Study On Desiccation Tolerance Of Pugionium Cornutum

Pugionium cornutum, biennial plants in cruciferae of Pugionium Gaertn, were endemic species to China. As a nutrient-rich and green sandy vegetable, P. cornutum has higher development value. P. cornutum seeds during the development and maturation were used as material in this study, and respectively by artificial after flowering, natural and secondary dehydration. The change of germination rate, vigor and protection system of P. cornutum seeds with different moisture contents and dehydration process were measured, studied on the time to obtain the desiccation tolerance of P. cornutum seeds, the strength of desiccation tolerance and the mechanism for the formation of desiccation tolerance, which provide theoretical basis for storage of the seeds and germplasm preservation. The main results showed that:1. From20～60DAF, the moisture content of P. cornutum seeds decreased gradually, and the seeds could germinate and obtained desiccation tolerance at60DAF.2. P.cornutum seeds have the characteristics of dormancy, and storage can break the sees dormancy. Moderate dehydration can promote germination and benefit to storage of P.cornutum seeds.3. In the process of developing and no desiccation tolerance of P.cornutum seeds (In the60DAF before), the contents of MDA, soluble sugar and protein increased sharply with dehydration of P.cornutum seeds, but the activity of SOD decreased and the activity of CAT increased. In the process of formating desiccation tolerance of P. cornutum seeds, the protection system (the activity of SOD, CAT, POD, APX and LOX) enhanced and the contents of MDA, carbohydrate and protein increase.4. The germination rate and vigor of P.cornutum seeds moisture content of4%decreased after imbibition, but the germination rate and vigor of seeds increased after storage the sealed for3months, and the germination rate was more than80%. With secondary dehydration, the germination rate and vigor of seeds imbibed were decreased, and the vigor of seeds no-imbibed also were decreased; at the same time, mild dehydration can promote germination of seeds moisture content of4%, but excessive dehydration was reduced germination rate.5. Imbibition weaken the role of the P.cornutum seeds protection system, such as the activity of antioxidase (SOD, CAT, POD and APX) and LOX decresed, the content of MDA increase, and the contents of carbohydrate and protein decreased; but there was no obvious effect on desiccation tolerance of P.cornutum seeds to imbibition.