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10 January 2011, Volume 25 Issue 1 Previous Issue    Next Issue
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Research Letter
研究报告
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Research Letter

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Systematic Identification of Rice ABC1 Genes and Their Expression Analysis under Abiotic Stresses GAO Qing-song,ZHANG Dan,XU Liang,XU Chen-wu* 2011, 25(1): 1-10 .  DOI: 10.3969/j.issn.1001-7216.2011.01.001 Abstract ( )   PDF (3769KB) ( )   ABC1 (Activity of bc1 complex) family belongs to protein kinase families, whose members widely exist in prokaryotes and eukaryotes. It has been reported that several plant ABC1 genes participate in abiotic stress response. To understand the structure and function of ABC1 genes in rice, the systematic characterization of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes were performed. A total of 15 and 17 members of rice and Arabidopsis ABC1 families were identified by the bioinformatics method. The phylogenetic analysis of these proteins suggested that divergence of this family had occurred and the main characteristics had established before the dicotmonocot split; speciesspecific expansion contributed to the evolution of this family in rice and Arabidopsis after the split of monocots and dicots. Intron/exon stucture analysis indicated that most of the orthologous genes had similar exon sizes but diverse intron sizes and the rice genes contained more large introns; intron gain was an important event accompanying the recent evolution of rice ABC1 family. Multiple sequence alignment revealed one conserved amino acid segment and four conserved amino acids of the ABC1 domain. Online subcellular localization predicted that nine rice ABC1 proteins were localized in the chloroplast. Realtime RTPCR assay established that rice ABC1 genes expressed primarily in leaves and could be modulated by a broad range of abiotic factors such as H2O2, abscisic acid, low temperature, drought, darkness and high salinity. These results illustrate that rice ABC1 family played roles not only in the environmental stress response but also likely in the specific biological process of rice.

研究报告

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hrcQ Gene Determines Xanthomonas oryzae pv. oryzicola to Trigger Hypersensitive Response in Nonhost Tobacco and Pathogenicity in Host Rice ZHANG Ding-ding,ZOU Li-fang,ZHAO Mei-qin,ZOU Hua-song,CHEN Gong-you 2011, 25(1): 11-18 .  DOI: 10.3969/j.issn.1001-7216.2011.01.002 Abstract ( )   PDF (904KB) ( )   hrcQ gene of Xanthomonas oryzae pv. oryzicola (Xoc) is highly conserved in the animal and plant pathogens. It has been postulated that the differentiation at the Nterminal of HrcQ proteins in different plant pathogenic bacteria is related to the secretion of specific effectors through type Ⅲ secretion system (T3SS). However, it is unclear whether HrcQ affects the formation of T3SS and the secretion of T3SS effectors. To understand the effect of HrcQ on the formation of T3SS and the secretion of T3SS effectors, hrcQ mutant of Xoc was generated by knockingout mutagenesis through allelic exchange. Pathogenicity assays verified that the hrcQ mutant lost the ability to trigger hypersensitive response (HR) in nonhost tobacco and pathogenicity in host rice. The expression of hrcQ was induced when the pathogen interacted with rice cells. The proteinprotein interaction assay by yeast twohybrid system showed that HrcQ could interact with Hpa1, HrcN, HrpB5 and HrpB2. Immunobloting assay confirmed that HrcQ was not secreted through T3SS, whereas the mutation of hrcQ led to no secretion of Hpa1 and HrpB2 through T3SS. These results suggest that HrcQ is the core component of T3SS helping Hpa1 and HrpB2 secret through T3SS to determine HR in tobacco and pathogenicity in rice.All the above also provides a basis for further understanding of the secretion mechanisms by X. oryzae pv. oryzicola T3SS.

