Physiological analysis and heat-resistant protein (LEA) activity in squash hybrid seeds during development

This study has aimed to evaluate the best time to harvest squash seeds and verify the effect of fruit storage on protein activity and in the physiological quality of 'Jabras' squash hybrid seeds. The fruits were harvested at 15, 30, 45, 60 and 75 days after anthesis (DAA). In every period, thirty fruits were harvested and fifteen had their fruit extracted immediately after harvesting, and the other fifteen fruits were stored for twenty days in plastic boxes under shade conditions, and only after this period the seeds were extracted. Seed quality was evaluated for the following parameters: moisture content, germination, first count, germination rate, seedling emergence, emergence rate, seed mass and seedling dry matter. Also, the electrophoretic profile analysis of heat-resistant proteins (Late Embryogenesis Abundant - LEA) was performed. Seed physiological maturity occurred in fruits harvested at 60 days after anthesis and stored for 20 days. During this period, seeds reached the maximum dry matter, maximum germination and vigor, and a high concentration of LEA proteins.

本研究旨在明确南瓜种子的最佳采收时期，并验证果实贮藏对‘Jabras’杂交南瓜种子蛋白质活性及生理品质的影响。试验以开花后天数（days after anthesis, DAA）的15、30、45、60和75 d为五个采收时段，每个时段采收30个果实：其中15个于采收后即刻脱取种子，剩余15个果实置于遮光塑料盒中贮藏20 d后再脱籽。本研究对种子品质开展了多参数检测，包括含水量、发芽率、初次计数（发芽势）、发芽速率、出苗率、出苗速率、种子重量及幼苗干物质含量；同时还进行了耐热蛋白——胚胎发育晚期丰富蛋白（Late Embryogenesis Abundant - LEA）的电泳图谱分析。结果显示，种子生理成熟期对应开花后60 d采收并贮藏20 d的果实，此条件下种子的干物质积累量、发芽率与活力均达到最大值，且LEA蛋白浓度达到最高水平。