PERICARP, LEACHATE, AND CARBOHYDRATE INVOLVEMENT IN THERMOINHIBITION OF GERMINATING SPINACH SEEDS
PERICARP, LEACHATE, AND CARBOHYDRATE INVOLVEMENT IN THERMOINHIBITION OF GERMINATING SPINACH SEEDS
复制标题
果皮、渗滤液和碳水化合物对发芽菠菜种子热抑制的影响
DOI：
10.21273/jashs.124.3.301
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发表时间：
1999
影响因子：
1.9
通讯作者：
H. Belefant
中科院分区：
文献类型：
--
作者：
D. Leskovar;V. Esensee;H. Belefant
高温会抑制菠菜（Spinacia oleracea L.）种子的发芽。了解菠菜的热抑制对于预测发芽和出苗事件至关重要。本研究的目的有 3 个：1) 确定菠菜基因型“Cascade”、“ACX 5044”、“Fall Green”和“ARK 88-354”暴露在恒定和交替温度下的种子发芽率和发芽率； 2) 确定果皮抑制的性质和程度； 3) 研究渗滤液和寡糖在热抑制中的作用。发芽抑制在>20°C 恒温时开始，并在35°C 时被完全抑制。 30/15 °C（白天 12 小时/夜晚 12 小时）的交替温度比恒定 30 °C 的发芽率更高。基因型对超优温度的敏感性按“ARK 88-354”≤“秋绿”“秋绿”>“级联”的顺序排列。吸胀 48 小时后，“ARK 88-354”和“Fall Green”种子中的蔗糖和葡萄糖水平最高，棉子糖水平最低，而“Cascade”种子的代谢活性仍然较低。这些数据表明，果皮显然充当了物理屏障以及热抑制过程中的抑制剂来源。和法兰特，1995）。种子萌发期间碳水化合物发生变化，通常单糖含量增加，寡糖含量减少（Vertucci 和 Farrant，1995；Koster 和 Leopold，1988）。较高聚合度（DP）的寡糖可以保护种子中的膜和大分子免受干燥损伤（Bernal-Lugo 和 Leopold，1992）。缺乏在超最佳温度下吸收的菠菜种子中碳水化合物代谢的证据，以及较高DP的寡糖（例如蔗糖和棉子糖）在防止热抑制种子进入热休眠中的作用的证据。本研究的目的是确定四种菠菜基因型种子热抑制的程度、果皮和种皮浸出液所施加的抑制的性质和水平，并确定和量化热抑制期间可溶性碳水化合物的水平。
Spinach (Spinacia oleracea L.) seed germination can be inhibited by high temperatures. An understanding of thermoinhibition in spinach is critical in predicting germination and emergence events. The purpose of this study was 3-fold: 1) to determine seed germination percentage and rate of spinach genotypes—'Cascade', 'ACX 5044', 'Fall Green', and 'ARK 88-354'—exposed to constant and alternating temperatures; 2) to determine the nature and extent of inhibition imposed by the pericarp; and 3) to investigate leachate and oligosaccharide involvement in thermoinhibition. Germina- tion inhibition began at >20 °C constant temperature and was totally suppressed at 35 °C. Alternating temperatures at 30/15 °C (12-hour day/12-hour night) resulted in greater germination than a constant 30 °C. The genotype sensitivity to supraoptimal temperatures was in the order of 'ARK 88-354' ≤ 'Fall Green' 'Fall Green' > 'Cascade'. After 48 hours of imbibition, sucrose and glucose levels were highest and raffinose levels were lowest in 'ARK 88-354' and 'Fall Green' seeds, while 'Cascade' seeds remained less active metabolically. These data suggest that the pericarp apparently acts as a physical barrier as well as a source of inhibitors during thermoinhibition. and Farrant, 1995). Changes in carbohydrates occur during seed germination, with generally the monosaccharide content increas- ing and the oligosaccharide content decreasing (Vertucci and Farrant, 1995; Koster and Leopold, 1988). Oligosaccharides of higher degree polymerization (DP) may protect membranes and macromolecules in seeds from desiccation damage (Bernal-Lugo and Leopold, 1992). Evidence of carbohydrate metabolism in spinach seeds imbibed at supraoptimal temperatures is lacking, as well as the role of oligosaccharides of higher DP, such as sucrose and raffinose, in preventing thermoinhibited seeds going into thermodormancy. The purpose of this study was to determine the extent of seed thermoinhibition in four spinach genotypes, the nature and level of inhibition imposed by the pericarp and seedcoat leachates, and to identify and quantify the level of soluble carbohydrates during thermoinhibition.