Studies On Physiological And Biochemical Changes Of Artificially Aged Pepper Seed And Renewing Its Vigor

Nowadays, there are lots of research reports about seed aging and deterioration mechanism at home and abroad, however the reports on capsicum seed's are seldom. In order to find out the reasons causing capsicum seed's vigor descent and its physiological and biochemical transformation laws and search for the effective approaches to increase the vigor and postpone the deterioration of the crop's seed, the author carried out the study to provide basis and reference for improvement of the seed vigor with manual acceleration of seed aging. And the effects of several treatments to renew the aged seed's vigor are compared. The results are as follows.1. With prolonging of the aging, germinating energy, germinating capacity and vigor index of the seeds tested had a dropping tendency and there were obvious difference in these three indexes during different aging days, except germinating capacity in the second day from aging, which indicates the vigor of the manual aged seed declines quickly than its life-force. The longer the aging lasts, the more seriously the seed deterioration is.2. Relative conductivity and MDA content of the seed's infiltrating solution both rose with the more serious degree of the seed aging, which shows the aging has a high effect on the cell membranous system. And conductivity and MDA content change will illustrate, to a certain extent, the strength of the membrane lipid peroxidation and the integration degree of the cell membranous system.3. In the process of aging, change of seed's dehydrogenates activity was not obvious, which replicates that the aging has little effect on the activity of the capsicum seeds.4.POD activity and SOD activity of the seed tested had obvious difference themselves, and the two indexes significantly reduced with the aggravated aging. Accordingly, descent of these two indexes may be another important reason causing the vigour descent of capsicum seed.5.Contents of the storage materials, such as soluble sugar, soluble proteins all descended gradually with the aggravated aging, which may be one of the reasons of the capsicum seed vigor descent.6. Results of the principal component analysis of the six indexes, including the relative conductivity, show that these indexes may be classified into two categories. The first category includes POD, SOD, soluble sugar and soluble protein which are not only the main factors of the vigour change but also the reliable indexes to examine the seed vigour. Another category has relative conductivity and MDA content.7. Five seed treatments all can make obvious increase of the aged capsicum seed's vigor, including wetting and drying cycle, PEG permeability control, seed soaking with CaCl2, AsA and GA. Among them PEG processing and GA processing have the better effect.