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Construction of Molecular Fingerprinting Database and Dual PCR Assay for Two Indica Rice Hybrids and Two Japonica Rice Varieties by Using SSR Markers CHEN Shu-lin,WANG Hai-yan,DING Zhen-qian,WANG Xiu-e,CHEN Zhong-ming 2011, 25(1): 19-24 .  DOI: 10.3969/j.issn.1001-7216.2011.01.003 Abstract ( )   PDF (558KB) ( )   A total of 460 SSR primers were used for amplification of five indica hybrid rice combinations and their parents, and 16 japonica rice varieties (or elite lines). By using the identified codominant specific primers, molecular fingerprinting databases for Guodao 6, Liangyoupeijiu,Yandao 8 and Xudao 4 were constructed. A total of 5, 3, 1 and 2 SSR primers were identified to be specific for Guodao 6, Liangyoupeijiu, Yandao 8 and Xudao 4, respectively. These fingerprints can be used to examine the seed purity of these rice varieties. In addition, to develop dual PCR assay in examination of seed purity and authenticity, SSR primers which could stably amplify clear bands and have good specificity were selected and used in multiplex popymerase chain reaction amplification.

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Development of STS Marker Linked to Rice Blast Resistance Gene Pi9 in Marker Assisted Selection Breeding YIN De-suo,XIA Ming-yuan,LI Jin-bo,WAN Bing-liang,ZHA Zhong-ping,DU Xue-shu,QI Hua-xiong* 2011, 25(1): 25-30 .  DOI: 10.3969/j.issn.1001-7216.2011.01.004 Abstract ( )   PDF (1065KB) ( )   Indica rice line 751127 carrying broadspectrum rice blast resistance gene Pi9 was used as resistance gene donor for genetic improvement of Yangdao 6 and R6547. By alignment of genomic sequences from the Pi9 locus of 751127, Yangdao 6 and Nipponbare, codominant STS (sequencetagged site) marker PB91, which linked to the Pi9 gene, was developed for molecular markerassisted selection (MAS). Eight backcross lines carrying Pi9 were obtained, among which four lines contained the genetic background of Yangdao 6 and the other four lines had the R6547 background. Under natural disease infection conditions in Enshi County and Yichang County of Hubei Province, China, the Pi9carrying lines showed higher blast disease resistance than Yangdao 6 and R6547 in various degrees. The hybrids originated from 08C893, an R6547derived rice line, showed higher blast disease resistance as compared to the control Yangliangyou 6. The results suggest PB91 is an effective codominant marker for MAS of Pi9 which is a valuable resistance gene for the control of rice blast disease in Hubei area.

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Efficient Selection of Fine Rice Quality Maintainer Lines with Functional Markers of Wx and fgr Genes CHEN Shen-guang,ZHOU Yi-feng,ZHAO Fei,JIN Liang,SHEN Sheng-quan 2011, 25(1): 31-36 .  DOI: 10.3969/j.issn.1001-7216.2011.01.005 Abstract ( )   PDF (497KB) ( )   According to the genotypes detected by two primers of functional markers, 484/485 (for Wx gene) and fgr1F/1R(for fgr gene), amylose contents and fragrance of 13 indica maintainer lines, Yixiang 1B was selected as good rice quality donor parent. The two markers were used to genotype the F2 individual plants derived from Ⅱ32B/Yixiang 1B. There were significant difference in electrophoretogram among individual plants, so that they were easy to distinguish, and these two markers showed independent inheritance. Superior individuals with fgr and Wx genotypeⅠ(same as Yixiang 1B) and Ⅲ (heterozygote) were selected. Then combined with the selection of agronomic and rice quality characters, the detection in selected plants or individual plants in F3 to F6 generations were carried out. In F6 generation, the plants were detected by 484/485 and fgr1F/1R again, advanced plants were obtained, which had stable characters, good plant type, obvious fragrance, medium amylose content and so on. Results of testcross showed that 75.5% plants were maintainer lines. It is suggested that detection and selection of maintainer lines of indica rice with functional markers of Wx and fgr genes in earlygeneration combined with conventional breeding could provide a rapid way to obtain good rice quality maintainer lines with fragrance, medium amylose content, slender grain shape, low chalkiness degree, high transparency and so on.

