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A possible explanation for the electron/positron excess of ATIC/PAMELA

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Research in Astronomy and Astrophysics 2010年第1期10卷 39-46页

作者： Rui-Zhi yang Jin chang jian Wu Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

Results from PAMELA and ATIC indicate that the Kaluza-Klein type dark matter particles could be the annihilation source of the observed excess of electrons and positrons. Assuming the existence of a nearby black hole with 10000-100000 solar masses and a point source boost algorithm, we apply the standard propagation model and find that the results fit the data well.

关键词： dark matter - black hole physics - cosmic rays

Physiological mechanism underlying spikelet degeneration in rice

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Journal of Integrative Agriculture 2018年第7期17卷 1475-1481页

作者： WANG Zhi-qin ZHANG Wei-yang yang jian-chang Key Laboratory of Crop Genetics and Physiology of jiangsu Province/Innovation Center for Modern Production Technology of Grain Crops of jiangsu Province Yangzhou University

The phenomenon of degenerated spikelets is very common in cereals, and considered as a serious physiological defect and a main constraint to grain production. Understanding the physiological mechanism in which spikelet degeneration occurs would have great significance in enhancing yield potential in grain crops. Taking rice as an example, the paper reviewed the physiological mechanism underlying spikelet degeneration, with focus on the roles of phytohormones in regulating the process. There are several hypotheses for the spikelet degeneration, such as resource limitation, self-organization, and primigenic dominance. However, convincing evidences are not enough to support the assumptions. Phytohormones including auxins, cytokinins, gibberellins, abscisic acid, and ethylene are involved in regulating spikelet degeneration in cereals. The new phytohormones of brassinosteroids and polyamines have been observed to suppress spikelet degeneration in rice. The interactions among or between plant hormones may play a more important role in regulating spikelet degeneration. However, the information on such interactions is very limited. Some agronomic practices, especially proper water and nitrogen management, could reduce spikelet degeneration but the mechanism underlying remains unclear. Further research is needed to understand the cross-talk among/between phytohormones on spikelet degeneration, to reveal the physiological and molecular mechanism in which phytohormones and their interactions regulate the degeneration of spikelets, to exploit approaches to decrease spikelet degeneration and to elucidate their mechanism.

关键词： rice(Oryza safiva) spikelet degeneration phytohormones brassinosteroids polyamines

Research Advances in High-Yielding Cultivation and Physiology of Super Rice

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Rice science 2012年第3期19卷 177-184页

作者： Fu Jing yang jian-chang Key Laboratory of Crop Genetics and Physiology of jiangsu Province Yangzhou UniversityYangzhou 225009China

In 1996,China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant ***,approximately 80 super rice varieties have been released and some of them show high grain yields of 12-21 t/hm2 in field *** main reasons for the high yields of super rice varieties,compared with those of conventional varieties,can be summarized as follows：more spikelets per panicle and larger sink size （number of spikelets per square meter）;larger leaf area index,longer duration of green leaf,greater photosynthetic rate,higher lodging resistance,greater dry matter accumulation before the heading stage,greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period;and larger root system and greater root ***,there are two main problems in super rice production：poor grain-filling of the later-flowering inferior spikelets （in contrast to earlier-flowering superior spikelets）,and low and unstable seed-setting ***,we review recent research advances in the crop physiology of super rice,focusing on biological features,formation of yield components,and population ***,we suggest further research on crop physiology of super rice.

关键词： super rice grain yield grain filling crop physiology

Performance in Grain Yield and Physiological Traits of Rice in the yangtze River Basin of China During the Last 60 yr

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Journal of Integrative Agriculture 2013年第1期12卷 57-66页

作者： ZHANG Hao CHEN Ting-ting LIU Li-jun WANG Zhi-qin yang jian-chang ZHANG jian-hua Key Laboratory of Crop Genetics and Physiology Education Department of Jiangsu Province/College of Agriculture Yangzhou University School of Life Sciences and State Key Laboratory of Agrobiotechnology The Chinese University of Hong Kong

