脱水方法对棕榈种子萌发及膜脂过氧化的影响

Influence of Dehydration Methods on Germination of Trachycarpus fortunei Seeds and Peroxidation of Their Membrane of Lipid

以棕榈种子为材料,比较了硅胶脱水和自然脱水方法下种子萌发特征和膜脂过氧化程度。结果表明:棕榈种子的初始含水量为33.1%,萌发率为83.3%;当硅胶脱水至含水量21.2%时萌发率为80.0%,而自然脱水至23.2%时萌发率仅为56.7%;当含水量降至10%左右时,硅胶脱水萌发率为27.7%,而自然脱水的萌发率为26.7%。在脱水过程中,2种脱水处理种子的浸出液电导率和丙二醛(MDA)含量都呈升高趋势,但自然脱水种子浸出液电导率升高的速率较硅胶脱水快,而MDA含量在硅胶脱水下增加较大。硅胶脱水处理种胚中脯氨酸含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性均较自然脱水高,但2种脱水处理种子整体均呈先增加再下降的趋势。研究发现,棕榈种子为中间型种子,其在脱水初期对自然脱水较敏感,而脱水后期脱水速率对其生活力影响较小;棕榈种子对硅胶脱水的脱水敏感较自然性脱水要低,硅胶脱水有利于改善棕榈种子的贮藏寿命。

With Trachycarpus fortunei seeds as materials,this paper focused on influence of silica gel dehydration and natural dehydration on their dehydration sensibility and peroxidation of their membrane of lipid.The results showed that the initial water content for T.fortunei seeds was 33.1%,and their germination rate was 83.3%.The germination rate was 80.0% when water content was 21.2% by means of silica gel dehydration,while the germination rate was only 56.7% when water content was 23.2% with natural dehydration.When water content was decreased to about 10%,germination rate with gel dehydration was 27.7%,while 26.7% with natural dehydration.It proved that T.fortunei seeds belonged to an intermediate type,and were relatively sensitive to natural dehydration in the initial stage of dehydration,while dehydration speed had little influence on their vitality.During dehydration,there was a rising tendency on electrical conductivity of lixivium and malondialdehyde（MDA） content;For seeds with natural dehydration,their electrical conductivity of lixivium had a faster rising tendency than that of gel dehydration,while content of MDA increased greatly under gel dehydration.The content of proline,activities of superoxide dismutase（SOD）,catalase（CAT） and peroxidase（POD） and ascorbic acid peroxidase（APX） in embryo of seeds with gel dehydration were higher than those with natural dehydration,but with the tendency of increase first,and decrease later.Compared with influence of dehydration speed on seeds activity under these two kinds of dehydration rate,sensitivity of gel dehydration was lower than the one of natural dehydration.Therefore,gel dehydration was helpful for improving storage life of T.fortunei seeds.