PDF(Pubmed)
Abstract：
Postharvest fibrosis and greening of Toona sinensis buds significantly affect their quality during storage. This study aimed to clarify the effects of low-temperature storage on postharvest red TSB quality harvested in different seasons. Red TSB samples were collected from Guizhou province, China, 21 days after the beginning of spring (Lichun), summer (Lixia), and autumn (Liqiu), and stored at 4 °C in dark conditions. We compared and analyzed the appearance, microstructure, chlorophyll and cellulose content, and expression levels of related genes across different seasons. The results indicated that TSB harvested in spring had a bright, purple-red color, whereas those harvested in summer and autumn were green. All samples lost water and darkened after 1 day of storage. Severe greening occurred in spring-harvested TSB within 3 days, a phenomenon not observed in summer and autumn samples. Microstructural analysis revealed that the cells in the palisade and spongy tissues of spring and autumn TSB settled closely during storage, while summer TSB cells remained loosely aligned. Xylem cells were smallest in spring-harvested TSB and largest in autumn. Prolonged storage led to thickening of the secondary cell walls and pith cell autolysis in the petioles, enlarging the cavity area. Chlorophyll content was higher in leaves than in petioles, while cellulose content was lower in petioles across all seasons. Both chlorophyll and cellulose content increased with storage time. Gene expression analysis showed season-dependent variations and significant increases in the expression of over half of the chlorophyll-related and cellulose-related genes during refrigeration, correlating with the observed changes in chlorophyll and cellulose content. This research provides valuable insights for improving postharvest storage and freshness preservation strategies for red TSB across different seasons.
摘要：
采后纤维化和绿芽显著影响其贮藏品质。本研究旨在阐明低温贮藏对不同季节采后红TSB品质的影响。红色TSB样本来自贵州省，中国,开春（立春）后21天，夏天（丽夏），和秋天（立秋），并在黑暗条件下在4°C下储存。我们比较和分析了外观，微观结构，叶绿素和纤维素含量，以及不同季节相关基因的表达水平。结果表明，春季收获的TSB具有明亮的，紫红色,而夏天和秋天收获的是绿色的。所有样品在储存1天后失水并变暗。春季收获的TSB在3天内发生了严重的绿化，在夏季和秋季样品中没有观察到的现象。微观结构分析表明，春季和秋季TSB的栅栏和海绵状组织中的细胞在储存过程中紧密沉降，而夏季TSB细胞保持松散排列。木质部细胞在春季收获的TSB中最小，在秋季最大。长时间储存导致叶柄次生细胞壁增厚和髓细胞自溶，扩大空腔面积。叶片中的叶绿素含量高于叶柄，而纤维素含量在所有季节的叶柄中都较低。叶绿素和纤维素含量均随贮藏时间增加。基因表达分析显示，在冷藏过程中，超过一半的叶绿素相关和纤维素相关基因的表达呈季节依赖性变化和显着增加，与观察到的叶绿素和纤维素含量变化相关。这项研究为改善不同季节红色TSB的采后储存和保鲜策略提供了有价值的见解。