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Development and Application of Functional Markers for Polyphenol Oxidase (PPO) Alleles in Rice YANG Jie,CAO Qing,WANG Jun,FAN Fang-jun,ZHANG Yu-qiong,ZHONG Wei-gong 2011, 25(1): 37-42 .  DOI: 10.3969/j.issn.1001-7216.2011.01.006 Abstract ( )   PDF (768KB) ( )   The phenol reaction (PHR) phenotype is one of the criteria of rice classification and the gene controlling PHR has been identified. The positive PHR phenotype is conditioned by functional polyphenol oxidase(PPO) gene, and negative PHR phenotype is conditioned by nonfunctional PPO gene. To seek the markers for rice classification, two InDel markers, FMppo18 and FMppo29, were developed flanking on the 18 bp or 29 bp deletion in exon 3 of PPO alleles. Fortyfive rice materials were genotyped with the two markers and their PHR phenotypes were also investigated. Three accessions of wild rice and six indica rice varieties carried nondeletion functional PPO alleles. Among the 11 japonica rice materials, nine carried 18 bp deletion allele, and two carried 29 bp deletion alleles. However, the indica rice variety Dular carried 29 bp deletion allele and Longqing carried 18 bp deletion allele. Among the 23 weedy rice accessions, three accessions of Ludao collected from Lianyungang of Jiangsu Province, China, and four accessions of Tangdao collected from Huaiyuan, Laian, Quanjiao, and Feidong of Anhui Province, China in 1950s carried nondeletion PPO alleles. Among the 16 weedy rice accessions collected in recent years, 14 carried normal PPO alleles, and two carried 18 bp deletion PPO allele which was consistent with the cultivated rice in Jiangsu Province. These results showed that the positive PHR materials carried normal PPO alleles, and the negative PHR materials carried deletion PPO alleles, indicating that the phenotype perfectly matched with the genotype. Therefore, the two markers can be used in germplasm screening, markerassisted selection and evolution research in rice.

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Identification of QTLs for Rice Appearance Quality Traits Across Different Ecological Sites YANG Ya-chun,NI Da-hu,SONG Feng-shun,LI Ze-fu,YI Cheng-xin,YANG Jian-bo 2011, 25(1): 43-51 .  DOI: 10.3969/j.issn.1001-7216.2011.01.007 Abstract ( )   PDF (881KB) ( )   Two rice varieties, Nipponbare (japonica) and 9311 (indica), whose whole genomes have been sequenced, were used as parents to create a recombinant inbred lines population consisting of 190 lines by single seed descent method. The genetic linkage map was constructed with 178 SSR, CAP, and STS markers. Quantitative trait loci (QTLs) were identified for six rice appearance quality traits including chalky grain rate (CGR), chalky area (CA), chalkiness degree (CD), grain length (GL), grain width (GW), grain lengthwidth ratio (GLW) by composite interval mapping method in three different ecological sites (Lingshui, Hefei and Huaiyuan). A total of 39 QTLs were identified, with 6 to 7 for each trait, indicating that rice appearance quality traits were controlled by multiple genes. Eight QTLs were detected at 2 or 3 sites, among which qCD1 and qCD3 (explaining 288% and 321% of variance) were detected in all the three sites. Eleven QTLs were found to have pleiotropy in which a single QTL controlled 2 to 6 traits, and the interval of RM16-RM143 on chromosome 3 controlled the 6 traits. The comparison of QTL identification among the three sites showed that the environment effects were trait dependant. The QTLs for GLW and CD were comparatively stable across sites, whereas those for GW were sensitive to environment.

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Identification and Mapping of QTLs for Cold Tolerance at the Seedling Stage in Common Wild Rice(Oryza rufipogon) ZHENG Jia-xing,MA Zeng-feng,SONG Jian-dong,LIU Chi,LI Yong-tao,HUANG Da-hui,WEI Shao-li,ZHANG Yue-xiong,MI Ke,HUANG Jin-yan,CHEN Miao,MENG Jiao-rong,LI Rong-bai,CHEN Bao-shan 2011, 25(1): 52-58 .  DOI: 10.3969/j.issn.1001-7216.2011.01.008 Abstract ( )   PDF (1584KB) ( )   Two core accessions of common wild rice (DP15 and DP30) as donor parents and the cultivar 9311 as recipient parent were used to construct chromosome segment substitution lines for identification of QTLs for cold tolerance at the seedling stage and QTL effect analysis. A QTL mapping population from the most coldtolerant substitution line was constructed to map majoreffect QTLs with SSR markers. The two donor lines, DP15 and DP30, showed obvious difference in the number, location and effect of QTLs for cold tolerance. In the 230 BC4F2 substitution lines in which substituted chromosome segments covered the whole genome of the two donors, a total of 19 cold tolerance QTLs were detected, which distributed throughout all the 12 chromosomes, and clustered on chromosome 3 and chromosome 8. These QTLs were separated each other in different chromosome substitution lines. The substitution line with the smallest effect QTL for cold tolerance and the line with the largest effect QTL showed 8% and 74% of survival rate after cold treatment, respectively. A maineffect QTL, qSCT31, was mapped between SSR markers RM15031 and RM3400, near the centromere on the long arm of chromosome 3 with a distance of 18 cM to the closest linkage markers, RM15040 and RM1164.

