Effects of different pre-sowing seed treatments on germination of 10 Calligonum species

A greenhouse experiment was conducted to study the effects of abrasion, sulphuric acid, boiling water, cold stratification and seed exudate treatments on the germination of 10 Calligonum species. That are dominant shrubs used for restoration of desert vegetation in mobile sand dunes and stabilized sand fields in the northern desert of China. Little is known about their germination characteristics. In August–September 1998, seeds of Calligonum were collected and were treated by five pre-sowing treatments before the germination experiments. The results show that the germination response of seeds to the different pretreatments was more or less similar for all 10 Calligonum species. The germination percent of seed from the 10 species was lowest for exudate treatments and highest for abrasion treatments. The abrasion, sulphuric acid and cold stratification treatments significantly promoted overall germination. Compared with the control, the exudate treatment significantly hampered germination, rate of germination and bolstered dormancy for almost all species. The cold stratification treatment can break the dormancy of viable Calligonum seeds and increase the germination, but it has lethal effect on viable seeds probably as well as the boiling water treatments. Almost all germination parameters showed significant difference between the pre-sowing treatments for all 10 Calligonum species. The speed and percent germination of the Calligonum species can be greatly increased by mechanical scarification or acid treatments. The results show that seeds of C. junceum have good germination potential. These conclusions are very important because Calligonum species can be propagated by seed in the arid desert regions.