The Influence Of Naphthalene And Pyrene On The Rice Physiological And Production Quality

Polycyclic aromatic hydrocarbons (PAHs) is a group of organic compounds, which is two or more benzene rings polymerized with different ways, and known as the earliest type of chemical carcinogens.Because its difficult degradable, strong durability and has strong "carcinogenicity-mutagenicity teratogenicity" effects in the environment, the impact of PAHs on the environment was concerned. Through the industrial wastewater irrigation, atmospheric pollution settlement, and uses pesticides, organic pollutants can inpour the field, and then influence the crops growth and development. In this Study, different genotypes of rice were choosed as the example. toxicity effects on high plant was tested, and PAHs data of plant toxicity was obtained. Studied two kinds of different PAHs: naphthalene (NAP,2 ring) and pyrene (PYR,4 ring) stress on four different types rices (conventional japonica:Nanjing 44 and Ningjing 3, conventional indica rice:Nanjing 16 and Yangdao 6).1. The influence of naphthalene and pyrene on the rice yield quality. NAP and PYR have the most significant influence on spikelets per pot and seed setting percentage of the component of yield. Compared with NAP, PYR has greater influence on the quality of the rice, it is the result of its significant inhibitory on the spikelet and number of tillers of rice. Both NAP and PYR can affect the rice quality, and the effect to the chalkiness degree of the rice is obvious, then is milled rice rate head rice rate, the amylose content and protein content, but they almost have no influence on brown rice rate.2. The influence of naphthalene and pyrene on the rice photosynthetic characteristics of rice at the panicle differentiation period. The photosynthetic and fluorescence parameters of rice at the panicle differentiation period such as:chlorophyll content, original light conversion efficiency (Fv/Fm), PSII potential activity (Fv/Fo), quantum yield of PSII (OPSII), net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) were influenced by the two organic pollutants. Moreover, on the above index, the influence of pyrene was obviously higher than naphthalene. In each of the chlorophyll fluorescence kinetics parameters, Fv/Fo is the most sensitive indicator to organic pollution stress. Therefore, chlorophyll fluorescence parameters Fv/Fo can be make the sensitive diagnostic Indicator of toxicity of rice.3. The influence of naphthalene and pyrene on the rice morphological character. naphthalene and pyrene have greatly influence on the plant height, leaf length, leaf width, number of tillers, shoot dry weight of 7 days after treatment, the jointing stage and heading stage of the rice was studied, the effects of jointing stage is most significant. The inhibition degree of pyrene was obvious higher than naphthalene on the above indexes, so pyrene has higher poisonous on plant. Low concentration of naphthalene can promote plant height, leaf length and leaf width of rice, which has greater promotion to conventional japonica Nanjing 44 and Ningjing 3 and has less effect to conventional indica Nanjing 16 and Yangdao 6. High levels of naphthalene and pyrene has obvious inhibition to the morphology growth on rice. Moreover, different varieties of rice have the different sensitivity to naphthalene and pyrene, conventional japonica rice was more sensitivity than the conventional indica rice.4. The influence of naphthalene and pyrene on the rice hardiness physiology. PYR and NAP treated on rice cause the leaf malondialdehyde (MDA) content of the rice increasing in the next 7 days,14 days and 21 days later, which indicated that NAP and PYR can cause the peroxidation stress in rice. Three kinds of the antioxidant enzymes--superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) has the tendency that first induction and then inhibit with the increase of the NAP and PYR treated level, and POD showed most strongly resistance to the organic pollutants, then was SOD, CAT the is most sensitive to organic pollutants. Therefore, CAT can be used as organic pollution sensitive indicator to the plant.