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[Objective] The present paper aimed to study the physiological changes and gene dynamic changes of rice under low temperature stress, which was helpful to analyze the physiological basis and molecular mechanism of rice response to low temperature stress, and laid a theoretical foundation for screening suitable rice variety with cold tolerance and studying how to improve the cold-tolerance inheritance of rice. [Method] Taking three rice varieties with different cold-tolerance levels, P427 ( strong cold-tolerance), Nipponbare (cold-tolerance), 9311 (cold-sensitivity) as testing materials, and using method of phenotype combined with physiochemical index, the paper studied the effect of 3 -4 °C low temperature stress on phenotype, chlorophyll content and electric conductivity, and used RNA-Seq to analyze enrichment pathways and the dynamic change of gene response to low temperature stress. [Result] The rice variety with strong cold-tolerance P427 showed strong adaptability to low temperature. It maintained higher chlorophyll content under low-temperature stress, and its chlorophyll content before low temperature treatment, on the third day of low temperature treatment, on the third day of recovery growth was 29. 64, 29. 30 and 27. 96 µgig, respectively. Its electric conductivity on the first day, third day, fifth day of low-temperature was 10. 39%, 13. 08% and 17. 04%, and its membrane system had the lightest damage. A large number of genes were differentially expressed in both cold tolerant and cold sensitive varieties under low temperature induction, and the number of differentially expressed genes ( DEGs) continued to increase with the extension of low temperature treatment time,but the number of specific DEGs in P427 decreased from 2408 to 1717. In addition, only 576 specific genes of P427 were differentially expressed from 1 days to 3 days under low temperature treatment. GO and KEGG enrichment analysis showed that the specific DEGs of P427 after low temperature treatment were mainly enriched in metabolic pathways such as biosynthesis of secondary metabolites, plant hormone signal transduction and phenylpropane biosynthesis. [ Conclusion] There may be differences in cold-tolerance response genes and regulatory mechanisms among cultivars with different cold tolerance. There was a set of cold-tolerance response genes in P427 cultivar with strong cold tolerance, which was different from that in Nipponbare and 9311. Plant hormone signal transduction and phenylalanine metabolism were significantly affected by low temperature stress in seedling rice. P427 may respond to cold tolerance of seedling rice through metabolic pathways such as biosynthesis of secondary metabolites, plant hormone signal transduction and phenylpropane biosynthesis pathway. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate the effects of different mineral conditioners on the soil properties of cadmium (Cd)-contaminated paddy fields and the Cd content of rice in Guangxi, so as to provide a reference basis for the utilization of paddy fields to produce safe rice. (Method) Calcium-magnesium-silicon conditioners A and B, calcium-silicon conditioner C and calcium-magnesium conditioner D(set up as treatments A, B, C and D, respectively) were selected to carry out Cd-contaminated field remediation and treatment experiments in a Cd-contaminated paddy field in Guangxi, and no n-conditioner was applied as control (CK). The pH, cation exchange capacity (CEC), total Cd and soil available Cd content, Cd content of rice roots, stems, leaves and seeds were determined at the rice maturity stage after the treatment to analyze the remediation and treatment effects of different mineral conditioners on Cd-contaminated paddy soils and the residual status of Cd in various parts of rice, and to analyze the correlation between soil total Cd content, CEC and pH and available Cd content. [Result] The application of mineral conditioner could significantly increase soil pH and CEC of Cd-contaminated paddy fields (P<0.05, the same as below), both of which were increased by 15.0% 16.6% and 20.4% -23.8% respectively compared with those of CK; And it could significantly reduce the Cd content in the available state of soil in Cd-contaminated paddy fields, which was decreased by 14.0%-19. 3% compared with that of CK. The soil available state Cd content of the paddy field after the application of mineral conditioners showed a significantly negative correlation with pH, and the correlation coefficient between the log In(pH) value of pH and the soil available state Cd content was 0. 