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Screening on Adapatation to Light Intensity, Drought and Nitrogen and Their Phoysiological Difference in Different Rice Plants

Author: SunZhiWei
Tutor: LiXia；CaiQingSheng
School: Nanjing Agricultural College
Course: Botany
Keywords: high/low light drought stress nitrogen adaptability rice
CLC: S511
Type: Master's thesis
Year: 2009
Downloads: 19
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Abstract

With the twice green revolution of rice breeding which is the most important crop of the world, the production of rice has been improved notability by the enhancement of group utility rate of luminous energy and photosynthetic efficiency. But there are still many problems in rice breeding, such as:lack of resistance, weakness of adaptability, etc. It’s a restriction for the extending of improved variety of rice seed. In one hand, there are lots of reports about researches of the tolerance and adaptability to different environment and some of the reports have been used in rice breeding, but the researches aren’t useful in wild condition because they were taken in vitro. In another hand, there are less of the researches about tolerance and adaptability to total environment and the index about these researches. We found that the content of chlorophyll, leaf color(SPAD) and the ratio of root/shoot had a good prescription to tolerance and adaptability to total environment of rice by the selection of different of rice materials under different light, water and nitrogen condition in this research. The main results as follow:1. The index of selection of high and low light:there was a significant positive correlation with the degrees of photoinhibition between the decreases content of chlorophyll, Fv/Fm and the degrees of photoinhibition, the correlation coefficient of the decreases content of chlorophyll and the degrees of photoinhibition is-0.609(=0.000), the correlation coefficient of the decreases Fv/Fm and the degrees of photoinhibition is-0.282; there was a correlation(-0.329) between either the content of chlorophyll in the field condition or the changes of them and the decrease of dry weight after shading treatment, so the content of chlorophyll can be used as a parameter of shading and high light sensitivity.2. The selection of drought stress:the germination rate of rice has evident differentiation when treated with drought stress. In comparison with the germination rate of dry rice, we can make certain that the rice which germination rate exceeded 50% and grow well in both drought and wet conditions were high-anti-drought rice. By relativity analysis, R/S ratio in germination period was also a good screening index that has some relativity with germination rate. By clustering analysis, we could classify the different rice into six degrees on anti-drought ability.3. The selection under different nitrogen concentration:by different nitrogen concentration (57.2mg/L、114.3mg/L、228.6mg/L, NH4NO3) and N-free treated to hybrid rice materials, R/S ratio, dry weight were measured at the end of different nitrogen concentration treatment, after correlation and cluster analysis, the rice materials were clustered to 6 series according the different adaptability to nitrogen, then 5 of each series were chosen treated with N-free(no N in the solution) in order to illustrate the different response to N starvation of rice which is grown under different N concentration. SPAD, NRA, the content of Rubisco and protein were measured before and after N-free treatment. The results showed NRA, the content of Rubisco and protein showed that different environment N concentration can change the response of rice to N-free treatment:lower N concentration can enhance the adaptability of rice to N starvation and there were a significant correlation ship between SPAD either the content of Rubisco or protein.In conclusion, rice is influenced by environment at different way, but there are something similar in response in its growth and physiological change. In this research, we did not find a metarial, but all the content of chlorophyll, SPAD, Fv/Fm and the content of Rubisco can be used as index to the response of rice to high/low light, dry stress and nitrogen stress in rice wild condition breeding.

Screening on Adapatation to Light Intensity, Drought and Nitrogen and Their Phoysiological Difference in Different Rice Plants

Abstract

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