บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Membrane stabilization and desiccation tolerance during seed corn (Zea mays L.) drying.

Chen, Y. G.;

Dissertation Abstracts International. B, Sciences and Engineering Year: 1990 Vol: 51 Issue: 8 Pages: 3620B

1990

บทคัดย่อ

Membrane stabilization and desiccation tolerance during seed corn (Zea mays L.) drying.

A preconditioning process (treatment at 35 deg C prior to high-temp. drying) that precludes high-temp. (>45 deg ) drying injury without major moisture loss was used to study the nature of desiccation damage in high-moisture maize seeds. Seed germination was negatively correlated with leachate conductivity and sugar leakage after different times of preconditioning, indicating the involvement of membrane function in the damage. The percentage composition of sucrose and raffinose increased significantly during preconditioning. High correlations between the ratio of raffinose: sucrose and warm germination, conductivity and sugar leakage indicated the added effect of raffinose on the induced protection. It was suggested that soluble sugar compositional relationship rather than absolute content may play an important role in protecting maturing seed from high-temp. drying damage. Among membrane lipids, phosphatidylcholine (PC) accumulated, resulting in an increase in the PC:phosphatidylethanolamine (PE

) ratio from 3.6 to 8 within 48 h of preconditioning. The increase in PC:PE ratio coincided with decrease in both phase transition temp. and enthalpy of transition, which indicate more stable membranes. An increase in fatty acid saturation may result in membranes which more easily cope with high-temp. desiccation. The ABA levels and appearance of desiccation-induced protein indicated that preconditioning and the newly induced protein may be related to the transition from desiccation intolerance to desiccation tolerance during postharvest drying.