interplay between flower initiation and branching in the Cannabis inflorescence. Considering that the trichomes are located mainly on vegetative parts of the inflorescence Andre et al.
BS-R supervised the project and, together with SD, carried out the experiments. SD contributed to the final version of the manuscript. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The medical Cannabis cultivars were obtained from Canndoc Ltd.
The authors thank Hanita Zemach for her help with the microscopic analyses and Yael Sade for cultivating the plants and for technical assistance. National Center for Biotechnology Information , U. Journal List Front Plant Sci v.
Front Plant Sci. Published online Apr 2. Author information Article notes Copyright and License information Disclaimer. Received Jan 8; Accepted Mar 7. The use, distribution or reproduction in other forums is permitted, provided the original author s and the copyright owner s are credited and that the original publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these terms. This article has been cited by other articles in PMC. TIF 19M. Abstract The inflorescence is the main product of medical cannabis.
Keywords: cannabis, inflorescence, photoperiod, solitary flower, branching. Introduction The genus Cannabis , in the family Cannabaceae, includes annual herbaceous, dioecious species. Open in a separate window. Figure 1. Microscopy Plants of each cultivar were sampled for meristem analysis every 5—7 days. Results Growth and Development Under Long Photoperiod During growth under long photoperiod, the main shoot of the cannabis plants branched monopodially, producing alternate branching shoots Figure 2A.
Figure 2. Growth and Development Following Transition to Short Photoperiod Three weeks after rooting, young plants were moved to short photoperiod conditions Figure 3A.
Figure 3. Figure 4. Plant and Inflorescence Architecture Growth and development of the main stem were accompanied by dramatic changes in leaf morphology, with foliage leaves decreasing in size, petiole length, and lobe number Figures 5A — C.
Figure 5. Figure 6. Variability in Inflorescence Termination The three studied cultivars differed considerably in plant architecture and inflorescence structure Figures 7A — C , and termination of the apical meristem occurred in three different setups Figures 7D — F :. Figure 7. Discussion Cannabis is an annual herb cultivated by humans in almost all parts of the world, from the tropics to alpine foothills. Conflict of Interest Statement The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Acknowledgments The medical Cannabis cultivars were obtained from Canndoc Ltd. References Andre C. Cannabis sativa : the plant of the thousand and one molecules. Plant Sci. Floral initiation and inflorescence architecture: a comparative view. Interplay between chemistry and morphology in medical cannabis Cannabis sativa L. Flowering time regulation in crops—what did we learn from Arabidopsis?
Vegetative propagation of cannabis by stem cuttings: effects of leaf number, cutting position, rooting hormone, and leaf tip removal. Inflorescence development in petunia: through the maze of botanical terminology. Vancouver: Van Patten Publishing;. Chandra S. New York, NY: Springer; , 79— The control of flowering time by environmental factors. Plant J. Cannabis: Evolution and ethnobotany. Towards an ontogenetic understanding of inflorescence diversity. Sowing time and prediction of flowering of different hemp Cannabis sativa L.
Disentangling confusions in inflorescence morphology: patterns and diversity of reproductive shoot ramification in angiosperms. Preedy V. Amsterdam: Elsevier; , 3— Cannabis, from plant to pill.
Review of flowering control in industrial hemp. Fibers 9 , 23— Morphogenesis of capitate glandular hairs of Cannabis sativa Cannabaceae. Cannabis: from cultivar to chemovar II—a metabolomics approach to Cannabis classification.
Environmentally friendly gardening. Plant health. Take part in our research. Meet the team. Shop plants rhsplants. Shopping with the RHS. RHS Christmas gifts. Help us achieve our goals Make a donation. Join the RHS today and support our charity Join now. Save to My scrapbook. Pruning wisteria in winter. Quick facts. Jump to When to prune wisteria How to prune wisteria Other ways to train wisteria Problems. When to prune wisteria Wisteria is pruned twice a year, in July or August, then again in January or February.
How to prune wisteria Wisterias can be left to ramble unchecked where space allows but will usually flower more freely and regularly if pruned twice a year. Winter pruning January or February Then, cut back the same growths to two or three buds in January or February when the plant is dormant and leafless to tidy it up before the growing season starts and ensure the flowers will not be obscured by leaves.
Renovation or hard pruning With older plants severe pruning may be needed to remove old, worn-out growths, or branches growing over windows or protruding outwards from the face of the building.
Often there is strong basal shoot growth If unwanted for replacement branches they can be removed. Any such pruning can be done during the period from leaf fall to early February Other new growths can be pruned back summer and winter as for normal routine pruning. Summer pruning: New shoots that are not needed or have grown in already crowded areas should be pruned.
Cut them back to five or six leaves from the main branch, making the cut just above that leaf. Other ways to train wisteria On walls The ideal way to grow wisteria against a wall is to train it as an espalier , with horizontal support wires 3mm galvanised steel set 30cm 1ft apart. On pergolas and arches Wisterias with long flower racemes are best admired on structures where they can hang free, unimpeded by branches or foliage.
Growing into trees Wisteria can be trained to grow up into the canopy of a small tree, but to the possible detriment of the tree. Giving your plants a dose of Vitamin B complex fertilizer along with the water will help them through this beneficial but often shocking period.
The roots will benefit from this nutrient, and the plants should be higher-yielding. This vitamin fertilizer is thought to help the plants grow larger and produce bigger, more resinous colas. In the flowering stage, growers feed their plants an organic high-phosphorous fertilizer.
Vitamin B1 helps your plants take up and assimilate phosphorous. Kelp and other plants from the sea are a natural and organic source of vitamin B. Carefully pruning your cannabis will help you maximize the growth and potency of every plant. Seed variety , site selection, soil and a regulated irrigation and fertilizing schedule are the other factors that can help you pull off a harvest you can be proud of.
A little extra care and time spent pruning can pay big dividends in a big, high-quality crop. Just ask any dedicated gardeners or growers, and they will tell you about the dedication and nurturing required and the ultimate payoff.
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