石灰花楸种子休眠机理及解除方法

Dormancy Mechanism and Breaking Techniques of Sorbus folgneri Seeds

对石灰花楸种子休眠解剖结构基础、休眠影响因素和解除方法的实验研究结果表明：石灰花楸种子由种皮和胚两部分组成，胚形态发育完全，种皮木质化程度较高、透气性障碍显著，在种皮和胚中均存在萌发抑制物质，休眠类型为综合性休眠（PY＋PD）。低温层积40—45d，石灰花楸种子萌发率可达85％以上，是解除休眠的有效途径。种子去除不同部位种皮、种胚、种胚去除不同量子叶处理，萌发率为18．33％-51．67％，种子萌发后幼苗多不能正常生长；种子经各种浓度和时间梯度的NaOH、H2SO4和GA，处理，仅75％H2SO4处理5min可以打破休眠，种子萌发率为25．67％。

Dissection structure, dormancy influencing factors and breaking techniques were investigated of Sorbus folgneri. Seed. Seed of Sorbus folgneri is composed of lignified seed coat and morphologically well developed embryo ,seed coat with an obvious air permeability obstruction, and substance extracted from seed coat and embryo inhibited the germination of cabbage seeds. These results showed that Sorbus combinational dormancy mainly caused by seed coat obstruction and germination inhibited substance. Seeds of Sorbus folgneri germinated more than 85% by cold stratification for a period of 40 -45 days,which was effective method to break dormancy. Seeds with parts of seed coat removed, isolated embryos and embryos with parts of cotyledons removed germinated from 18.33% to 51.67% ,but had undesirable effects with abnormal seed- lings. Among various concentrations for different duration of NaOH, H2SO4 and GA3, only seeds treated with 75% H2SO4 for 5 min broke dormancy and induced only 25.67% germination.