Dormancy Mechanism and Breaking Techniques of Sorbus folgneri Seeds

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 folgneri seeds exhibit 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 seedlings.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.