Recently, a clover-breeding program has been launched using the genetic diversity of wild clover species (Trifolium spp.) in order to release new clover germplasms in Iran. Seed dormancy was the major limitation for using these germplasms. To resolve this issue, 12 accessions of T. campestre Scherb., T. diffusum Ehrh., T. echinatum M. Bieb., T. hirtum All., and T. lappaceum L., wild species, together with cultivated species (T. resupinatum L.) which had been selected from previous studies were subjected in this research. Clover seeds were treated by two thermal (2 and 21 °C) and two scarification treatments, in a factorial design. F-test indicated a significant difference (p < 0.00) for germination rate between scarified and non-scarified treatments. However, the cold treatment did not increase the seed germination rate in the non-scarified groups, even though the seeds were transferred from 2 to 21 °C after 4 weeks of seeding. Whereas, the seed coat scarification had a high positive significant effect on seed germination rate. It means the seed dormancy was physical rather than physiological. Based on of Duncan’s test and cluster analysis, the accessions were grouped into three classes in accordance with variation in seed hardness: i-accessions of T. resupinatum which showed no seed coat hardness, ii- accessions of T. campestre with a slightly degree of seed hardness, and cluster iii- containing the accessions of four wild species with severe seed hardness. In addition, there was diversity in seed germination for different seed coat colors. Since brown seeds showed more water permeable coats, breeding for this color type leads to soft-coat seeds. Finally, it is proposed that the seed coat scarification is an essential process before sowing of wild clovers' seeds.

最近，利用野生三叶草物种（Trifolium spp。）的遗传多样性启动了三叶草育种计划，以便在伊朗释放新的三叶草种质。种子休眠是使用这些种质的主要限制。要解决此问题，12个国家加入T.坎佩斯特里Scherb，T. diffusum Ehrh，T. echinatum M. BIEB，T. hirtum全部。和T. lappaceum L.，野生种，栽培种在一起（ŧ upL.），从以前的研究中选择了本研究。三叶草种子经过两次热处理（2和21°C）和两次划痕处理，采用析因设计。F检验表明，疤痕疗法和非疤痕疗法之间的发芽率存在显着差异（p <0.00）。然而，即使种子在播种4周后从2°C转移到21°C，冷处理也不会增加非钙化组的种子发芽率。而种皮的疏松对种子的发芽率具有很高的积极显着影响。这意味着种子休眠是物理的而不是生理的。根据邓肯氏试验和聚类分析，根据种子硬度的变化，将种质分为三类：i-种质T. resupinatum这表明没有种皮硬度，II-种质T.坎佩斯特里具有轻微程度的种子的硬度，和群集III-含有的与严重种子硬度4个野生物种的种质。此外，不同种皮颜色的种子发芽也有差异。由于棕色种子显示出更多的水可渗透的皮毛，因此这种颜色类型的繁殖会导致软皮种子。最后，建议在播种野生三叶草种子之前，种皮的清除是必不可少的过程。