Knowledge on the performance in grain yield and physiological traits is essential to understand the main yield-limiting factor and make strategies for breeding and crop management in rice （Oryza sativa L.）. This study investigated the changes in grain yield and associated physiological traits of rice in the yangtze River Basin of China during the last 60 yr. Thirteen mid-season indica and 12 japonica rice cultivars that were popularly used were grown in the field in 2008 and 2009. The grain yield and yield components, biomass, leaf area, leaf photosynthesis, root oxidation activity, and harvest index were examined. The results showed that grain yield and grain yield per day have progressively increased during the years and such increases are mainly attributed to the expanded sink size as a result of more spikelets per panicle, especially for the case of super rice. Both biomass and harvest index were increased with the improvement of cultivars. Increase in biomass for modern rice cultivars was associated with an enhancement of leaf area and photosynthesis, root dry weight, and root oxidation activity, although the indica super rice cultivars showed a lower leaf photosynthetic rate and root oxidation activity than the semi-dwarf cultivars during the grain filling period. Both indica and japonica super rice cultivars exhibited a low percentage of filled grains, which may limit their great yield potential. All the data suggested that grain yield have been substantially improved during the 60 yr of rice breeding in the yangtze River Basin. Expanded sink size, increased dry matter production and harvest index, and enhanced leaf area and photosynthesis, root dry weight, and root oxidation activity contribute to the improvement in grain yield. Increase in filling efficiency could realize the great yield potential in super rice.

关键词： rice yield performance grain filling physiological traits super rice

Grain yield and water use efficiency of super rice under soil water deficit and alternate wetting and drying irrigation

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Journal of Integrative Agriculture 2017年第5期16卷 1028-1043页

作者： ZHOU Qun JU Cheng-xin WANG Zhi-qin ZHANG Hao LIU Li-jun yang jian-chang ZHANG jian-hua jiangsu Key Laboratory of Crop Genetics and Physiology/Co-lnnovation Crops Yangzhou UniversityYangzhou 225009P.RChina School of Life Sciences and State Key Laboratory of Agrobiotechnology P.R.China Center for Modern Production Technology of Grain The Chinese University of Hong KongHong Kong

This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.

关键词： super rice soil water deficit alternate wetting and drying (AWD) grain yield water use efficiency

Deciphering the morpho–physiological traits for high yield potential in nitrogen efficient varieties(NEVs):A japonica rice case study

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Journal of Integrative Agriculture 2022年第4期21卷 947-963页

作者： ZHU Kuan-yu YAN Jia-qian SHEN Yong ZHANG Wei-yang XU Yun-ji WANG Zhi-qin yang jian-chang jiangsu Key Laboratory of Crop Genetics and Physiology/jiangsu Key Laboratory of Crop Cultivation and Physiology/jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009P.R.China Joint International Research Laboratory of Agriculture and Agri-product Safety Ministry of EducationYangzhou UniversityYangzhou 225009P.R.China

The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.

关键词： rice N-efficient varieties nitrogen use efficiency root morpho–physiological traits nitrogen translocation leaf morphology canopy structure

Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

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Journal of Integrative Agriculture 2023年第1期22卷 63-79页

作者： ZHOU Qun YUAN Rui ZHANG Wei-yang GU Jun-fei LIU Li-jun ZHANG Hao WANG Zhi-qin yang jian-chang jiangsu Key Laboratory of Crop Genetics and Physiology/jiangsu Key Laboratory of Crop Cultivation and Physiology/jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops College of AgricultureYangzhou UniversityYangzhou 225009P.R.China

Utilizing the heterosis of indica/japonica hybrid rice(IJHR)is an effective way to further increase rice grain *** application of nitrogen(N)fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield ***,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain *** purpose of this study was to clarify these *** rice cultivars currently used in rice production,an IJHR cultivar Yongyou 2640(YY2640),a japonica cultivar Lianjing 7(LJ-7)and an indica cultivar yangdao 6(YD-6),were grown in the field with six N rates(0,100,200,300,400,and 500 kg ha^(-1))in 2018 and *** results showed that with the increase in N application rates,the grain yield of each test cultivar increased at first and then decreased,and the highest grain yield was at the N rate of 400 kg ha^(-1)for YY2640,with a grain yield of 13.4 t ha^(-1),and at 300 kg ha^(-1)for LJ-7 and YD-6,with grain yields of 9.4–10.6 t ha^(-1).The grain yield and N use efficiency(NUE)of YY2640 were higher than those of LJ-7 or YD-6 at the same N rate,especially at the higher N *** compared with LJ-7 or YD-6,YY2640 exhibited better physiological traits,including greater root oxidation activity and leaf photosynthetic rate,higher cytokinin content in the roots and leaves,and more remobilization of assimilates from the stem to the grain during grain *** results suggest that IJHR could attain both higher grain yield and higher NUE than inbred rice at either low or high N application *** shoot and root traits of the IJHR contribute to its higher grain yield and NUE,and a higher content of cytokinins in the IJHR plants plays a vital role in their responses to N application rates and also benefits other physiological processes.

