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11 March 2011, Volume 25 Issue 2 Previous Issue    Next Issue
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Marker-Assisted Selection for Pyramiding Disease and Insect Resistance Genes in Rice PEI Qing-li ,＃,WANG Chun-lian ,＃,LIU Pi-qing ,WANG Jian ,ZHAO Kai-jun 2011, 25(2): 119-129 .  DOI: 10.3969/j.issn.1001-7216.2011.02.001 Abstract ( )   PDF (529KB) ( )   Blast (Magnaporthe grisea), bacterial blight (Xanthomonas oryzae pv. oryzae), brown planthopper (Nilaparvata lugens ) and white-backed planthopper (Sogatella furcifera) are major diseases and pests of rice. Utilization of rice varieties carrying resistance genes is one of the most economical, effective, and environment- friendly measures for the management of diseases and pests. The molecular markers, chromosome localization and the donor varieties of the identified disease/insect resistance genes of rice were summarized, and recent progress on molecular mapping of the resistance genes and on pyramiding different disease/insect resistance genes in rice by marker-assisted selection was reviewed. In addition, the strategy for developing better disease/insect resistant varieties was discussed.

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Phytochrome Functions in Rice Development GU Jian-wei ,LIU Jing ,XUE Yan-jiu ,ZANG Xin ,XIE Xian-zhi 2011, 25(2): 130-135 .  DOI: 10.3969/j.issn.1001-7216.2011.02.002 Abstract ( )   PDF (377KB) ( )   Phytochrome family mainly senses red and far-red light to regulate a range of developmental processes throughout the life cycle of plants. Rice phytochrome gene family is composed of three members known as PHYA, PHYB and PHYC. It has been elucidated that individual phytochromes display both unique and overlapping roles in rice photomorphogenesis by characterization of all rice phytochrome mutants including single mutants, all combinations of double mutants as well as triple mutant. Based on the published data and authors′ ongoing studies, current knowledge of rice phytochrome functions in regulating seedling deetiolation, root gravitropic response and elongation, plant architecture, flowering time and fertility is summarized. Additionally, the important issues in the field of rice phytochromes are proposed.

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Prokaryotic Expression of Polygalacturonase-Inhibiting Protein Gene (Ospgip1) from Rice and Bioinformatics Analysis of Its Coding Product CHEN Xi-jun ,LIU Xiao-wei ,ZUO Shi-min ,TONG Yun-hui ,PAN Xue-biao ,XU Jing-you 2011, 25(2): 136-142 .  DOI: 10.3969/j.issn.1001-7216.2011.02.003 Abstract ( )   PDF (1297KB) ( )   According to the sequences of GenBank and relative references, a fragment of 930 bp including the total open reading frame of Ospgip1 gene was amplified. Prokaryotic expression product of the gene could inhibit the growth and polygalacturonase (PG) activity of Rhizoctonia solani, the pathogen of rice sheath blight. Bioinformatics analysis showed that OsPGIP1 was a hydrophobic protein with a molecular weight of 32.8 kDa and a pI of 7.26. The protein was mainly located in the cell wall of rice, and the splice site of its signal peptide was between the 17th and 18th amino acid residue. There were four cysteines in the N- and C-terminal of the deduced amino acid sequence, respectively, forming three disulfide bonds (Between 56th and 63rd, 278th and 298th, 300th and 308th amino acid residue, respectively). The main structural elements of the deduced protein, which showed the typical leucine-rich repeat(LRR) modular organization, were α-helix, β-sheet and irregular circle. Comparing to PGIPs of other plants, the 7th LRR of this protein was absent. The nine LRRs could form a cleft which would be the activity site domain between the protein-protein interaction of the PGIP from rice and PG from the pathogenic fungi.

