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Blueberries are rich in a variety of functional substances and have high nutritional and health values, but they are not resistant to decline during fresh storage. Here, the effects of six Bacillus species on the storage quality of, and antioxidant levels in, the southern highbush blueberry 'O'Neal' fruit were investigated. Bacillus treatments reduced the fruit decay rate, slowed fruit quality decline, inhibited malondialdehyde accumulation, and increased superoxide dismutase and peroxidase activity levels. Bacillus altitudinis Y-14 had the best effect overall. Furthermore, the effects of 1-methylcyclopropene (1-MCP), B. altitudinis Y-14, and 1-MCP + B. altitudinis Y-14 treatments on the storage quality and antioxidant of rabbiteye blueberry 'Brightwell' fruit were investigated, and each treatment effectively reduced the decay rate and weight loss of fruit. When stored for 25 days, the decay rate of the 1-MCP + B. altitudinis Y-14 group was only 8.33%, significantly lower than that of the control. The three treatments delayed the decline in fruit quality, inhibited malondialdehyde accumulation, and increased superoxide dismutase and peroxidase activity levels. The 1-MCP + B. altitudinis Y-14 treatment was more conducive to prolonging the postharvest storage period of blueberries and had the best effect in delaying the decline in fruit quality. Thus, combined 1-MCP and B. altitudinis Y-14 treatment may be an effective way to improve the storage quality and extend the storage period of blueberries, which provides a new way for storing and transporting blueberries to reduce costs and improve economic benefits. [ABSTRACT FROM AUTHOR]

To further clarify the impact of different rootstocks in grafted blueberry, fruit quality, mineral contents, and leaf gas exchange were investigated in 'O'Neal' blueberry (Vaccinium corymbosum) grafted onto 'Anna' (V. corymbosum) (AO), 'Sharpblue' (V. corymbosum) (SO), 'Baldwin' (V. virgatum) (BO), 'Plolific' (V. virgatum) (PO), and 'Tifblue' (V. virgatum) (TO) rootstocks and own-rooted 'O'Neal' (NO), and differences in anatomic structures and drought resistance were determined in AO, TO, and NO. The findings revealed that fruit quality in TO and PO was excellent, that of BO and SO was good, and that of AO and NO was medium. 'Tifblue' and 'Plolific' rootstocks significantly increased the levels of leaf phosphorus and net photosynthetic rate of 'O'Neal', accompanied by a synchronous increase in their transpiration rates, stomatal conductance, and intercellular CO2. Additionally, the comprehensive evaluation scores from a principal component analysis based on anatomic structure traits from high to low were in the order TO > AO > NO. The P50 (xylem water potential at 50% loss of hydraulic conductivity) values of these grafted plants descended in the order NO > AO > TO, and the branch hydraulic conductivity of TO and sapwood hydraulic conductivity of TO and AO were significantly lower than those of NO. Thus, TO plants exhibited the strongest drought resistance, followed by AO, and NO, and this trait was related to the effects of different rootstocks on the fruit quality of 'O'Neal' blueberry. These results provided a basis for a deeper understanding of the interaction between rootstocks and scions, as well mechanisms to improve blueberry fruit quality. [ABSTRACT FROM AUTHOR]

BACKGROUND: In general, fruit that develops from early-opening flowers ripens earlier than fruit from late-opening flowers. However, the opposite has been observed in the rabbiteye blueberry cultivar "Brightwell" (Vaccinium ashei). OBJECTIVE: From the differences of endogenous hormones and mineral nutrition, with attempt to analyze the reasons for fruit from late-opening flowers on lateral racemes of "Brightwell" ripened earlier than fruit from early-opening flowers on terminal racemes. RESULTS: Fruit from late-opening flowers on lateral racemes of "Brightwell" ripened earlier than fruit from early-opening flowers on terminal racemes. This may be associated with the higher levels of giberellin 1, abscisic acid (ABA), salicylic acid, jasmonic acid, phosphorus, iron and boron in the early developmental stages, and the higher ABA level and lower giberellin 9 level in the fruit ripening stages on lateral racemes, compared with on terminal racemes. However, the fruit borne on the terminal racemes of "O'Neal" grew faster than fruit borne on lateral racemes, this may be correlated with the higher IAA, iron, manganese, zinc and boron levels, and the lower ABA level, in the early fruit developmental stages on terminal racemes, compared with on lateral racemes. CONCLUSIONS: The growth and ripening differences in fruit set at the two positions of the two blueberry cultivars may be associated with hormonal and nutritional control during fruit development. [ABSTRACT FROM AUTHOR]

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Flowering and fruit set are important traits affecting fruit quality and yield in rabbiteye blueberry (Vaccinium ashei). Intense efforts have been made to elucidate the influence of vernalization and phytohormones on flowering, but the molecular mechanisms of flowering and fruit set remain unclear. To unravel these mechanisms, we performed transcriptome analysis to explore blueberry transcripts from flowering to early fruit stage. We divided flowering and fruit set into flower bud (S2), initial flower (S3), bloom flower (S4), pad fruit (S5), and cup fruit (S6) based on phenotype and identified 1,344, 69, 658, and 189 unique differentially expressed genes (DEGs) in comparisons of S3/S2, S4/S3, S5/S4, and S6/S5, respectively. There were obviously more DEGs in S3/S2 and S5/S4 than in S4/S3, and S6/S5, suggesting that S3/S2 and S5/S4 represent major transitions from buds to fruit in blueberry. GO and KEGG enrichment analysis indicated these DEGs were mostly enriched in phytohormone biosynthesis and signaling, transporter proteins, photosynthesis, anthocyanins biosynthesis, disease resistance protein and transcription factor categories, in addition, transcript levels of phytohormones and transporters changed greatly throughout the flowering and fruit set process. Gibberellic acid and jasmonic acid mainly acted on the early stage of flowering development like expression of the florigen gene FT, while the expression of auxin response factor genes increased almost throughout the process from bud to fruit development. Transporter proteins were mainly associated with minerals during the early flowering development stage and sugars during the early fruit stage. At the early fruit stage, anthocyanins started to accumulate, and the fruit was susceptible to diseases such as fungal infection. Expression of the transcription factor MYB86 was up-regulated during initial fruit development, which may promote anthocyanin accumulation. These results will aid future studies exploring the molecular mechanism underlying flowering and fruit set of rabbiteye blueberry. [ABSTRACT FROM AUTHOR]