Antioxidations and Their Correlations with Total Flavones and Anthocyanin Contents in Different Black Rice Varieties

The antioxidations and their correlations with total flavones and anthocyanin contents in different black rice varieties were studied. The results indicated that the great differences in total antioxidant capacity （TAC）, scavenging free radical capacity （SFRC）, total flavones and anthocyanin contents existed among 242 black rice varieties. Comparisons of TAC, SFRC, total flavones and anthocyanin contents of different black rice types showed that the differences between black rice and white rice, indica one and japonica one, and nonglutinous one and glutinous one were significant at 0.01 levels, respectively. This showed that the TAC, SFRC, total flavones and anthocyanin contents of japonica type were higher than those of indica one, and nonglutinous type were higher than glutinous one. According to the fast clustering procedure, 242 black rice varieties could be clustered into 10 clusters, 184 indica rice varieties into 10 clusters, and 58 japonica rice varieties into 6 clusters. Most significant （P〈0.01） correlations existed between TAC and total flavones and anthocyanin contents, and between SFRC and total flavones and anthocyanin contents of black rice, respectively. This showed that the antioxidation of black rice was closely correlated with its active compositions of flavones and anthocyanin.

Measurement of Some Physiological and Biochemical Indexes of the Antisense Fragment of CYP86MF Gene Transgenic Male Sterile Plantlets in Chinese Cabbage-Pak-Choi

In order to study the mechanism of the transgenic male sterility induced by the antisense fragment of gene CYP86MF, some physiological and biochemical indexes were compared between the transgenic plantlets of Chinese cabbage-pak-choi(Brassica campestris L. ssp. chinensis Makino)and their controls. Results showed that there was significant difference between content of the endogenous hormones in leaves and floral buds. GA3 contents in leaves of the transgenic plantlets of B. campestris L. ssp. chinensis Makino cv. Shanghai-qing and cv. Youqing were reduced by 31. 72 and 46. 88% respectively as compared with those of their controls, and GA3 contents in floral buds of them were reduced by 62. 92 and 80. 57 % respectively. In addition, ZT contents in leaves of cv. Shanghai-qing and cv. Youqing were reduced by 11. 81 and 181. 20% respectively as compared with those of their controls and those in floral buds were reduced by 105. 94 and 128.75 % respectively. But, ABA content in transgenic plantlets was significantly higher than that in non-transgenic plantlets. However, differences among respiratory rate and cyanide-resistant respiratory rate, the photosynthesic rate and the content of total flavones in floral buds were not significant. In this study, the results indicated that the gene CYP86MF might be one of the key functional genes to control fertility of Chinese cabbage.

Effect of Light Intensity on Leaf Photosynthetic Characteristics and Accumulation of Flavonoids in Lithocarpus litseifolius (Hance) Chun. (Fagaceae)

The active compounds in herb drugs are mainly secondary metabolites, which are greatly influenced by external conditions. Particularly, light intensity has a great influence on the photosynthesis and accumulation of secondary metabolites. In this study, the light intensity was changed, and the influence of the light intensity on leaf photosynthetic characteristics, antioxidant enzyme activity and flavone contents of Lithocarpus litseifoliusp (Hance) Chun. was discussed. The results showed that (1) L. litseifolius is a typical heliophyte. As the light intensity decreased, the contents of chlorophyll a (Chl a), chlorophyll b (Chl b) and total chlorophyll (Chl a + b) all increased. However, the Chl a/b ratio gradually decreased. The daily variation of net photosynthetic rate changed from a double-peak curve under natural light to single-peak curve under 20% full light two shading nets. (2) As the light intensity decreased, the SOD and POD activities and the soluble proteins content decreased in the leaves. In contrast, the malondialdehyde content increased. (3) The flavone content was the highest in leaves at one shading nets 60% of full light, and the lowest occurred in leaves at two shading nets 20% of full light. A comprehensive analysis indicated that an appropriate shading could induce shade tolerance in the leaves of L. litseifolius, which promoted the accumulation of flavonoids. L. litseifolius should be planted in the lower position of sunny slope or the upper position of shady slope to increase the content of flavone in the leaves.