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Proteomics Analysis of Nutrient Stress Effect on Rice Leaf Senescence at Grain Filling Stage XIE Jin-shui ,SHAO Cai-hong ,TANG Xiu-ying ,SHI Qing-hua 2011, 25(2): 143-149 .  DOI: 10.3969/j.issn.1001-7216.2011.02.004 Abstract ( )   PDF (933KB) ( )   In order to reveal the molecular senescence mechanism of rice under nutrient stress at grain filling stage, the protein expression profile of functional leaves in hybrid rice Weiyou 916 was investigated by the approach of proteomics. Proteins were extracted from rice flag leaf and separated by two-dimensional gel electrophoresis. Thirty-four differentially expressed proteins were obtained, among which 26 were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and categorized into four groups of functions: 11 proteins were associated with photosynthesis, four proteins were associated with respiration, 10 proteins were related to antioxidative pathways and signal transmitting and one protein was putative protein. The functions of these 26 proteins were analyzed and the conclusion could be drawn from the following results: under nutrient stress conditions, photosynthesis and respiration of rice leaf declined significantly; proteins associated with antioxidative pathways decreased in expression abundance, and proteins associated with active oxygen synthesis and signaling showed drastical increase in expression abundance, which resulted in reduced resistance and accumulated active oxygen, consequently accelerated rice senescence process.

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Identification and Genetic Mapping of a Lesion Mimic Stripe Mutant in Rice MA Jian-yang,CHEN Sun-lu,ZHANG Jian-hui,DONG Yan-jun ,TENG Sheng 2011, 25(2): 150-156 .  DOI: 10.3969/j.issn.1001-7216.2011.02.005 Abstract ( )   PDF (1785KB) ( )   A lesion mimic stripe mutant was obtained from the M2 progeny of a japonica variety Jiahua 1 by 60Co γ radiation,temporarily designated as lms1 (lesion mimic stripe 1). The mutant displayed lesion mimic in its whole life, and belonged to propagation type. Physiological and histochemistry analysis suggested that the mutant displayed a phenotype of white stripe at a high temperature (30℃) and lesion mimic caused by cell initiative death at a low temperature(20℃)，respectively. The genetic analysis indicated that the mutant trait was controlled by a single recessive nuclear gene. In addition, using SSR markers and an F2 segregating population derived from two crosses(lms1/9311 and Pei’ai 64S/lms1), the lms1 gene was mapped between Indel1 and MM0112-4 with a physical distance of 400 kb on chromosome 6 in rice.

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QTL Mapping and Epistatic Analysis of High-Order Tillering in Rice (Oryza sativa) JIANG Hua ，#,ZHAO Jiang-hong ，#,GUO Long-biao ,JIANG Liang ,XUE Da-wei,ZENG Da-li,QIAN Qian,SUN Guo-chang 2011, 25(2): 157-162 .  DOI: 10.3969/j.issn.1001-7216.2011.02.006 Abstract ( )   PDF (2674KB) ( )   High-order tillering (HOT) is a common phenomenon in rice production, which is an important syndrome of rice domestication. Two different doubled haploid populations, one derived from a cross between Jingxi 17 and Zhaiyeqing 8 and the other from a cross between Chunjiang 06 and TN1 (herein designated as ZJDH and TCDH, respectively) were used to study genetic characteristics of high-order tillering. By using composite interval mapping, three QTLs (qHOT3, qHOT6-1 and qHOT8) located on chromosomes 3, 6 and 8 in ZJDH population, and two QTLs on chromosomes 6 and 12 in TCDH population, respectively were detected. Meanwhile, four and seven pairs of epistatic loci affecting HOT were mapped in ZJDH and TCDH, respectively. Furthermore, comparative analysis of two QTLs qHOT6-1 and qHOT6-2, which were located on chromosome 6 in the two populations, respectively indicated that the related quantitative trait loci may be identical to each other. And chromosome 6 may play an important role in high-order tillering.

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QTL Detection for Rice Grain Shape Using Chromosome Single Segment Substitution Lines LI Sheng-qiang,CUI Guo-kun,GUAN Cheng-ran,WANG Jun,LIANG Guo-hua* 2011, 25(2): 163-168 .  DOI: 10.3969/j.issn.1001-7216.2011.02.007 Abstract ( )   PDF (711KB) ( )   Rice grain shape is one of the important factors affecting grain quality and yield but it is liable to be influenced by genetic background and environment. The chromosome single segment substitution lines (SSSLs) in rice have been considered as ideal populations to identify quantitative trait loci (QTLs). Twenty-two QTLs affecting grain shape were detected and distributed on eight chromosomes except chromosomes 6, 9, 11 and 12 by using SSSLs. Among them, seven QTLs conditioned grain length, six conditioned grain width, five affected grain length-width ratio and four controlled grain thickness. The results supplied useful information for the QTL cloning and molecular breeding of rice grain shape.

