Study On Dormancy Characteristics And Germination Physiology Of Four Varieties Sabina Chinensis Seeds

Sabina chinensis(L.)Ant.is the evergreen tree plants under Pinales,Cupressaceae,Sabina Mill,which is native from China.It can reach 20 meters in height,live for hundreds of years,and has high ornamental value.Many regions of our country are distributed,and large diameter class even historic trees are not uncommon.However,Sabina chinensis seeds is difficult to germinate under natural conditions.This experiment studied on dormancy characteristics,content of storage material and endogenous hormones of different varieties of Sabina chinensis seeds to discuss the dormancy mechanism of Sabina chinensis seeds in order to provide theoretical basis for production and breeding research of Sabina chinensis seed sowing.The main conclusions are as follows:1.The germination of Sabina chinensis seed has by higher rate of empty kernel after the determination.And overall water absorption rate will decrease with aturated state,which can produce certain effect to seed germination.2.Sabina chinensis seeds could not germinate under conventional conditions,but germination appeared after low temperature stratification,indicating that low temperature stratification could break the physiological dormancy state of Sabina chinensis seeds.The effect of exogenous GA is relatively insignificant,and high concentration GA can inhibite the germination of cypress seeds.The seed coat was etch for 15min with H2SO4,and the germination effect was more obvious.,the results showed that the hard seed coat was also an important factor of Sabina chinensis seed dormancy.3.In the process of low temperature stratification,the content of soluble sugar first decreased,then increased and last decreased,while the content of soluble protein first increased and then decreased,the overall trend were downward.In the early stage of stratification,starch showed a downward trend;in the middle stage of stratification,showing storage material transformation obstacles appeared,and Juniperus scopulorum'Blue Heaven' was especially obvious.The contents of nutrients fluctuated in different Sabina chinensis.seeds decreased with the extension of the stratification time,which proved that seeds constantly consumed nutrients in the process of stratification to provide energy for the development and germination of seed embryos.4.The content of GA3,IAA and ZR appeared different changes of variation during low temperature stratification.They all increased with the extension of stratification time.The content of ABA eventually decreased,which indicated that the content of germination inhibiting substances was decreased in the course of seed stratification,while the content of substances promoting germination was increased.At the same time,GA3/ABA,IAA/ABA and ZR/ABA ratio all increased compared with the initial value,indicating different endogenous hormones coordinated with each other and continuously relieved dormancy,which was the key factor of seed germination.