Studies On Ftir Features And Physiological Characteristics Of Broad Bean Under Aluminum

Aluminum (Al) toxicity is the major factor limiting crop productivity on acid soils, which comprise up to 40% of the world's and 21% of Chinese arable lans. Broad bean(Vicia faba Linn) is a important edible bean and also can be used as medicine. It has a high economic value and the strong ability of nitrogen fixation. This study had researched on the spectra characteristics of two cultivars broad beans, Yundou83324(high aluminum tolerance) and Yundou8363(low aluminum tolerance), treated with different concentrations of aluminum and different times under the 50μmol Al by using fourier transform infrared spectroscopy (FTIR).The contents of soluble sugar(SB), total protein(TP), and malondialdehyde(MDA) in broad beans were also detected by using method of anthrone colorimetry, coomassie brilliant blue and thiobarbituric acid colorimetry, respectively. The aim of this study is to clarify the spectra characteristics, the variations of SB, TP and MDA of broad beans under Al stress and the correlations between the spectra characteristics and physiological indexes and to confer the probability of broad bean Al endurence by FTIR. Main results were as follows:1 Under aluminum stress in different concentrations and different times in the 50μmol Al,the variation of FTIR bands of two varities broad beans occured on ordinate only. There was no new FTIR band appeared on abscissa. All of these suggested that aluminum stress could not change the basic chemical composition of the broad beans except for the concentration of the compositions.2 Under aluminium stress in different concentrations, FTIR results showed that there were a higher threshold of aluminum tolerant concentration in root, stem and leaf of broad bean 83324 compared with broad bean 8363 and physiological results showed that lower concentration of aluminum could cause the decreasement of soluble sugar and total protein and the increasement of malondialdehyde in root, stem and leaf of broad bean 8363 compared with broad bean 83324.3 Under 50 umol Al stress in different times, FTIR results showed that broad bean 83324's leaf had a longer threshold of aluminum tolerant time than that of broad bean 8363.Although root and stem's thresholds time were similar, broad bean 8363's root and stem were more inhibit than broad bean 83324 after threshold time. Physiological results showed that under 50 mol Al stress in different times, the decreasement of soluble sugar and increasement of malondialdehyde could be induced in the shorter time in the root, stem and leaf of broad bean 8363 compared to broad bean 83324. Although the times induced the decreasement of total protein in the two cultivars broad beans were similar, the contents of total protein in broad bean 8363 was affected more obviously.4 The correlation coefficients between soluble sugar and band at 1060 cm-1, protein and band at 1645 cm-1 were more than 0.8, it indicated that they had significant positive correlation, respectively. The correlation coefficients between malondialdehyde and band at 2928 cm-1 indicatd there were negative correlation between them.Data from both FTIR and physiological characteristics identified that broad bean 83324 had a stronger aluminum tolerance than broad bean 8363.The aluminum tolerant difference of broad bean was detected by FTIR with features of simple, nontoxic, quick and accurate.This was scientific and reliable method used for mesuring broad bean aluminum tolerance by comparing the relationship between band at 1060 cm-1 and soluble sugar, band at 1645 cm-1 and total protein, band at 2928 cm-1 and malondialdehyde,respectively. At the same time, this study also provided a new reference material and research method on aluminum tolerant mechanism of broad bean.