Moosavi-Nezhad Moein, Salehi Reza, Aliniaeifard Sasan, Tsaniklidis Georgios, Woltering Ernst J, Fanourakis Dimitrios, Żuk-Gołaszewska Krystyna, Kalaji Hazem M
Department of Horticultural Sciences, Campus of Agriculture and Natural Resources, University of Tehran, Karaj P.O. Box 31587-77871, Iran.
Photosynthesis Laboratory, Department of Horticulture, Aburaihan Campus, University of Tehran, Tehran P.O. Box 33916-53755, Iran.
Int J Mol Sci. 2021 Jul 28;22(15):8043. doi: 10.3390/ijms22158043.
To investigate the importance of light on healing and acclimatization, in the present study, grafted watermelon seedlings were exposed to darkness (D) or light, provided by blue (B), red (R), a mixture of R (68%) and B (RB), or white (W; 35% B, 49% intermediate spectra, 16% R) LEDs for 12 days. Survival ratio, root and shoot growth, soluble carbohydrate content, photosynthetic pigments content, and photosynthetic performance were evaluated. Seedling survival was not only strongly limited in D but the survived seedlings had an inferior shoot and root development, reduced chlorophyll content, and attenuated photosynthetic efficiency. RB-exposed seedlings had a less-developed root system. R-exposed seedlings showed leaf epinasty, and had the smallest leaf area, reduced chlorophyll content, and suppressed photosynthetic apparatus performance. The R-exposed seedlings contained the highest amount of soluble carbohydrate and together with D-exposed seedlings the lowest amount of chlorophyll in their scions. B-exposed seedlings showed the highest chlorophyll content and improved overall PSII photosynthetic functioning. W-exposed seedling had the largest leaf area, and closely resembled the photosynthetic properties of RB-exposed seedlings. We assume that, during healing of grafted seedlings monochromatic R light should be avoided. Instead, W and monochromatic B light may be willingly adopted due to their promoting effect on shoot, pigments content, and photosynthetic efficiency.
为了研究光照对愈合和驯化的重要性，在本研究中，将嫁接的西瓜幼苗置于黑暗（D）或光照条件下，光照由蓝色（B）、红色（R）、R（68%）和B（RB）的混合物或白色（W；35%B、49%中间光谱、16%R）发光二极管提供，持续12天。评估了存活率、根和地上部生长、可溶性碳水化合物含量、光合色素含量和光合性能。幼苗存活率不仅在黑暗条件下受到强烈限制，而且存活的幼苗地上部和根系发育较差，叶绿素含量降低，光合效率减弱。暴露于RB的幼苗根系发育较差。暴露于R的幼苗表现出叶片向下弯曲，叶面积最小，叶绿素含量降低，光合机构性能受到抑制。暴露于R的幼苗接穗中可溶性碳水化合物含量最高，与暴露于D的幼苗一起，叶绿素含量最低。暴露于B的幼苗叶绿素含量最高，整体PSII光合功能得到改善。暴露于W 的幼苗叶面积最大，其光合特性与暴露于RB的幼苗非常相似。我们认为，在嫁接幼苗愈合过程中，应避免单色红光。相反，由于白光和单色蓝光对地上部、色素含量和光合效率有促进作用，可以欣然采用。
