Effects Of Dust Cover On Impatiens Hawkeri About Photosynthetic Characteristics And Nitrogen Distribution

Atmospheric dust pollution has been the important environmental problem faced by many countries and regions, the dust of humans and other animals and plants are the adverse impact. Commonly used in this study, chengdu garden herb flowers Impatiens hawkerins as research materials, starch solution spraying plant leaf surface was used to simulate natural dust sedimentation, discusses different concentration dust cover on Impatiens hawkerins leaf photosynthetic characteristics and the influence of photosynthetic nitrogen distribution characteristics. The concentration gradient of the starch solution set to:?T1? 0.1 mg. ml^-1, ?T2? 0.2 mg. ml^-1, ?T3? 0.4 mg.ml^-1, ?T4? 0.6 mg. ml^-1, to do not spray starch plant as a blank control ?CK? aqueous solution. Starch solution to deal with different concentrations were determined respectively after 90 d of Impatiens hawkerins light response curves of the blade, CO2 response curve, the chlorophyll content, specific leaf area, leaf nitrogen content and leaf nitrogen distribution proportion in photosynthetic mechanism. Study the main results are as follows:?1? With the increase of dust concentration, Impatiens hawkerins leaf chlorophyll a, b and total chlorophyll presents first the change trend of lowered later; Plants than leaf area with the increase of dust concentration to reduce after rising trend; With the increase of dust concentration, the maximum net photosynthetic rate of plant leaf, maximum carboxylation rate, and maximum electron transfer rate consistent declining trends; Plants of the dark respiration rate with the increase of dust concentration was reduced after the first rise trend.?2? The distribution of nitrogen in the plant leaves can response plants in city by the external environment stress survival strategy. The total leaf nitrogen content with the increase of dust concentration showed a trend of gradual decline, but no significant differences between treatment; With the increase of dust concentration, leaf nitrogen in the allocation of photosynthetic mechanism after the first high low trend PT, the maximum value appeared in T2 (0.2 mg. ml^-1), in the low concentration of dust cover blade, leaf nitrogen content was increased, high concentration of dust cover blade, leaf nitrogen content gradually reduce; Nitrogen in leaf carboxylation and catch the light system allocation proportion of PC and PL also showed a trend of first after the high low, and can learn components in biological force allocation proportion of PB with the increase of dust concentration decreases gradually. Plant cover on the surface of blade, stomata on leaf form shading, obstruction, affect plant to absorb light energy as well as to the raw material for photosynthesis carbon dioxide absorption, lower leaf nitrogen distribution proportion in biological force can learn component; A high concentration of dust cover blade, will reduce the leaf chlorophyll content, lower leaf nitrogen in the allocation of photosynthetic mechanism as a whole, reduce nitrogen in leaf carboxylation allocation proportion in the system, light system. Thus reduce the photosynthetic rate of plant individual, affect the normal growth and development of the plant.?3? With the increase of covering the dust concentration on the surface of the leaf, Impatiens hawkerinsmaximum net photosynthetic rate (P_max) and electron transfer rate (J_max) there is significant positive correlation between; Maximum carboxylation rate (V_cmax) and the _maximum electron transfer rate (J_max) there is significant positive correlation between; Assigned to the nitrogen on the biological energy ?P_b? and _maximum net photosynthetic rate (P_max), the largest electron transfer rate (J_max), _maximum carboxylation rate were very significant positive correlation (V_cmax). Dark respiration rate and distribution on the biological energy nitrogen ?P_B?, assigned to carboxy into use nitrogen ?P_c?, assigned to the photosynthetic mechanism of nitrogen ?P_T? were extremely significant positive correlation.