4053; It showed a highly significantly negative correlation with CEC(P<0.01), and the correlation coefficient was 0.6326; With the increase in soil pH and CEC, the soil available state Cd content continuously decreased. The applications of mineral conditioners were all available in reducing the Cd content of rice roots, stems, leaves and seeds as well as the enrichment factor of Cd in the aboveground part of rice, in which the total Cd content of rice seeds was decreased by 35.9% 50.2%, and the enrichment factor of Cd in the aboveground part of rice (stems, leaves and seeds) was decreased by 19.5% -33.5%,32.1%-44.9% and 38.6%-52.6%, respectively. [Conclusion] The application of different mineral conditioners can significantly increase the pH and CEC of paddy soils, thereby reducing the Cd content in the active state of the soil, inhibiting the migration of Cd from the soil to the roots, stems, leaves, and seeds of rice, decreasing the Cd content in rice, and reducing the enrichment of Cd in the aboveground parts of rice (stems, leaves and seeds). [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to overexpress and purify rice cold stress response protein OsCML16 in Escherichia coli, and prepare OsCML16 protein antibody to provide antigen, and provide reference for further study of biological function of rice OsCML16 protein by using the antibody. 【Method】 At first, the transmembrane region of the target protein OsCML16 was analyzed online using TMHMM 2.0 software, and then the fragment of target gene was amplified by high fidelity PCR, the prokaryotic expression vector pET30a-OsCML16 was constructed by gene recombination method, and the recombinant plasmid was transformed into expression E.coli line BL21 (DE3). OsCML16 protein expression was induced by IPTG, and purified by affinity chromatography, then the authenticity of the protein sequence was verified by mass spectrometry. 【Result】 By analyzing the transmembrane region of OsCML16 protein, it was found that the protein did not contain transmembrane region, and it was suitable for heterologous expression of the full-length protein. The prokaryotic expression vector PET30A-OSCML16 was successfully constructed by linking OsCML16 gene to pET30a vector. The result showed that the target gene had no mutation site and could be used for expression of the target protein. Exogenous expression OsCML16 protein was analyzed by SDS-PAGE electrophoresis, and results showed that OsCML16 protein could be induced expression at 28 ℃.The fusion protein His6-OsCML16-His6 could be purified by affinity chromatography, and the 30 kD fusion protein was obtained successfully. The purified protein was validated by mass spectrometry, and a total of three peptides were identified as OsCML16 protein, indicating that the exogenously expressed protein was the OsCML16 protein. 【Conclusion】 The rice cold stress response gene OsCML16 was expressed in E.coli by prokaryotic expression method. The fusion expression protein His6-OsCML16-His6 was purified by affinity chromatography according to the histide-carrying label of the fusion protein, and the sequence of the protein was verified by protein spectroscopy. Rice OsCML16 protein can be used for antibody preparation and protein function study in the future. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to illustrate the potential utilization of the gene of resistance to bacterial blight and bacterial leaf streak, so as to provide reference for enriching genetic base of rice breeding.【Method】A total of 102 rice cultivars were used to screen by molecular marker for the gene xa5, which mediated the resistance for both for resistance to bacterial blight and bacterial leaf streak. The parents carrying xa5 gene and having good resistance to bacterial blight and bacterial leaf streak were used as resistant sources to cross with susceptible cultivated rice. Through pedigree method and molecular marker-assisted selection（MAS）, elite hybrid rice restorer lines were cultivated. The excellent restorer lines and sterile lines were combined with strong heterosis combinations to analyze the resistance and comprehensive agronomic traits of strong heterosis combinations.