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Changes in Carbohydrate Content and Protective Enzyme Activity of Japonica Type Super Rice During GrainFilling Stage in North China XU Ming,JIA De-tao,MA Dian-rong,MIAO Wei,WANG Nan,CHEN Wen-fu 2011, 25(1): 59-64 .  DOI: 10.3969/j.issn.1001-7216.2011.01.009 Abstract ( )   PDF (1741KB) ( )   The carbohydrate and malondialdehyde contents and protective enzyme activities in grains and leaves of rice during grainfilling stage were investigated in a pot experiment with typical japonica super rice varieties, Shennong 265 and Shennong 606 as materials and Akihikari and Liaojing 294 as control. The results showed that Shennong 265 and Shennong 606 had significant advantage in yield. Glucose, fructose and sucrose contents in leaves of Shennong 265 were significantly higher than the control Akihikari at 20 days and 40 days after flowering. At 40 days after flowering, starch content in grains of Shennong 265 was also significantly higher than that of the control Akihikari. Shennong 606 showed no significant difference compared with the control Liaojing 294 in carbohydrate contents in grains and leaves during grainfilling stage. Roots displayed early senescence in contrast to aerial parts, which was indicated by earlier peak of protective enzyme activity in roots than in leaves of japonica type super rice. Shennong 265 and Shennong 606 showed delayed senescence because their leaves and roots had low malondialdehyde content, high superoxidase dismutase activity and peroxidase activity compared with the control varieties.

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Effects of No-Tillage Cultivation on Some Population Characteristics of TwoLine Hybrid Rice Liangyoupeijiu FENG Yue-hua,ZOU Ying-bin,Roland J. BURESH 2011, 25(1): 65-70 .  DOI: 10.3969/j.issn.1001-7216.2011.01.010 Abstract ( )   PDF (511KB) ( )   To ascertain the effects of notillage and transplanting(NT) on some population characteristics of hybrid rice, a comparison experiment with the hybrid rice combination Liangyoupeijiu as material was conducted under the conditions of NT and conventionaltillage and transplanting (CT) in Changsha in 2004-2006. Compared with CT, NT displayed lower leaf area index and less photosynthetic potential and lower dry matter accumulation before and after heading and less total dry matter accumulation. The export and translocation percentage of the matter in stem and sheaths, the export percentage and export amount of the matter in stem and leaves under the conditions of NT were 141%, 177%, 0.7%, and 8.4% lower than those under CT, respectively, whereas the ratios of the number of spikelets to leaf area, the number of filled grains to leaf area and the grain weight to leaf area under NT were 118%, 77%, and 11.0%, respectively, higher than those under CT. The net assimilation rate under NT was lower than that under CT from the midtillering stage to panicle initiation stage, whereas the net assimilation rate under NT was 741% higher than that under CT from the panicle initiation stage to heading stage The single stemsheath weight under NT was lower than that under CT at the midtillering stage, whereas the single stemsheath weights under NT were 176% and 44% higher than that under CT at the panicle initiation and heading stages, respectively. Compared with CT, NT displayed lower effective panicle number, seed setting rate and productive tiller percentage， higher spikelet number per panicle, 1000grain weight and harvest index. The average yield under NT reached 89307 kg/hm2, with an increase of 102% compared with CT, however, the difference was not significant at 5% level between CT and NT.

