Articles
Mechanism of light for the production of grafted watermelon seedlings
Article number
1453_15
Pages
109 – 114
Language
English
Abstract
Watermelon is among the most important vegetable crops in terms of economic value.
Throughout the world, watermelons are mainly established through grafted seedlings due to a number of factors.
The production of grafted seedlings can be grouped in three stages: firstly the cultivation of scion and rootstock seedlings, secondly the healing of grafted seedlings, and thirdly the acclimatization of healed grafted seedlings.
All stages take place indoors during winter or early spring when light quantity is insufficient.
Our objective was to obtain a cultivation protocol of grafted watermelon seedlings’ production for all three stages mentioned above using artificial lighting.
In the first stage, seedlings to-be-grafted were grown in a greenhouse under supplemental high-pressure sodium (HPS) lamps or 12% blue/88% red (12B/88R) light-emitting diodes (LEDs) with 18-h photoperiod and 90±10 μmol m‑2 s‑1. Important morphological (stem diameter, leaf area) and biomass (above- and underground) factors were enhanced under 12B. In the following stage of healing, grafted seedlings were treated with LEDs emitting various red/blue compositions in a chamber with controlled conditions (18-h photoperiod and 85±10 μmol m‑2 s‑1, 25°C, 93-99% relative humidity). Initially, blue light promoted vascular reconnection, while afterwards red light enhanced the development and molecular profile of the grafted seedlings.
Moreover, internal plant growth regulators participated in a varying signaling cascade depending on the light environment.
During acclimatization, the experimental set-up was similar to the first stage.
Indeed, 12B promoted physiological attributes and root growth, which is crucial for the subsequent plant growth post-transplantation.
Overall, LEDs proved beneficial for the production of seedlings to-be-grafted as well as for acclimatization of grafted seedlings in the greenhouse.
In the stage of healing it was shown that even small interplays in the light spectra triggers a significant effect in plant behaviour.
Throughout the world, watermelons are mainly established through grafted seedlings due to a number of factors.
The production of grafted seedlings can be grouped in three stages: firstly the cultivation of scion and rootstock seedlings, secondly the healing of grafted seedlings, and thirdly the acclimatization of healed grafted seedlings.
All stages take place indoors during winter or early spring when light quantity is insufficient.
Our objective was to obtain a cultivation protocol of grafted watermelon seedlings’ production for all three stages mentioned above using artificial lighting.
In the first stage, seedlings to-be-grafted were grown in a greenhouse under supplemental high-pressure sodium (HPS) lamps or 12% blue/88% red (12B/88R) light-emitting diodes (LEDs) with 18-h photoperiod and 90±10 μmol m‑2 s‑1. Important morphological (stem diameter, leaf area) and biomass (above- and underground) factors were enhanced under 12B. In the following stage of healing, grafted seedlings were treated with LEDs emitting various red/blue compositions in a chamber with controlled conditions (18-h photoperiod and 85±10 μmol m‑2 s‑1, 25°C, 93-99% relative humidity). Initially, blue light promoted vascular reconnection, while afterwards red light enhanced the development and molecular profile of the grafted seedlings.
Moreover, internal plant growth regulators participated in a varying signaling cascade depending on the light environment.
During acclimatization, the experimental set-up was similar to the first stage.
Indeed, 12B promoted physiological attributes and root growth, which is crucial for the subsequent plant growth post-transplantation.
Overall, LEDs proved beneficial for the production of seedlings to-be-grafted as well as for acclimatization of grafted seedlings in the greenhouse.
In the stage of healing it was shown that even small interplays in the light spectra triggers a significant effect in plant behaviour.
Authors
F. Bantis, C. Dangitsis, T. Koufakis, D. Kintzonidis, A. Koukounaras
Keywords
Citrullus lanatus, transplants, light-emitting diodes, LED, controlled environment agriculture
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