Determination the Vigor of Rice Seed with Different Degrees of Aging with Ultraweak Chemiluminescence During Early Imbibition

摘要

Ultraweak chemiluminescence (UCL) is the spontaneous light emission radiated from various biological systems derived from chemiexcitation of biological molecules during oxidative metabolic processes (Popp et al, 1988). Therefore, this weak light is a possible representation of physiological or pathological conditions of cells and tissues. Detection of UCL makes it possible to acquire immediate information on biological activities non-invasively (Popp et al, 1988). The most important aspect of the chemiluminescence (CL) in biological systems is that it gives readily detectable, continuously monitorable, non-invasive signals of oxidative metabolism. In recent years, a lot of evidence has been accumulated that interactions between water and food significantly affect the processing, storage and the quality of cereal products (Slawinska and Slawinski, 1997; 1998). Nowadays, CL-based methods have been developed for monitoring the investigation of reactions of water with cereal products (Popp et al, 1988) . The study of UCL of plant and its applications in agriculture has had very significant achievements. The UCL intensity changes with time, and the increasing rate of UCL reflects the germination ability of the seed. The emission pattern of chemiluminecence of the seed may suggest its metabolic status (Bajpai et al, 1991). With the present methods used for measuring seeds vigor, such as germination test and isozymes analysis, there are many disadvantages: (1) the time for measuring is too long; (2) the structure of the seed often should be destroyed; (3) lots of seeds are needed. The present investigation was done under accelerated aging (AA) condition. In fact, AA test, as imposed by high temperature and high relative humidity, provides a powerful way for the study of seed deterioration over a very short period. AA technique has been widely used in the studies of seed storability and deterioration (Heydecker, 1972). In the present study, the vigor of rice seeds was examined by measuring the differential characters of the seed UCL intensity during early imbibition (20-30 min). The intensity of UCL was observed to be related to the degree of aging of rice seeds during early imbibition. Rice seeds with shorter AA time had higher intensity of UCL during early imbibition (20-30 min). The germination rate of rice seeds showed an obvious positive correlation with the intensity of UCL. Our experiments suggested that aging degree of rice seeds could be judged from their UCL intensity during early imbibition, which might be a potential way in elaborating a fast, holistic and non-invasive method for the rapid evaluation of the aging degree of rice seed.