ARBUSCULAR MYCORRHIZAL INOCULATION AND SHADING ENHANCE CROP PERFORMANCE AND QUALITY OF GREENHOUSE Begonia semperflorens

Mycorrhizal fungi are gaining interest in the floriculture sector due to the beneficial effects on a crop performance and ornamental quality. The aim of the current study was to assess the effect of inoculation with the arbuscular mycorrhizal (AM) fungi Rhizophagus irregularis on ornamental quality of Begonia × semperflorens-cultorum grown in two different protected cultivation systems: a shadehouse or glasshouse. The inoculated plants incurred a significant increase of plant height by 34.6%, lateral shoot length by 27.9%, number of lateral shoots by 41.2%, number of flowers per plant by 102.9%, flower diameter by 27.5%, and stems dry weight by 263.6%. High temperatures in the glasshouse negatively affected the AM root colonization. On the contrary, shading induced higher mycorrhizal colonization (48.6%) and increased plant height, number of lateral shoots, number of flowers per plant and flower diameter compared to the glasshouse environment. Taking all together, our results clearly demonstrated that mycorrhizal inoculation at transplanting and shading may be beneficial to floriculture growers wishing to produce high quality B. semperflorens-cultorum plants during the spring-summer season.

Reactive Oxygen Species Acts as an Important Inducer in Low-temperature-induced Anthocyanin Biosynthesis in Begonia semperflorens

Leaves of Begonia semperflorens accumulate anthocyanins and turn red under low temperature (LT). In the present work, LT increased H2O2 content and superoxide anions production rate, causing significant increases in the activities of enzymes and contents of reduced components involved in the ascorbate-glutathione cycle (AsA-GSH cycle). As a result, LT-exposed seedlings increased the expression of genes involved in anthocyanin biosynthesis, and accumulated anthocyanin. Based on LT condition, application of N,N'-dimethylthiourea (DMTU) decreased reactive oxygen species (ROS) content, and unbalanced the AsA-GSH-controlled redox homeostasis. As a result, seedlings in the LT + DMTU group did not accumulate anthocyanin. Our results suggest that ROS may act as an important inducer in LT-induced anthocyanin biosynthesis.