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Abstract: Chilling injury occurs in loquat (Eriobotrya japonica Lindl. cv. Luoyangqing) fruit when they are stored at temperatures lower than 5°C. In attempts to reduce this chilling injury, the effect of low temperature conditioning (LTC) was examined. Loquat fruit were conditioned at 5°C for 6 days before 0°C storage for up to 54 days. Control fruit stored at 0°C exhibited severe symptoms of lignification and tissue browning, and a decrease in percentage juice. LTC treatment significantly reduced these chilling injury symptoms, and doubled storage life. In terms of acceptability (tissue browning, internal browning (IB) index <0.4; fruit decay, <10%; flesh firmness, <6.0N; percentage juice, >60%), fruit could only be stored for 40 days at 0°C with a 3 days shelf life at 20°C, while LTC fruit could be stored for 60 days at 0°C with a similar shelf life. Similarly, LTC fruit could be stored for 40 days with a 5 days shelf life at 20°C, while fruit could be only stored for 20 days at 0°C with a 5 days shelf life. Our results confirm that LTC can effectively alleviate postharvest chilling injury of loquat fruit and may provide longer storage life with acceptable external and internal quality. [Copyright &y& Elsevier]

Abstract: Four expansin cDNA fragments, EjEXPA1, EjEXPA2, EjEXPA3 and EjEXPA4, were isolated and characterized from loquat (Eriobotrya japonica Lindl.) fruit. EjEXPA1 mRNA accumulated consistently with the increase in fruit firmness in 0°C storage of ‘Luoyangqing’ (LYQ) fruit, where chilling injury with increased fruit firmness due to lignification was observed. EjEXPA1 mRNA levels were lower in fruit that underwent low temperature conditioning (LTC, 6d at 5°C then 4d at 0°C), and in 1-methylcyclopropene (1-MCP) treated fruit, in both cases where chilling injury was alleviated. Fruit of the ‘Baisha’ (BS) cultivar soften after harvest rather than increase in firmness, and high expression levels of EjEXPA1 and EjEXPA4 accompanied the softening of BS fruit stored at 20°C; such mRNA accumulation was much lower when fruit were stored at 0°C, where softening was significantly inhibited by the low temperature. Very low expression of EjEXPA2 and EjEXPA3 was observed during storage of both LYQ and BS fruit under the different storage conditions. Our results showed that of the four genes characterized, EjEXPA1 might be associated with chilling-induced lignification while both EjEXPA1 and EjEXPA4 were closely related to softening of loquat fruit during the postharvest period. [Copyright &y& Elsevier]