【Result】A total of 17 cultivars were screened, which carried xa5 gene from 102 rice germplasm resources（materials）. Among these cultivars, DP3, IRBB5, N36, N776, N777, N779 and P89 were well resistant to both bacterial blight and bacterial leaf streak. An elite line Y240-1 was selected from the cross between DP3 and 9311. Moreover, 998 R was crossed with elite individual Y240-1. With molecular MAS, an elite restorer line Yexiangzhan with xa5 was developed from the cross of 998 R and Y240-1, after multiple generations of selfing. Yexiangzhan was combined with sterile line Pingfeng A to produce an elite hybrid cultivar Pingfengyouxiangzhan, which showed higher resistance to bacterial blight and bacterial leaf streak in comparison with Pingfeng A. Pingfengyouxiangzhan was resistant to rice blast at moderate level and meet the 2nd class standard of fine quality issued by Ministry of Agriculture of China.【Conclusion】xa5 gene with resistance to bacterial blight and bacterial leaf streak of rice has partial dominant effect, which can be used for breeding improvement of hybrid rice; It is helpful to enrich and broaden the genetic basis of rice breeding by cultivating the superior hybrid combinations of rice with moderate resistance to bacterial blight and stripe disease with wild rice blood. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to evaluate the effects of reducing nitrogen fertilizer during Chinese milk vetch returning on photosynthetic characteristics, yield and quality of rice, to explore the potential of chemical nitrogen replacement in crop rotation of Chinese milk vetch and rice, so as to provide a scientific foundation for the production of high-quality rice.【Method】Based on years of positioning tests, a control group of no nitrogen fertilizer (CK) was used, and six treatments were set up, including conventional nitrogen application (100%N), Chinese milk vetch combined with 100%, 80%, 60% and 40% nitrogen application (marked as MV+100%N, MV+80%N, MV+60%N, MV+40%N) and no application of nitrogen fertilizer (control group, CK). Rice photosynthetic characteristics of chlorophyll content (SPAD value), net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) were measured during the heading stage, and rice quality was measured during the harvest stage.【Result】In comparison to CK, a combination of 100%, 80%, 60% and 40% nitrogen fertilizer applied to returning Chinese milk vetch could significantly increase the SPAD value, Pn, and Gs of rice (P<0.05, the same as below). The increases were 3.53%-7.29%, 10.98%-16.43% and 4.88%-14.63%, respectively. Rice yield and protein content were also significantly increased by 24.01%-41.85% and 7.38%-18.17%, respectively. Compared with conventional N application (100%N), the SPAD value and Pn of MV+100%N treatment were significantly higher than those of 100%N treatment. However, there were no significant differences in SPAD value, Pn, Gs, Ci and Tr in MV+80%N, MV+60%N and 100%N treatment (P>0.05, the same as below). In terms of rice yield and traits, yield of MV+100%N, MV+80%N and MV+60%N treatment increased by 12.06%, 7.72% and 6.64% compared with 100%N treatment, but the yield, effective spikes, panicle length, number of grains per panicle, 1000-grain weight and seed setting rate had no significant difference with 100%N treatment. In terms of quality characteristics, there were no significant differences in milling quality, appearance quality, nutritional quality of MV+100%N, MV+80%N, MV+60%N and 100%N treatments. However, the cooking quality of MV+80%N and MV+60%N treatments were significantly improved compared with 100%N treatments. The results of correlation analysis showed that returning Chinese milk vetch could improve rice yield trait through increasing SPAD value, Pn and Gs, thus, improving rice milling quality, cooking quality and nutrition quality.【Conclusion】Chinese milk vetch combined with 100%, 80%, 60% and 40% nitrogen application can significantly improve photosynthetic indexes and increase rice yield SPAD value, Pn and Gs. Chinese milk vetch combined with 80% and 60% nitrogen application can also improve the milling quality, cooking quality and nutrition quality of rice, thus providing reference for high quality rice production. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to clarify the relationship between rice flavor quality and nitrogen nutrient absorption and utilization, the genotypes of high nitrogen efficient and good taste value rice were selected.【Method】The excellent japonica rice varieties（strains） cultivated along the yellow area were used as the test materials, and the influence of nitrogen on different rice genotype rice quality and nitrogen absorption and utilization was studied by setting different nitrogen fertilizer levels. 