engleski

Effect of germination media pH on α -amylase activity and early seedling growth of red clover

Germination of seeds is a complex physiological process triggered by imbibition of water. During the seed germination enzymes become active and seed increases its metabolic activities. α -amylase plays an important role in hydrolyzing the endosperm starch into metabolizable sugars, which provide energy for seedling growth. Understanding the effect of different germination media pH on α -amylase activity and early seedling growth might help to decrease time necessary to identify acid- soil tolerant legume genotypes. The objective of this study was to examine the effects of germination media pH on α -amylase activity, seed germination and radicle length of red clover during its first nine days of germination and to determine the relationship among factors associated with early red clover growth. Seed was germinated in growth chambers at the constant temperature of 7oC and four pH levels of germination media (4, 5, 6 and 7). α -amylase activity was tested in dry seed extract and in seed samples under germination. Samples were taken during the 1-9th day of germination period. Activity was determined by the colorimetric method using soluble starch as a substrate and 3, 5 - dinitrosalicylic acid as a reagent with hydrolytic products. Germination and radicle length was recorded on 9th germination day. Results indicated that pH of germination media affected α -amylase activity, seed germination and radicle length (p=0.01). Activity at the same pH value was more intensive in dry seed extract and during the first two days of germination than after second day of germination, when activity rapidly decreased. However, the overall activity of α - amylase was higher at 5 and 6 of pH than at pH 4 and 7. The highest seed germination was found at pH 5. Similar to activity of α -amylase, length of radicle was higher at pH 5 and 6 than on 4 and 7. α -amylase activity was correlated to seed germination and radicle length (p=0.05).

red clover ; pH ; α -amylase activity ; germination

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