Effect of Multispectral Supplemental Light Containing Green Light and UV‐AB on Growth Characteristics and Antioxidant Enzyme Activities of Scions and Rootstocks in Grafted Tomato Seedling

The green light and UV‐AB spectra have been found to respectively enhance plant stress resistance. This helps plants grow better in low‐light conditions. In this study, the grafted tomato seedlings were cultured in a greenhouse under two types of supplemental lights at three light seedling distances (LSD). The growth characteristics and antioxidant enzyme activities of the grafted tomato seedlings were measured at four sampling stages. The results showed that the multispectral supplement light (1.185 μmol·m −2 ·s −1 visible light + 0.154 μmol·m −2 ·s −1 green + 0.7 μW cm −2 UV‐A + 0.2 μW cm −2 UV‐B) at 80 cm significantly increased the length, stem thickness, fresh weight, and dry weight of tomato‐grafted scions and rootstocks. Moreover, the fresh weights of scion and rootstock at 28 days of supplementary lighting increased significantly by 135.85% and 27.23%, respectively, and the grafted strong seedling index increased by 41% at 21 d of supplementary lighting. Meanwhile, the multispectral supplemental light can improve the activity of catalase (CAT) in tomato scion, and peroxidase and CAT in its rootstock at all stages. Briefly, the multispectral supplement light can effectively promote the growth of tomato‐grafted seedlings, cultivate strong seedlings, and enhance its activity of antioxidant enzymes.