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Improvement of Rice Bacterial Blight Resistance of Hua 201S, an Elite Photo-Thermo- Sensitive Genic Male Sterile Line, by Molecular Marker-Assisted Selection LAN Yan-rong#,WANG Jun-yi#,WANG Yi,MOU Tong-min* 2011, 25(2): 169-174 .  DOI: 10.3969/j.issn.1001-7216.2011.02.008 Abstract ( )   PDF (466KB) ( )   Hua 201S is an elite photo-thermo-sensitive genic male sterile(PTGMS) line, which was used for developing two-line hybrid rice. A bacterial blight resistant breeding line ‘Huahui 20’ containing Xa21 and Xa7 genes as donor parent was crossed with Hua 201S. F1 was backcrossed to Hua 201S for three times. The BC3F1 progenies were advanced to BC3F3 by selfing. The primers PTA248 for Xa21 and STSP3 (genetic distance to Xa7 is 0.9 cM) for Xa7 were used for molecular marker-assisted selection in each progeny. The fertility alterations, main agronomic traits and growth durations of the four selected lines YR7009(Xa21), YR7014(Xa21), YR7016(Xa7) and YR7023(Xa7/Xa21) were similar to the recipient parent Hua 201S. YR7009(Xa21) and YR7014(Xa21) were resistant against four Xanthomonas oryzae pv. oryzae（Xoo） strains, PXO61,PXO99, ZHE173 and GD1358, but not resistant against two Chinese strains, FuJ and YN24. YR7016(Xa7) and YR7023(Xa7/Xa21) were resistant against all the six Xoo strains tested. It showed that Xa21 and Xa7 were introgressed into the PTGMS line Hua 201S, improving the resistance against rice bacterial blight.

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SSR Marker-Based Diversity Analysis on Rice Landraces Currently Planted by the Bulang Minority in China DONG Chao,XU Fu-rong ,YANG Wen-yi ,ZHANG En-lai ,YANG Ya-yun ,TANG Cui-feng ,A Xin-xiang ,DAI Lu-yuan 2011, 25(2): 175-181 .  DOI: 10.3969/j.issn.1001-7216.2011.02.009 Abstract ( )   PDF (701KB) ( )   Eighty accessions of rice landraces being planted by the Bulang Minority were collected and used in diversity analysis by using 72 pairs of SSR primers distributed on 12 chromosomes. As the results, 271 alleles with an average of 3.764 per locus, and 197 effective alleles with an average of 2.739 per locus were detected. The polymorphism information content ranged from 0.163 to 0.827 with an average of 0.582. Twenty rare alleles were discovered. The genetic diversity of rice landraces differed among the three counties where the Bulang minority lives. The genetic diversity of Menghai County was the highest, followed by Shuangjiang County and Mojiang County. The similarity coefficient of rice landraces varied from 0.111 to 0.875 with an average of 0.411. All the rice landraces used might be clustered into indica group and japonica group at the similarity coefficient of 0.266. However, the rice landraces grown in one region failed in being clustered into one subgroup completely. This indicates that environmental and social factors in one region where the Bulang Minority lives have limited influence on evolution of the rice landraces in the region. In addition, the possible reasons and contribution to the rice landrace diversity by the Bulang minority were discussed. Some suggestions were put forward to avoid the landraces with one name but different ones or one landrace but with more than one name during collection.