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Effects of Nitrogen Application Rate on Ammonia Volatilization and Nitrogen Utilization in Rice Growing Season YE Shi-chao,＃,LIN Zhong-cheng,＃,DAI Qi-gen,JIA Yu-shu,GU Hai-yan,CHEN Jing-dou,XU Lu-sheng,WU Fu-guan,ZHANG Hong-cheng,HUO Zhong-yang,XU Ke,WEI Hai-yan 2011, 25(1): 71-78 .  DOI: 10.3969/j.issn.1001-7216.2011.01.011 Abstract ( )   PDF (2413KB) ( )   In contrast experiments in sandy soil and clay soil, effects of nitrogen application rates on the concentration of NH4+N in surface water, the loss of ammonia volatilization from paddy field, the production of rice, the nitrogen utilization efficiency and the nitrogen content in soil profile were studied. The concentration of NH4+N in surface water and the amount of ammonia volatilization losses all increased as the nitrogen application rate increased, and peaked at 13 days after nitrogen application. The loss of ammonia volatilization from clay soil was lower than that from sandy soil. The amounts of ammonia volatilization losses after nitrogen application at different stages were as follows: N application for promoting tillering > The first N topdressing for promoting panicle initiation(applied at the last 4thleaf stage) > basal fertilizer > The second N topdressing for promoting panicle initiation(applied at the last 2ndleaf stage). The total loss of ammonia volatilization from clay soil was 10.49-87.06 kg/hm2, accounting for 10.92%-21.76% of the nitrogen applied; the total loss of ammonia volatilization from sandy soil was 11.32-102.43 kg/hm2, occupying 11.32%-25.61% of the nitrogen applied. The amount of ammonia volatilization and the concentration of NH4+N in surface water reached their peaks at the same time after nitrogen application; the maximum appeared at the tillering stage with their ratios from 23.76% to 33.65%. With the increase of nitrogen application rate, rice production and the nitrogen accumulation in plants increased, but nitrogen use efficiency decreased. Rice production and the nitrogen accumulation in plants in clay soil were slightly higher than those in sandy soil. Soil nitrogen content in the depth of 4050 cm was the lowest; soil nitrogen content in the same layers increased with the increasing nitrogen application rate, and soil nitrogen content in clay soil was higher than that in sandy soil. From the view on ammonia volatilization, it is found that the amount of ammonia volatilization would increase quickly when the nitrogen application rate exceeded 250 kg/hm2 in rice growing season. However, from the view on rice production, the suitable nitrogen application rate should be about 300 kg/hm2. Therefore, considering highyield and environment protection, the appropriate nitrogen application rate was from 250 to 300 kg/hm2 in the condition of the experiment.

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Effects of RowSpacing on Yield of SuperHighYielding Early and Late Rice LIN Hong-xin,PAN Xiao-hua,SHI Qing-hua,PENG Chun-rui,WU Jian-fu,LEI Xiang-liang 2011, 25(1): 79-85 .  DOI: 10.3969/j.issn.1001-7216.2011.01.012 Abstract ( )   PDF (370KB) ( )   With the same planting density（3×105hills/hm2 for early rice and 2.5×105 hills/hm2 for late rice）, the effect of rowspacing on the yield of superhighyielding rice was studied at three nitrogen application levels with early rice Ganxin 203 and Luliangyou 996 and late rice Tianyouhuazhan and Ganxin 688 as materials. Narrow rowspacing was favorable for higher yield of the four tested materials with no nitrogen application. With the same nitrogen application levels, medium rowspacing produced higher yield for Ganxin 203, wide or narrow rowspacing for Luliangyou 996 and Tianyouhuazhan, and narrow rowspacing for Ganxin 688. Number of effective panicles was the main factor responsible for the effect of rowspacing on yield for both Luliangyou 996 and Tianyouhuazhan, but number of grains per panicle for Ganxin 203, and seedsetting rate for Ganxin 688. Different responses to rowspacing among different materials could be attributed to the number of grains per panicle and panicle forming rate, which were lower for Ganxin 203 and higher for Luliangyou 996 and Tianyouhuazhan, and to higher leaf area index for Ganxin 688. The appropriate rowspacing was 33.0 cm×10.0 cm or 20.6 cm×16.0 cm for early rice Luliangyou 996, 25.4 cm×13.0 cm for early rice Ganxin 203, 40.0 cm×10.0 cm or 20.0 cm×20.0 cm for late rice Tianyouhuazhan, and 20.0 cm×20.0 cm for late rice Ganxin 688.