关键词： indica/japonica hybrid rice grain yield nitrogen use efficiency cytokinins non-structural carbohydrate root activity

Symptom of the Shrunk-Grain Panicle and the change Characteristics in Its Grain

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Agricultural Sciences in China 2008年第1期7卷 10-18页

作者： ZHANG Zu-jian LANG You-zhong PAN Mei-hong yang jian-chang ZHU Qing-sen Key Laboratory of Crop Genetics and Physiology of jiangsu Province Yangzhou University Yangzhou 225009 P.R.China

Over the past two years, an abnormal growth phenomenon jiangsu Province of China. The phenomenon is described in called shrunk-grain panicle has occurred in a large area in details by figures and characters in this article. The method with a japonica rice Wuyujing 3 as the experimental material, the characteristics of grain morphology distribution and the grain weight were studied. Normal and shrunk-grain panicles were sampled from several representative areas. The length, width, and weight of the normal grains were distributed as regular, continuous, and single peaks. Plant growth typically had a right-leaning tendency. On the contrary, the distribution of the grain morphology and weight were irregular and nearly double that of the shrunk-grain panicle. The proportion of the cumulative distribution in the two kinds of peaks was closely related to the degree of shrunk-grain panicle. The article discusses the phenomenon＇s symptoms, problems, and diagnosis.

关键词： rice japonica shrunk-grain panicle symptom grain weight distribution

Relationship Between Root Chemical Signals and Grain Quality of Rice

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Agricultural Sciences in China 2007年第1期6卷 47-57页

作者： yang jian-chang chang Er-hua ZHANG Wen-jie WANG Zhi-qin LIU Li-jun Key Laboratory of Crop Genetics and Physiology of jiangsu Province Yangzhou University Yangzhou 225009 PR. China

This study was designed to elucidate the relationship between root chemical signals and the quality of rice. Various rice genotypes were used. Zeatin （Z）＋ zeatin riboside （ZR）, abscisic acid （ABA）, 1-aminocylopropane -1-carboxylic acid （ACC）, and organic acids in roots during grain filling and the appearance quality, cooking/eating quality were investigated. The correlations among them were analyzed. The results showed that Z ＋ ZR concentrations in the roots at mid- and lategrain-filling stages were significantly and positively correlated with the gel consistency and alkali spreading value （r = 0.72^＊ - 0.90^＊＊）, whereas negatively correlated with the amylose content （r = -0.68^＊ - -0.78^＊＊）. ABA concentrations in roots at mid- grain-filling stage were significantly and negatively correlated with the gel consistency and alkali spreading value （r = -0.90^＊＊-0.91^＊＊）, and positively correlated with the amylose content （r = 0.87^＊＊）. ACC concentrations in root exudates at mid-grain-filling stage were very significantly correlated with the percentage of chalky grains and chalkiness （r = 0.97^＊＊ - 0.98^＊＊）, and those at late-grain-filling stage Were significantly correlated with chalkiness and chalky size （r = 0.69^＊ - 0.96^＊＊）. The more the malic acid and succinic acid exuded from roots for a cultivar, the greater the breakdown values and the smaller the setback values in the starch profile, and the results were reversed for a cultivar with more tartaric acid and citric acid exuded from roots during the grain-filling period. The cultivar with more lactic acid in exudates had smaller gel consistency and alkali spreading values, but had greater amylose content. When roots were treated with exogenous ZR, ABA, and ACC during grain filling, effects of the chemicals on the rice quality were consistent with the relationships of the endogenous hormones （Z ＋ ZR, ABA, and ACC） with the quality indexes. Using rape cake as organic fertilizer can increase the concentrations of mali

关键词： rice root chemical signals appearance quality cooking and eating quality