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Effects of Plant Hormones in Regulating Sucrose Synthase Activity and Grain Filling of Rice TANG Tang,XIE Hong,LU Bing,LIANG Jian-sheng 2011, 25(2): 182-188 .  DOI: 10.3969/j.issn.1001-7216.2011.02.010 Abstract ( )   PDF (1708KB) ( )   In order to explore the mechanisms of hormones in the regulation of grain filling, the changes in contents and activities of enzymes which catalyze sucrose metabolism and endogenous hormones in grains during grain filling were analyzed by using inter-subspecies hybrid rice combination Liangyoupeijiu and intervarietal hybrid rice combination Shanyou 63 as materials. Results showed that superior grains had higher contents of endogenous indole-3-acetic acid (IAA), zeatin riboside (ZR) and abscisic acid (ABA) compared with inferior grains at early grain filling stage, and the contents of IAA, ZR and ABA were positively and significantly correlated with the maximum and mean grain filling rate, grain filling percentage, and grain weight. The sucrose synthase (SuSase) activity in superior grains was higher and peaked earlier than that in inferior grains. The grain filling rate, grain filling percentage, grain weight and starch accumulation rate were positively and significantly correlated with the SuSase activity in grains. Application of low concentration of ABA at 8 d after flowering significantly increased endogenous ABA content and SuSase activity in grains, grain filling percentage, and final grain weight. On the contrary, when fluridone (an inhibitor of ABA synthesis) was applied, the ABA content and the activity of SuSase decreased. These results suggest that ABA plays a significant regulatory role in grain filling largely through affecting sucrose synthase activity.

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Plant Type and Dry Matter Production Characteristics of C Liangyou Hybrid Rice Combinations TANG Wen-bang,ZHANG Gui-lian,XIAO Ying-hui,DENG Hua-bing,FAN Ke,LIU Guo-hua,CHEN Li-yun* 2011, 25(2): 189-194 .  DOI: 10.3969/j.issn.1001-7216.2011.02.011 Abstract ( )   PDF (393KB) ( )   The plant type and dry matter production characteristics were studied by using three C Liangyou hybrid rice combinations as materials and Shanyou 63 as a control. Comparing to Shanyou 63, the C Liangyou hybrid rice combinations showed narrower and longer uppermost three leaves, narrower leaf angles and larger total leaf area; maintained stronger root vigor and higher net photosynthetic rate and contents of chlorophyll at the full heading stage; had shorter and wider base internodes and stronger lodging resistance, longer middle internodes, and a long uppermost internode occupying 42.77% of total stem length; displayed more photosynthate accumulation and greater transportation ability. The dry matter exportation and dry matter accumulation in stem and leaves after heading significantly and positively correlated with the grain yield for the C Liangyou hybrid rice combinations. Ideal plant type, stronger dry matter production and transportation ability at the middle and late growth stage are the main cause leading to high yield of the C Liangyou hybrid rice combinations.

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Effects of Rhizosphere Dissolved Oxygen and Nitrogen Form on Root Characteristics and Nitrogen Accumulation of Rice ZHAO Feng ,# ,XU Chun-mei ,# , ZHANG Wei-jian ,ZHANG Xiu-fu ,CHENG Jian-ping ,WANG Dan-ying 2011, 25(2): 195-200 .  DOI: 10.3969/j.issn.1001-7216.2011.02.012 Abstract ( )   PDF (813KB) ( )   Dissolved oxygen and N forms have important effects on rice root growth and N availability. Indica hybrid rice Guodao 1 and conventional japonica rice Xiushui 09 were cultured for six weeks in hypoxic nutrient solution with NH4NO3 or (NH4)2SO4 as nitrogen source; Four weeks later, Guodao 1 was transferred to the split-root system at different dissolved oxygen contents (DOTs). The biomass, root morphological traits and nitrogen accumulation were investigated. Under lower rhizosphere oxygen (DOT 0 to 1.0 mg/L), NH4NO3 -N significantly increased the plant biomass in comparison with sole NH4+ -N, about 69% in Guodao 1 and 41% in Xiushui 09. In addition, the root number, the longest root length, the root dry weight and the root activity for Guodao 1 and Xiushui 09 were also increased under NH4NO3-N nutrition. NH4NO3-N enhanced the N accumulation in roots and shoots of Guodao 1 by 60% and 52%, in roots and shoots of Xiushui 09 by 41% and 33%, respectively. In the split-root system, because of increased rhizosphere oxygen (DOT 8.0 to 9.0 mg/L), the root biomass was increased by 21.6%, the root number by 27%, the longest root length by 14% and the root volume by 10%. The N accumulation in roots was enhanced by 11% under higher rhizosphere oxygen. In conclusion, improvement of dissolved oxygen and ammonium-nitrate N source have positive effect on the root growth and N accumulation of rice plants.

