Dissertation > Excellent graduate degree dissertation topics show

Study on the Formation of Flower Color from Hibiscus Mutabilis

Author: ZhengZhi
Tutor: LvChangPing
School: Hunan Agricultural University
Course: Ornamental horticulture
Keywords: Hibiscus mutabilis Flower color Flavonoids carotenoids Anthocyanins
CLC: S685.99
Type: Master's thesis
Year: 2009
Downloads: 28
Quote: 0
Read: Download Dissertation

Abstract

Hibiscus mutabilis belongs to Malvaceae,deciduous shrub or subtree.lt has a long history of cultivation in home and a broad. The research was based on the various flower color of Hibiscus mutabilis from Hu Nan. The methods of different color measurement （checked using normal eye and spectrophotometer）,observation by visible spectra,specific color reactions and chromatography were used in this dissertation. The most studies focused on the three aspects:the first was the measurement and analysis of flower color; the second the effect of Physical and chemical factors on flower coloration:the third was the phytochemistry of flower pigments of Hibiscus mutilis petal. These data is useful for planting and breeding of the Hibiscus mutabilis.The results are indicated as follows:1.The flower color of 3 Hibiscus mutabilis cultivars was checked using normal eye and spectrophotometer.Lightness（L^*） and chromatic component （a^* and b^*）of these cultivars are obtained by spectrophotometer.According to the CIELAB color coordin-ate,all cultivars were divided into three groups:red, white,and pink based on the Q cluster analysis.In the same time,the system of flower color measurement of Hibiscus mutabilis was discussed.The digitization of flower color is very important for the studies of flower color of ornamental plants. Analysis of the CIELAB color coordinate of flower color,the relationship of significant negative correlations between a* and L^*was founded.That is,from green to red of flower color,the less lightness the flower has. But the significant positive correlation between b^* and L^* was showed in white, pink groups and red groups respectively.Those results show that a^* and b^* are the important factor for lightness and flower coloration.2.The color expression of flavonoids in white cultivars is not sensitive to temperature, light,and pH value.The color expression of anthoeyanins of red and pink cultivars is stable under 55℃in methanol and sensitive to light and pH value. Anthoeyanins degradate significantly in light.The red color of anthoeyanins in some cultivars fades gradually and has a bathoehromiec shift ofλ_vis-max:as The increase of pH value in solution.some metal ions, such as Fe³⁺,Mg²⁺,Al³⁺,Ca²⁺are positive to red cultivar’mu dan hong’ .Metal ions do not affect flavonoids in cultivar’zui fu rong’,obviously. These results emphasize that anthocyanins play significant roles in red and pink cultivars of the Hibiscus mutabilis.3. The flower pigment sarevery important for flower coloration.The study by UV-visible spectra indicate that flower pigments of Hibiscus mutabilis are consist of carotenoids,anthocyanins and other flavon oids.The characteristic absorption peak of carotenoid was 440nm and 470nm,the anthoeyanin was 531nm,and the other Flavonoid was 331nm and 271nm. There is only flavone in white color flower;the red and pink flower contains anthoe-yanlns and other flavonoids.4.To understand the quantitative effect of major pigment s on flower color variation in Hibiscus mutabilis cultivars,flavornols （FL）,carotenoids （CA）, chlorophylls（CH） and anthoeyanins（AN） were extracted from the flowers and analyzed both qualitative-ly and quantitatively with UV-visible spectral.The results indicated that all of the cultivars contain flavonol,which are colorless and act as the copigment for some color groups.The anthoeyanins were responsible for flower colors of the red,and pink, its content is important for the flower coloration.The relationship of significant negative correlations between total anthoeyanins（TA）,total carotenoid （TC）, total flavonoids （TF） and L^* was founded.The significant positive correlations between TA and a^*,TC and b^*were founded respectively.The content of TC is negatively related to TF and TA,but the content of TF is positively related to TA.At last,according to the content of flower pigments,all cultivars were classified into five groups:FLgroup,containing flavonols;FL,AN group,anthocyanins and flavonols;FL,CA group flavonols and carotenoids;FL,AN,CA group, anthocyanins, flavonols and carotenoids; FL, CH, CA, group,flavonols,chlorophylls and carotenoids.The classification according to flower color and pigments is correlative and this will be benefited for cultivar classification of Hibiscus mutabilis.

Related Dissertations

CLC: > Agricultural Sciences > Gardening > Ornamental Horticulture ( flowers and ornamental trees) > Flower trees in class > Other
© 2012 www.DissertationTopic.Net Mobile