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Comparison on Electrical Penetration Graph (EPG) of Two Populations of Nilaparvata lugens with Different Virulence PAN Jian-hong,CHEN Feng,HE Jia-chun,LAI Feng-Xiang,FU Qiang* 2011, 25(1): 86-90 .  DOI: 10.3969/j.issn.1001-7216.2011.01.013 Abstract ( )   PDF (905KB) ( )   The electrical penetration graph (EPG) of two populations of Nilaparvata lugens with different virulence（TN1 population, Mudgo population） on susceptible rice variety TN1 and resistant rice variety Mudgo (with resistance gene Bph1) were studied. The results showed that duration of I waveform significantly affected by population of N. lugens and rice variety, followed by A waveform, then S waveform. The sex of N. lugens did not affect the three types of waveform. Three virulent treatments (TN1 population on TN1, Mudgo population on TN1 and Mudgo) showed shorter S and A waveforms compared with nonvirulent treatment (TN1 population on Mudgo). And a significant difference in A waveform between virulent treatments and nonvirulent one was found. The I waveform under the three virulent treatments was significantly shorter than that under nonvirulent treatment. The accuracies to distinguish the virulence of TN1 population and Mudgo population were 82.6% and 100%, respectively with 75 min of I waveform in a 3h record period as a criterion(i.e., I waveform more than 75 min represented virulent, less than 75 min represented nonvirulent). It is suggested that the duration of I waveform is a possible alternative for monitoring the virulence of N. lugens individual.

实验技术

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A Simplified Method for Quick Detection of Rice BlackStreaked Dwarf Virus and Southern Rice BlackStreaked Dwarf Virus JI Ying-hua,GAO Rui-zhen,ZHANG Ye,CHENG Zhao-bang,ZHOU Tong,FAN Yong-jian,ZHOU Yi-jun 2011, 25(1): 91-94 .  DOI: 10.3969/j.issn.1001-7216.2011.01.014 Abstract ( )   PDF (887KB) ( )   Rice blackstreaked dwarf virus and southern rice blackstreaked dwarf virus are two important viruses in rice, which cause great losses in local rice production in recent years. The two viruses belong to Fijivirus. They share many similar characters, such as symptoms, virus particles, vectors, host range etc., causing difficulty in discrimination of the two viruses. Three degenerate primers were designed and a simple, rapid, efficient method was described.

研究简报

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Genetic Analysis and Fine Mapping of a GreenRevertible Albino Leaf Mutant in Rice GUO Shi-wei,WANG Yong-fei,MA San-mei,LI Xia,GAO Dong-ying 2011, 25(1): 95-98 .  DOI: 10.3969/j.issn.1001-7216.2011.01.015 Abstract ( )   PDF (483KB) ( )   A greenrevertible albino leaf mutant was found in an indica rice variety, Yixiang B, in the field. A stably inherited mutant with greenrevertible albino leaf was obtained after five successive generations of selfcrossing, and temporarily named as gra. The leaf color of gra was albino before 4th leaf stage, and then gradually turned green. As the content of chlorophyll in leaves increased from 4weekold to 12weekold seedlings, the ratio of mutant/wild chlorophyll content in rice leaves rose from 34.5% to 99.4%. Genetic analysis of F2 populations showed that the mutation was controlled by a single recessive nuclear gene. The gene was finely mapped between the SSR markers RM25522 and RM25535, with genetic distances of 0.05 cM to each marker, respectively, and a physical distance of 136 kb.