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Analysis on Grain Quality of Indica Hybrid Rice Combinations Bred During Recent Twenty-Five Years in China MIN Jie,ZHU Zhi-wei,JIN Lian-deng,XU Li,ZHANG Lin-ping,TANG Sheng-xiang 2011, 25(2): 201-205 .  Abstract ( )   PDF (354KB) ( )   To understand the grain quality of indica hybrid rice combinations in China and to clarify its key points for genetic improvement for the future, ten grain quality traits and their superior quality rates (SQRs) of 4495 indica hybrid rice combinations bred since 1984 were analyzed. The SQRs of the ten grain quality traits were from 34.2% to 97.9%, with an average of 78.5%. The excellent indica hybrid rice combinations with all the five key grain quality traits (head rice rate, chalkiness degree, transparency degree, amylose content and quality index) in or above the standards of the third class superior quality of rice occupied 29.9% of the total. The average SQRs for the ten grain quality traits of the tested combinations bred in the three periods, 1980s, 1990s and 2001-2008, were 64.2%, 71.1% and 81.4%, and the SQRs for quality indices were 84.5%, 86.4% and 88.5%, respectively. The excellent indica hybrid rice combinations bred in 2001-2008 with all of the five key quality traits in or above the standards of the third class superior quality occupied 32.9%, 18.0 and 11.9 percent points higher than that in 1980s and 1990s. The above results indicated that in general, the grain quality of the indica hybrid rice combinations bred in 2001-2008 was better than that in 1980s and 1990s. The tested combinations of Boyou-, Zhongyou- and Peiyou-series showed better grain quality. On the other hand, it was noticed that the SQRs of chalky grain rate and chalkiness degree were rather lower (only 34.2% and 55.1%, respectively) than that of other eight quality traits，which would be the emphasis of grain quality improvement of indica hybrid rice in recent future.

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Studies on Biological Characteristics and Pathogenicity Differentiation of Rice Sheath Blight Pathogen from Three Provinces in South China ZOU Cheng-jia#,TANG Fang# ,YANG Mei,HE Xiao-xia,LI Xian-jun,ZHOU Er-xun* 2011, 25(2): 206-202 .  DOI: 10.3969/j.issn.1001-7216.2011.02.014 Abstract ( )   PDF (499KB) ( )   In order to elucidate the relationship among the biological characteristics, pathogenicity and geographic origin of isolates of Rhizoctonia solani, the causal agent of rice sheath blight, so as to provide evidences for controlling the disease in South China, with a total of 335 isolates of R. solani collected from 33 counties of 3 provinces (Guangdong, Guangxi and Hainan) in South China, cultural characteristics (hyphal growth rate, colony colour and sclerotium number), hyphal anastomosis groups, number of hyphal cell nuclei and pathogenicity differentiation were investigated. The hyphal growth rates could be divided into three types, i.e. slow, moderate and fast, with isolate numbers of 3, 136 and 196, which accounted for 0.90%, 40.60% and 58.50% of the total isolates, respectively. The number of sclerotia produced on PDA medium in all the isolates could be divided into four different types, i.e. absence or rare, less, moderate and abundant sclerotia, which accounted for 1.19%, 17.61%, 71.04% and 10.15% of the total isolates, respectively. The anastomosis grouping confirmed that all the tested isolates belonged to AG-1ⅠA of R. solani. The hyphal cell nuclear numbers of the 50 randomly selected isolates were between 7 and 13. The 270 tested isolates could be divided into only two pathotypes, i.e. moderate and high virulence with isolate numbers of 208 and 62, which accounted for 77.04% and 22.96%, respectively, no isolate with weak virulence was found. Taken together, the results revealed that there existed differences in pathotype and hyphal growth rate as well as the number of sclerotia among the tested isolates, showing more diversity.