【Result】The taste value of different genotypes rice showed high difference, which decreased with nitrogen application increasing. The taste value of no nitrogen fertilizer was the highest and up to 83.9. Protein and straight starches increased with nitrogen application increasing. The linear analysis showed a significant open downward parabolic relationship and was performed with the nitrogen application quantity and the taste value(r=0.998**). The milled rice rate and the whole head rice rate increased with the nitrogen amount increasing, and the chalky grain rate and the chalkiness decreased with the nitrogen amount increasing. The nitrogen use efficiency, nitrogen grain production efficiency and nitrogen harvest index differed greatly between genotypes. The excellent and high-efficient nitrogen rice genotypes represented by by xindao 89 and xinkedao 31 were generally manifested with good appearance quality and relative high nitrogen grain production efficiency, up to 56.44 kg/kg. The related analysis showed that the nitrogen grain production efficiency was significantly positively with the rice taste value and significantly negatively with the protein content. The nitrogen use efficiency was significantly negatively with the taste value, negatively with the chalky grain rice rate and chalkiness, and positively with the milled rice rate and the whole head rice rate. It showed that the taste quality of rice improved and the appearance quality decreased under the level of no or less nitrogen fertilizer.【Conclusion】The nitrogen grain production efficiency can be used as an important evaluation index of excellent quality and high nitrogen efficient rice breeding. Improving the nitrogen use efficiency may be more conducive to improving rice processing, appearance quality and rice yield level. Good quality with high nitrogen efficiency（high nitrogen grain production efficiency） and high yield with high nitrogen efficiency（high nitrogen use efficiency） can be used as important evaluation standards for excellent food taste rice breeding and high yield rice breeding, respectively. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to clarify the distribution of rice blast resistance genes Pib, Pi9, Pi2, Pi54 and Pish in Japonica rice varieties (lines) and the resistance levels of different genotype to rice blast. [Method] A total of 93 rice materials were assessed by artificial inoculation and screening of molecular markers tightly linked to 5 major resistance genes. [Result] Three, two and one resistance genes were found in 19 (20. 4%), 25 (26. 9%) and 28 (30. 1%) materials, respectively, and five resistance genes corresponding to markers were found in all varieties (lines). There were 49 (52. 7%), 16 (17. 2%), 8 (8. 6%), 31 (33. 3%) and 31 varieties (lines) (33. 3%) containing rice blast resistance gene Pib, Pi9, Pi2, Pi54 and Pish in 93 varieties (lines), and the genetic frequency of Pib was the highest within this collection. A total of six genotypes and gene combinations (Pi9, Pi54, Pib + Pi9, Pib + Pi2, Pib + Pish and Pi9 + Pi54) are applicable in the rice-breeding, due to the resistance to rice blast but with low distribution in the tested varieties (lines). [Conclution] The study provided a scientific basis for breeding rice cultivars with rice blast-resistance. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the effects of microbial agents combined with leaf barrier on the translocation and accumulation of Cd in rice, and provided important reference for the safe production of moderate and mild Cd contaminated farmland. [Method] The field experiment was adopted, organosilicon and chelated iron were selected as foliar control agents, combined with microbial agents, and a total of 6 treatments were set up in the field: conventional planting pattern ( CK), spraying on the leaf with organosilicone and EDD HA-Fe ( Y), microbial agents derived from Bacillus amyloliquefaciens and Enterobacter ludwigii as base fertilizer applied separately to soil ( Dl and D2), microbial agents derived from B. amyloliquefaciens and E. ludwigii applied separately to soil, meanwhile spraying on the leaf with organosilicone and EDDHA-Fe ( D1 + Y and D2 + Y) . [Result] ( i) Leaf spraying with organosilicone and EDDHA-Fe significantly reduced the content of Cd in leaves, decreased TF roct-maw , and increased the proportion of Cd in roots by 38. 