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Quantitative Trait Loci Associated with Pollen Fertility Under High Temperature Stress at Flowering Stage in Rice PAN Yi,LUO Li-hua,DENG Hua-bing,ZHANG Gui-lian,TANG Wen-bang,CHEN Li-yun,XIAO Ying-hui* 2011, 25(1): 99-102 .  DOI: 10.3969/j.issn.1001-7216.2011.01.01 Abstract ( )   PDF (631KB) ( )   The quantitative trait loci (QTLs) underlying tolerance to high temperature stress(HTS) were identified using the recombinant inbred lines (RILs) derived from a cross between the heat tolerant rice line 996 and the sensitive line 4628. Pollen fertility was used as the heattolerance indicator for the lines, which was determined when the lines was subjected to HTS at the flowering stage in field experiments. Two QTLs that affected pollen fertility were detected in the interval between RM5687 and RM471 on chromosome 4, and between RM190 and RM225 on chromosome 6 by using composite interval mapping (CIM) analysis. The QTL qPF4 on chromosome 4 explained 15.1% of the total variation in pollen fertility, and increased the pollen fertility of HTSsubjected plants by 7.15%. The second QTL qPF6 on chromosome 6 explained 9.31% of the total variation in pollen fertility, and increased the pollen fertility of plants subjected to HTS by 5.25%. The positive additive effects of the two QTLs were derived from the line 996 alleles. The two major QTLs identified should be useful for further fine mapping and cloning of these genes and for molecular markerassisted selection of heattolerant rice cultivars.

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Analysis on Correlationship of Net Photosynthetic Rate with Yield and Its Components of Ratooning Rice ZHANG Jian-fu ,ZHU Yong-sheng,CAI Qiu-hua,ZHUO Chuan-ying,ZHANG Shang-shou,ZHENG Rong-he ,XIE Hua-an 2011, 25(1): 103-106 .  DOI: 10.3969/j.issn.1001-7216.2011.01.017 Abstract ( )   PDF (356KB) ( )   The net photosynthetic rate of flag leaf was measured at the filling stage and maturity stage of ratooning rice with thirteen hybrid rice combinations as materials. The net photosynthetic rate at the filling stage of ratooning rice was significantly higher than that at the maturity stage, and the difference in the photosynthetic rate at the filling stage was more than that at the maturity stage among all the combinations, and the net photosynthetic rate was significantly different at the same stage among different combinations. The net photoynthetic rate at the filling stage was positively correlated with the yield of ratooning rice, and that at the maturity stage was significantly and negatively correlated with the yield of ratooning rice. In addition, the net photosynthetic rate at the filling stage was significantly and positively correlated with the seed setting rate.

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Pathotype Identification and Distribution of Xanthomonas oryzae pv. oryzae in Japonica Rice Planted Region of the Northwest Yunnan Plateau, China PENG Xin-xi,YU Teng-qiong,LI Jun,YANG Ya-yun,HE Jian-ping,LI Jin-ling ,XU Fu-rong,DAI Lu-yuan 2011, 25(1): 107-111 .  DOI: 10.3969/j.issn.1001-7216.2011.01.018 Abstract ( )   PDF (501KB) ( )   Thirty isolates of Xanthomonas oryzae pv. oryzae (Xoo) collected from japonica rice in the northwest Yunnan plateau including Chuxiong, Dali and Lijiang prefectures were tested on seven differential cultivars(Haonuoyang, TN1, Kogyoku, Zhenzhu’ai, IR26, Nanjing 33 and Kinmaze) to analyze their pathotypes and distributions. Nine pathotypes were identified, of which pathotype Ⅰ was dominant and pathotype Ⅴ was the most virulent. The isolate DL089 might be a new pathotype according to its disease reaction pattern (RRRRSSS) (R, resistant; S, susceptible) in the seven differential cultivars.

综述与专论

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Investigation on the Mechanism of Adaption of Plasma Membrane H+ATPase to Ammonium Nutrition in Rice ZHU Yi-yong,ZENG Hou-qing,DI Ting-jun,XU Guo-hua,SHEN Qi-rong* 2011, 25(1): 112-118 .  Abstract ( )   PDF (543KB) ( )   The preference of paddy rice for NH4+ rather than NO3- is associated with its tolerance to low pH since a rhizosphere acidification occurs during NH4+ absorption. However, the adaptation of rice root to low pH has not been fully elucidated. The plasma membrane H+ATPase is a universal electronic H+ pump, which uses ATP as energy source to pump H+ across plasma membranes into the apoplast. The key function of this enzyme is to keep pH homeostasis of plant cells and generate a H+ electrochemical gradient, thereby providing the driving force for the active influx and efflux of ions and metabolites across the plasma membrane. The acclimation of plasma membrane H+ ATPase of rice root to low pH may be partly responsible for the preference of rice plants to NH4+ nutrition.