干燥对2种栗属(Castanea)种子发芽率及水分状态的影响  

Effect of Drying on Germination and Moisture State of Two Species of Chestnuts(Castanea)

作　　者：亢涵[1] 龚治宇 梁赋 覃潜 陆毕懿 刘宝林[1] KANG Han;GONG Zhi-yu;LIANG Fu;QIN Qian;LU Bi-yi;LIU Bao-in(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093

出　　处：《包装工程》2023年第7期96-103,共8页Packaging Engineering

基　　金：国家自然科学基金(31750110474,32001119)。

摘　　要：目的探究栗属种子的脱水敏感性,并研究干燥过程对胚轴水分状态的影响。方法以采自河南的野生板栗和茅栗为实验材料,室温下在密闭容器中用硅胶快速干燥2种新鲜栗子,分别测定其干燥不同时间后水分含量和发芽率的变化并剥取胚轴。基于差式扫描量热技术(DSC),分析所取胚轴的热力学特征,并根据胚轴含水量和对应热焓值计算可冻结水与非冻结水的占比。结果板栗干燥8 d时,水分含量由49.51%降至32.97%,发芽率从78.33%降至8.5%;茅栗干燥4 d时,水分含量由41.24%降至30.82%,发芽率从71.65%降至9.33%。种子水分含量低于30%时仅有少数种子发芽。DSC分析显示,实验过程中随着干燥时长的增加,胚轴的水分含量显著下降且与结晶/熔融阶段的起始温度、峰值温度和热焓值呈显著正相关。板栗的可冻结水分含量由89%降至7.9%,茅栗的可冻结水分含量由81%降至2.7%。结论野生板栗和茅栗有极强的干燥敏感性,属典型顽拗性种子,其发芽率受水分含量高度影响,其胚轴的热物性参数和水分状态也与干燥程度密切相关。The work aims to investigate the desiccation sensitivity of chestnut(castanea)seeds and study the effect of drying process on the moisture state of the embryonic axis.Samples were wild chestnuts of castanea mollossoma and castanea sequinii harvested in Henan Province.Two species of fresh chestnuts were rapidly dried with silica gel in airtight containers at room temperature and the moisture content(MC)and the germination were determined after different drying duration.Then,the embryonic axis was peeled off.Based on differential scanning calorimetry(DSC),the thermodynamic characteristics of the embryonic axis were analyzed.Afterward,the proportions of freezable water and non-freezable water were calculated as per MC and corresponding enthalpy of the embryonic axis.MC of C.mollossoma decreased from 49.51%to 32.97%after 8 days of drying,with a dropdown of germination from 78.33%to 8.5%.On the other hand,a smooth descent in MC of C.sequinii was reflected from 41.24%to 30.82%after 4 days of drying,with a similar curve of germination falling from 71.65%to 9.33%.Only a few seeds germinated when the MC was lower than 30%.According to the analysis of DSC,as drying duration prolonged,the MC of embryonic axis kept decreasing significantly and was positively correlated with onset temperature,peak temperature,and enthalpy of crystallization/melting stage.The proportion of freezable moisture in embryonic axis substantially reduced from 89%to 7.9%in C.mollossoma and an analogous trend happened in C.sequinii from 81%to 2.7%.Both C.mollossoma and C.sequinii of wild chestnuts are obviously-changeable on desiccation sensitivity.They are also typically recalcitrant seeds with germination rate highly affected by MC.Besides,the thermophysical parameters and moisture state of embryonic axis are also closely related to the degree of drying.

关 键 词：栗属 顽拗性种子 干燥敏感性 热力学分析 水分状态 

分 类 号：S375[农业科学—农产品加工]