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Effects of Solution Surface Tension and Spray Methods on Deposition of Droplets on Rice Plants XU De-jin,GU Zhong-yan*,XU Guang-chun,XU Xiao-long,FAN Peng 2011, 25(2): 213-218 .  DOI: 10.3969/j.issn.1001-7216.2011.02.015 Abstract ( )   PDF (1292KB) ( )   By taking biological dye ponceau-G as tracer, the colorimetric method was adopted to analyze the effect of solution surface tension and spray methods on deposition rate of droplets on rice plants. The critical surface tensions of rice leaves at the tillering, booting and flowering stages were 34.46, 34.36 and 34.33 mN/m, respectively. Contrasting with only spraying clean water, the increase of deposition rate of ponceau-G on single rice plant varied among the three growth stages after spraying the ponceau-G solution supplemental with 100 mg/L TX-10 on rice plants. The deposition rate by top spray method with a manual sprayer increased by 80.85%, 29.80% and 22.61%, respectively. And the deposition rate by tilting spray method with a mist sprayer increased by 50.83%, 18.48% and 31.07%, respectively. By spraying the solution with same surface tension on the plants at the same stages, the deposition rate of ponceau-G on single rice plant by tilting spray method with a mist sprayer was much higher than that by drifting spray method with a mist sprayer and by top spray method with a manual sprayer. It will help to increase the deposition rate of droplet on rice plants to adopt mist sprayer and surfactant which may reduce the surface tension of solution for spraying pesticide in paddy fields.

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Model-Based Analysis on the Pollen Viabilities of Transgenic Rice B2 at Different Temperatures LIU Shou-dong,SHI Pei-jian,JIANG Xiao-dong,YAO Ke-min,HU Ning* 2011, 25(2): 219-222 .  DOI: 10.3969/j.issn.1001-7216.2011.02.016 Abstract ( )   PDF (719KB) ( )   The pollen viability of a genetically-modified japonica rice, B2, containing bar gene with herbicide Basta resistance was investigated under nine temperatures(5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, and 45℃) by 2,3,5-triphenyl tetrazolium chloride (TTC) method in vitro after 0, 1, 2, 3, 4, 5, 6, 8, 12, and 14 min from anther. The result showed that the pollen viability decreased with the passing time in vitro, like as “S curve”, which could be accurately described by the Logistic equation. In vitro pollen viability first increased and then decreased with the rising temperature. The optimal temperature for pollen viability ranged from 20℃ to 30℃, and 25℃ was the most optimum temperature. High temperature stress on the pollen viability was more obvious than low temperature. Two equations, an exponential one and a Logistic one, could give the satisfied predicts of the pollen viability duration and pollen longevity, helping to estimate the risk of transgenic flow.

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A Dwarf Disease on Rice in Hubei Province, China is Caused by Southern Rice Black-Streaked Dwarf Virus ZHANG Song-bai ,LUO Han-gang ,ZHANG Qiu-dong ,ZHANG Chang-qing ,WU Zu-jian ,XIE Lian-hui 2011, 25(2): 223-226 .  DOI: 10.3969/j.issn.1001-7216.2011.02.017 Abstract ( )   PDF (485KB) ( )   Recently, the epidemic of rice black-streaked dwarf disease caused by rice black-streaked dwarf virus or southern rice black-streaked dwarf virus has caused great yield losses in rice production in South China and East China. However, the occurrence of this disease in Hubei Province, China has not been reported. In 2009 and 2010, a rice dwarf disease, similar to rice black-streaked dwarf disease, caused great rice yield losses in some counties of Hubei Province along the Yangtze River. By symptom observation, dsRNA profiling and RT-PCR, the pathogen of the rice dwarf disease was identified as southern rice black-streaked dwarf virus(SRBSDV). This indicates that SRBSDV has been spread from the south to the central rice-growing area of China by the insect vector Sogatella furcifera.

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Difference of Pesticide Residue in Grains Among Rice Cultivars YING Xing-hua,XU Xia,YANG Shi-hua*,ZHU Zhi-wei,CHEN Ming-xue,WANG Lei,CHENG Ben-yi,XIA Jun-hui 2011, 25(2): 227-230 .  DOI: 10.3969/j.issn.1001-7216.2011.02.018 Abstract ( )   PDF (623KB) ( )   Pesticide (Triazophos and Chlorpyrifos) residue in grains was measured with eighteen early indica rice cultivars with similar growth and developmental period. The results showed that the pesticide residue in grains of the eighteen cultivars varied significantly. The pesticide residue varied between pesticides and different parts of rice grains, showing the following order: triazophos> chlorpyrifos, and chaff>milled rice. Three rice cultivars with low pesticide residue (Zhongzao 39, Yongxian 703 and Jiayu 76) were selected.