3%, compared with the control. Foliar fertilizer could effectively prevent the translocation and accumulation of Cd to the shoot of rice. (ii) The two formulations of basal application of microbial agents had different effects on Cd accumulation in rice. Compared with the control, the content of Cd in different parts of rice was decreased by basal application of B. amyloliquefaciens, and t he variation of Cd proportion was small. Applying with E. ludu!igii, Cd content in leaves of rice decreased, and Cd content in stems and grains increased significantly, which were 2. 06 and 1. 17 times higher than those in control, respectively. Meanwhile, the accumulation of Cd in whole plant was increased by 9 . 8 % . ( iii) The accumulation of Cd in rice plants decreased and the distribution of Cd in different parts of rice was significantly changed by basal application of microbial agents combined with foliar fertilizer. When treated with Dl + Y, the proportion of Cd in grains was 1. 68 times higher than that in the control, and the proportion of Cd in roots was 63. 5 % equivalent to the control. The combination of microbial agent in B. amyloliquefaciens and foliar fertilizer could accelerate the translocation of Cd to the shoot and grains of rice. Wben treated with D2 + Y, the TF,root-straw of Cd decreased by 64. 5 % compared with CK, the root Cd content was 1. 57 times higher than that of the control, and the proportion of Cd in the root increased by 57 . 7 % . Cd was restricted to the root by the combination of the basal application of E. ludwigii and foliar fertilizer, so that limited Cd was transferred to the shoot of rice. [Conclusion] The application of B. amyloliquefaciens agents, combined with leaf spraying of organosilicone and EDD HA-Fe can reduce the accumulation of Cd in the root and increase the transfer of Cd to the shoot of rice. Combined application of E. ludwigii and foliar fertilizer can effectively reduce the accumulation of Cd in the straw and grain of rice, which is one of the important measures for the safety production of medium and mild Cd contaminated farmland. [ABSTRACT FROM AUTHOR]

[ Objective] In this paper, the endophyte and rice blast infected rice ( Oryza sativa L ) Liaoxing 1 seedlings were used as tested materials to explore whether Suaeda salsa endophyte ( EF0801) could improve rice seedlings tolerance to rice blast. [ Methods] Morphological indicators, photosynthetic pigment content, defensive enzyme activity, MDA content and chlorophyll fluorescence parameters of rice seedlings with endophyte( EF0801) and/ or rice blast were determined. [Results] Rice-blast infection significantly decreased Chlb content, inhibited the photosystem ll ( PSll) oxygen-evolving complex, altered the electron transfer, decreased the photosynthetic efficiency and the photosynthetic perlormance index; After infection with rice-blast, the morphological indicators of seedlings with endophytic infection were better than those with endophytic uninfection, moreover endophytic infection increased the defensive enzyme activity, decreased MDA content, increased Cars content, as well as maintained PS II oxygen-evolving complex stability and normal electron transfer proceeds, meanwhile improved photosynthetic perlormance index and photosynthetic efficiency. [ Conclusion] Infection by endophytes ( EF0801) increased the activity of defensive enzymes in rice seedlings, reduced the content of MDA, alleviated the damage of rice-blast to PS II and improved the resistance of rice to riceblast. [ABSTRACT FROM AUTHOR]

[ Objective] This paper aimed to overcome the easy breakdown of conventional disease resistant plants. [ Method] A new kind of transgenic rice plant5 was generated based on Host Induced Gene Silencing ( HIGS) technology. [Results] SEC11, a key subunit of signal peptide complex in Magnaporthe oryzae, was selected for generating the HIGS expression vector by gateway technology. HIGS vector was transferred into the Japonica rice cultivar Nipponbare by agrobacterium mediated transformation to obtain transgenic rice plants. The spray assay with conidia of rice blast indicated that the HIGS transgenic rice plants were improved in rice blast resistance. [Conclusion] This study lays the foundation for molecular breading of rice blast resistant varieties with HIGS technology. [ABSTRACT FROM AUTHOR]

