西瓜超干种子的长期耐藏性分析

采用硅胶干燥的方法对‘皖杂一号’和‘丰收2号’西瓜品种的种子进行超干贮藏试验,几种不同干燥水平处理的种子在室温条件下历经了23年的密闭贮藏,种子含水量分别降至2.32%和2.23%时,发芽率分别为96%和91%。种子发芽率的高低与其含水量呈显著负相关;过氧化物酶(POD)活性、干种子种胚蔗糖含量与发芽率的变化呈正相关,而超氧化物歧化酶(SOD)活性与发芽率的变化呈负相关。比较‘皖杂一号’超干贮藏9、15、20和23年后种子发芽率变化发现,当种子含水量≥5.22%,随着贮藏时间的延长,发芽率下降较快;种子含水量在1.65%~4.12%,发芽率下降缓慢,经20~23年密闭贮藏后仍保持较高的发芽率。本试验结果表明,二倍体西瓜种子在超干条件下贮藏可以长期保持良好的生活力。

Analysis of Long Term Storability of Diploid Watermelon Ultra-dry Seeds

Watermelon (Citrullus vulgaris Schrad.) seeds of two diploid varieties,Wanza 1 and Fengshou 2,were pre-dried at different levels of silica gel and then stored for 23 years under room temperature and hermetic conditions.The best storage treatments had 96％ and 91％ germination percentage for Wanza 1 and Fengshou 2 varieties when the seed water content was adjusted at 2.32％ and 2.23％ respectively.The germination-ability of the seed was negatively correlated with the seed water content during storage period.Positive correlations were found between both POD activity and sucrose content with the germination percentage,but SOD activity showed a negative correlation with the germination percentage.In addition,the viability of Wanza 1 of each treatment were compared after 9,15,20 and 23 years of storage.For the seed with water content of 5.22％ or higher,the germination percentage declined quickly.However,seed water content with range of 1.65％ and 4.12％,the germination percentage were well retained after 20-23 years of storage.These results suggest that diploid watermelon seeds can retain high viability under ultra-dry condition in the long term storage.