Effects of presowing treatments, desiccation and storage conditions on germination of Strychnos nux-vomica seeds, a valuable medicinal plant

Seeds of Strychnos nux-vomica have slow and erratic germination; thus different presowing treatments were applied to enhance the germination of its seeds collected from Tamaraikulam, Tamil Nadu, India. In addition, the effects of desiccation and different storage conditions on the germination of S. nux-vomica seeds were investigated. The results show that soaking in 500 ppm gibberellic acid (GA₃) for 24 h, incubation of seeds at 40 °C for 3 days and alternate water soaking (16 h) and drying (8 h) for 14 days significantly increased the percentage germination compared to the control. Desiccation of seeds down to 10% moisture content resulted in better germination. Germination of S. nux-vomica seeds differed significantly between different storage periods, moisture contents of the seed and for first and second order interactions (p<0.001). The highest germination (92%) was achieved when seeds with 10% moisture content were stored at ambient temperature for 30 weeks. Evidence from the present study indicates that S. nux-vomica seeds possess physiological dormancy that can be broken effectively by after-ripening. As seeds of S. nux-vomica are found to be desiccation tolerant, dry seed (10% moisture content) can be hermitically stored at ambient temperature for 30 weeks without losing their viability.     

薄皮甜瓜后熟过程中香气成分的动态分析

采用SPME与GC-MS联用技术,测定哈甜-2号薄皮甜瓜后熟过程中7个时期果实香气物质的种类及其相对含量。试验共检测到香气物质77种,香气物质的种类随果实的后熟而减少,且含量均有不同变化。其中酯类物质达40种,占香气成分峰面积的90 %以上,共有12种特征性酯类,包括乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸异丁酯、丁酸乙酯、乙酸丁酯、乙酸-2-甲基-1-丁酯、3-羟丙基硫代乙酸酯、乙酸己酯、2,3-丁二醇二乙酸酯、异丙氧基乙酸乙酯和乙酸苄基酯。酯类物质是果实香气的重要组成成分,其中乙酸乙酯与2,3-丁二醇二乙酸酯相对含量的变化较为明显。     

睡布袋播种育苗技术

由于我国与原产地的环境的差异,引进睡布袋种子发芽率极低。在南京地区,通过引进生长良好的雌雄二株睡布袋进行授粉。在成功收获种子的基础上,进行播种、育苗试验。通过不同小气候的环境营造,提供一套适合南京地区睡布袋生长的播种、育苗技术。     

Effects of after-ripening and storage regimens on seed-germination behavior of seven species of Physaria

The after-ripening response has been well documented in many plant species but studies of this topic are lacking in many new oilseed crops such as Physaria. In a factorial experiment, we tested the effect of different after-ripening periods and germination conditions on freshly harvested seeds of seven Physaria species, Physaria argyraea, Physaria fendleri, Physaria gracilis, Physaria rectipes, Physaria recurvata, Physaria sessilis, and Physaria thamnophila. The seeds were stored for 4 and 12 weeks over two saturated salt solutions (LiCl and MgCl₂) to equilibrate seed moisture at three storage temperatures (5, 25, and 35 °C). We likewise tested a dormancy-breaking protocol on these species by using conditions previously recommended for use in genebanks for P. fendleri. The germination tests were conducted with light (1052 lux) and gibberellic acid (GA₃) (100 ppm) and without them. Results suggested that conditions previously set for P. fendleri are also adequate for P. gracilis, P. recurvata, and P. sessilis, but may still be not optimal for the perennial species, P. argyraea, P. thamnophila, and P. rectipes. Overall, higher germination percentages were obtained with light and GA₃ treatments. In all species, we observed slight differences between total germination results after 4 weeks and 12 weeks of storage, with higher values evident only in P. fendleri, P. recurvata, and P. thamnophila after their fresh seeds were subjected to 12 weeks of after-ripening at warm temperatures.