[Objective] The purpose of this paper was to clarify the effect of diversity mixed interplanting mode on rice photosynthesis, and provide a favorable basis for the further application of diversity mixed interplanting in the field. [Method] The rice varieties Gangyou 157 (main planted variety) and Huangkenuo (interplanted variety) were selected, and their relative chlorophyll content SPAD values and photosynthesis were measured under the mixed interplanting and mono-planting modes, and the occurrence and damage of rice blast and the agronomic characteristics of rice were investigated. [Result] When Gangyou 157 in the interplanting mode, the SPAD value of the inner row was significantly higher than that of the outer row and mono-planting treatments.There was no significant difference in the SPAD value of Huangkenuo under the two planting modes.The net photosynthetic rate of Gangyou 157 in the interplanting mode was significantly lower than that of the mono-planting treatment (decrease by 14.36%), and there was no significant difference when compared with the outer row. The transpiration rate, stomatal conductance and intercellular CO2 concentration were significant differences in all treatments. The net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration of Huangkenuo were not significantly different under the interplanting and mono-planting modes.Gangyou 157 and Huangkenuo had no significant difference in water use efficiency under interplanting and mono-planting modes. The rice blast disease index of Huangkenuo under the interplanting mode（2.79 ± 0.86） was significantly lower than that of the mono-planting（43.65 ± 6.11）,and its plant height under the interplanting mode（138.93±2.91）cm was significantly lower than that of the mono-planting（152.07 ± 2.27）cm, and the number of tillers of Huangkenuo under the mono-planting mode（9.75 ± 0.59） was significantly higher than that of the interplanting（7.04 ± 0.73）.There was no significant difference in disease index, plant height and tiller number of Gangyou 157 under the two planting modes. The yield per hectare of Huangkenuo under the diversity mixed-interplanting mode(6.23 t/hm² ) was significantly higher than that of the mono-planting model（4.50 t/hm²; the yield per hectare of Gangyou 157 under two planting modes was no significant difference. [Conclusion] Under the diversity mixed interplanting mode, the chlorophyll content of the main cultivars increased significantly, the photosynthetic rate decreased significantly, and other photosynthetic characteristics were no significant changes; the performance of the interplanted cultivars was not significantly different from that in the mono-planting mode. At the same time, the incidence of diseases of interplanted varieties was significantly reduced, without affecting the main varieties. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the effects of Cd stress on the absorption and transport of mineral elements in rice.[Method] 29 rice varieties were selected and treated with two groups (0,0.5 mg/kg). The contents of eight mineral elements (Ca, Fe, Zn, Mg, Cu, Mn, K,Na) in the upper and lower parts of rice were measured by atomic absorption flame spectrophotometer.[Result] In the underground part, compared with control group, the effect of Cd on Fe was shown to inhibit absorption; Zn, Mg, K and Na were resistant to Cd, and Zn was more resistant than Cu, and Cd was more competitive than Mn and Mg.Its Cd resistance and competitiveness were greater than that of Ca. Zhuzhen B and Japonica 7623 showed Cd tolerance among the eight mineral elements. [Conclusion] Zhuzhen B was the only rice variety that promoted the absorption of eight mineral elements after Cd stress; Liusha 1 was the least Cd-tolerant rice variety. [ABSTRACT FROM AUTHOR]

[ Objective] The present paper aimed to determine the effects of matriceson rice seedling quality, root morphology and nutrient ab sorption in the western of Liaoning. [Method] Taken rice variety Daohuaxiang as tested materials, and the differences of rice seedling mor phology, root morphology and nutrient absorption among five matrix treatments, such as the Shenyang Jinqiao matrix ( Ml), Fakuqifeng ma trix ( M2), Xinzhufeng biochar matrix ( M3), Liaoning Rice Research lnstirute matrix ( M4) and nutritional soil matrix ( M5) were com pared. [ Result] At weaning stage, the plants in M4 grew vigorously, accumulated a large amount of dry matter and had the best root morphol ogy and strongest uptake of nitrogen, while the M3 had the strongest uptake capacity of phosphorus and potassium. During the transplanting period, when the growth rate of seedlings by matrix was significantly accelerated, the plants in M4 had the highest root length, adventitious roots, root consolidation force, the accumulation of dry matter and nutrient absorption, especially for nitrogen. [Conclusion] The results sug gested that the matrix produced by Liaoning Rice Research Institute had the advantages of better seedling quality, greater root morphology and reasonable nutrient ratio. [ABSTRACT FROM AUTHOR]