Differences Of Physiological Characteristics, Yield And Quality, Regulation Of Pigment Deposition In Skins Of Colored Peanut

The experiment was carried out in agronomy experimental station of Shandong Agricultural University from 2013 to 2014. Taking white peanut cultivar Jinhua1012, purple peanut cultivar L hei, black peanut cultivar H hei and ordinary pink peanut cultivar 606 as experimental materials to study the differences of physiological characteristics during growth, yield and quality, pattern of color formation, regulation of pigment deposition and super-molecular structure changes in different skins during development of colored peanut. The main findings were as follows:1 Difference of physiological characteristics in levels of colored peanut The photosynthetic rate(Pn), the actual photo-chemical efficiency(ФPSⅡ) and maximum photo-chemical efficiency(Fv/Fm) all showed a unimodal curve after flowering. Net photosynthetic rate of the colored peanut was significantly lower than that of ordinary pink peanuts in the entire growth stages, The net photosynthetic rate of white peanut leaves was the lowest. Chlorophyll content have a significantly decrease in pegging into the soil. Chlorophyll about LH and HH were significantly lower than JH and CK before pegging into the soil 40 d. Chlorophyll of JH content decreased gradually and the other three cultivators fell more obvious. Colored peanut during pod development in soluble sugar content was significantly higher than that of ordinary pink peanuts. On field cultivation, diseases and insect pests of colored peanut was more serious than ordinary pink peanuts. CAT was lower in purple peanuts and black peanuts than the general content of leaves pink peanut and white peanuts. And purple peanuts and black peanuts had a higher cumulative MDA content. And lipid per oxidation and greater free radical damage to cells caused by reactive oxygen species, the antioxidant capacity of the plant was poor and the degree of metabolic activity inside the blade was low, higher degree of aging.2 Differences of yield and quality of colored peanut Under the same cultivation conditions, ordinary pink peanut pod yield was significantly higher than the colored peanut. It could increase about 10%, mainly due to the common pink peanut plants larger number of fruit per plant, followed by purple peanuts. In addition, black peanut and ordinary pink kernel rate was significantly higher than the white peanuts and purple peanuts. The kernel rate of white peanut was low. So white peanut skin was thin, and the thickness of purple peanuts and black peanut.Fat acids in white peanuts and common pink peanut were significantly higher than the purple peanuts and black peanuts. Protein content in colored peanuts was significantly higher than the ordinary pink peanut. Soluble sugar content was no significantly difference. The content of amino acid in colored peanut was significantly greater than ordinary pink peanuts and its nutritional value is superior to ordinary pink peanuts. Palmitic acid content in black peanut was significantly lower than other three cultivators, but higher levels of stearic acid content of purple peanuts. And the black peanuts significantly higher than white peanut and ordinary pink peanuts general. Fatty acids showed no significant difference. Seed kernel O / L values were 0.99, 1.37, 2.28 and 1.28.3 Difference of regulation of pigment deposition in colored peanut skins Pigment substance of peanut skin is mainly distributed in 1-2 layers of epidermal cells. There are some differences in skins about pigment of substance deposition time and location. With the development of the skin, the phenomenon of color mutations pegging into the soil 15-25 d in purple peanuts and black peanuts, the color of skin from white to purple mutation. During the whole skin development, white peanut has no significant change in the color,but the color of general pink peanut gradually deepened. Due to pigments and flavonoids, white peanut seed coat presented white with yellow. The ordinary pink peanut contained more flavonoids and less pigment, the color of skin gradually showing pink and yellowish. The purple peanut and black are mainly affected by color substance from white to purple and then turns purple. The black peanuts and purple peanut seed coat color presented purple with black simultaneously, but the structure of cells and deposition time and location of substance pigment in skin showed significant differences. With the development of the skin, the black peanut skin pigment inside the cell gradually accumulate and evenly distributed within the seed coat cells, showing a homogeneous state, cells arranged in neat rows, no change in the shape. While the purple peanut skin cell shape change. The cells appeared to be transversely stretched and the pigment gathered around the cell wall, showing the state of aggregation.