| In this research we had studied effects of different light quality onpimiento in quality, developmental characteristic and photosynthesischaracteristic of seedlings. The result shows:1. White light and yellow light were better for cultivating healthyseedling, blue light, red light and green light were in turn. Ziguiren andHongyingda under green light was respectively 26.2% and 28.6% taller thanthat under white light, while that under blue light was respectively 14.7% and14.3%shorter than that under white light. Therfore, green light and red lightpromotes shoot elongation, while blue light dwarfs it. The stem diameter waslarger under white light and yellow light, smaller under green light and redlight. In addition, the dry weight was largest under white quality, secondlyyellow light and red light, smallest green light and blue light. As a whole, thehealthy seedling index indicates that the seedlings under white light andyellow light was most healthy, then blue light and red light, and green lightworst.The content of dissociative amino acid was largest under blue light andwhite light, then green light and yellow light, and red light lowest. Amongthree varieties, The content of dissociative amino acid of Hongyingda waslargest, then Huangoubao, and Ziguiren lest. Higher content of dissociativeamino acid build the base of protein synthsis. Similar to amino acid, thecontent of dissociative protein under white light, yellow light and red light less,and however green light lowest. It suggest that total enzyme activity was lowunder green light which is inefficient to plant growth. Among the threevarieties, Hongyingda was highest in the content of dissociative protein,Huangoubao less, and Ziguiren lowest. The root activity of all the three varieties was highest under yellow lightand white light, then blue light, then red light, and lowest under green light. Itsuggested that green light was not favorable for root development, sequentiallyaffects assimilation of nutrient. 2. Chl.a content and Chl.a/ Chl.b value in different pimiento varietieswere different obviously under the same light quality, and chl.a content andChl.a/ Chl.b value were highest under blue light, higher under white lightand yellow light, least under green light. The light qualities had obviouslyeffects on the fluorescence parameters in different pimiento varieties Values ofFv/Fm, Fv/Fo,φPS,qp were highest and NPQ was least under white lightamong different light qualities, which indicated white light was the most valid,yellow light, blue light, red light and green light in turn. The results showed white light and yellow light were good for cultivatingstrong seedling, blue light, red light and green light in turn. During the growthof the seedling, the leaves'activity of the POD,CAT,NR,APX was higherunder white light than other light qualities, but the activity of SOD was lowerthan others. The activity of SOD was higher under green light. Difference wasobvious among the different light qualities. White light was best. 3. Light quality has great effect on fluorescence parameter of differentpimiento variety. Fv/Fm, Fv/Fo, φPSⅡand qp are highest and NPQ is lowestunder white light, and yellow light, blue light, red light and green light lessefficient. It indicates that white lights is most efficient. Latent quantaefficiency and factual quanta efficiency under white light are highest, namelylatent energy catching efficiency of open PSⅡreaction center (quantaefficiency in electron transmitting) is highest. The highest qp suggested highestproportion of open reaction center in PSⅡreaction center. High proportion ofQA in oxidation form also suggest high quanta efficiency in electrontransmitting and high photosynthesis capacity. the lowest NPQ, namely lowestheat dissipation, indicate the highest photoenergy efficiency under white light. 4. Under lights quality, activity of POD, CAT, NR and APX was highestunder white light, and SOD activity was lowest under this condition. Hower,SOD activity was highest under green light.It was 4 times of control,whichindicates green light as a adversity for seedling and was not good forseedling's growth. SOD activity was not obvious difference under blue and redlight,it was lower under yellow light and lowest under white light. It is to saythe control is favorable for seedling growth. There is no obvious differencein SOD activity among different varieties under the same light. NR activity under green light was the lowest, only 25% of control, anda little higher under yellow light. It shows that seedlings as control has thehighest efficiency of nitrate utilization, and thus the nitric acid radical remnantof itself was little. Under green light the activity of this enzyme was the lowest,61.4% lower than control. Under light of the same quality, Huangoubao hashigher POD activity, while Ziguiren has the lowest POD activity under light ofany quality. CAT activity is the highest under the control,less higher underblue light, CAT activity of Hongyingda was highest among the three varieties.APX activity was higher under yellow and white light while green light ,bluelight and red light has not obvious effect on APX activity. There was obviousdifference among different light quality, white light was better. 5. Green light promotes the amplifation of stoma, and howeveraccelerates closing of stoma. Blue light can promotes stoma opening as redlight but more strongly than red light. Gs and size of stoma under white lightare the largest, so as photosynthetic rate, which was efficient for seedlinghealth. 6. There was obvious difference in photosynthetic rate under varioustreatments. Photosynthetic rate was higher under white light than any othertreatments. When the seedlings was transferred under natural light fromvarious light quality treat, values of the photosynthetic rates had same trend as... |
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