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How to overcome yield stagnation is a big challenge to rice breeders. An effective method for quickly developing new cultivars is to further improve an outstanding cultivar. In this study, three advanced backcross populations under yield selection that consist of 123 BC2F2:4 introgression lines (ILs) were developed by crossing Minghui 86 (recurrent parent, RP) with three high-yielding varieties (donors), namely, ZDZ057, Fuhui 838, and Teqing, respectively. The progeny testing allowed the identification of 12 promising ILs that had significantly higher mean grain yields than Minghui 86 in two environments. A total of 55 QTLs that affect grain yield and its related traits were identified, which included 50 QTLs that were detected using the likelihood ratio test based on stepwise regression (RSTEP-LRT) method, and eight grain yield per plant (GY) QTLs were detected using chi-squared (c2) test. Among these QTLs, five QTLs were simultaneously detected in different populations and 22 QTLs were detected in both environments. The beneficial donor alleles for increased GY and its related traits were identified in 63.6% (35 out of 55) of the QTLs. These promising ILs and QTLs identified will provide the elite breeding materials and genetic information for further improvement of the grain yield for Minghui 86 through pyramiding breeding.

All members of the SnRK2 protein kinase gene family encoded by the rice (Oryza sativa L.) genome are activated by hyperosmotic stress, and have been designated as stress-activated protein kinases (SAPKs). In this study, gene structures, phylogeny, and conserved motifs for the entire OsSAPK gene family in rice have been analyzed. Moreover, expression patterns of OsSAPK in response to infection with Xanthomonas oryzae pv. oryzicola (Xoc) were investigated. A total of ten OsSAPK genes in the japonica rice cultivar 9804 were identified and classified into four groups. All genes had similar exon–intron structures and organization of putative motifs/domains, and shared the same four motifs (motifs 1–4). Group I (OsSAPK1 and OsSAPK2) shared another two motifs (motif 5 and motif 10), while group III (OsSAPK8, OsSAPK9 and OsSAPK10) had seven motifs in common (motifs 1–7). Moreover, we found that four OsSAPKs, including OsSAPK3, OsSAPK5, OsSAPK7 and OsSAPK9, were significantly upregulated in response to infection by Xoc in rice plants carrying the nonhost resistance gene Rxo1. Four of the OsSAPK genes in which expression was upregulated were localized to both the cytoplasm and nucleus, but clustered in different groups, suggesting that they are involved in different resistance signal transduction pathways. These results will provide useful information for the future functional dissection of this gene family.

Three populations with a total of 125 BC2F3:4 introgression lines (ILs) selected for high yields from three BC2F2 populations were used for genetic dissection of rice yield and its related traits. The progeny testing in replicated phenotyping across two environments and genotyping with 140 polymorphic simple sequence repeat markers allowed the identification of 21 promising ILs that had significantly higher yields than the recurrent parent Shuhui527 (SH527). A total of 94 quantitative trait loci (QTL) were identified using the selective introgression method based on Chi-squared (χ2) and multi-locus probability tests and the RSTEP-LRT method based on stepwise regression. These QTL were mostly mapped to 12 clusters on seven rice chromosomes. Several important properties of the QTL affecting grain yield (GY) and its related traits were revealed. The first one was the presence of strong and frequent non-random associations between or among QTL that affect low-heritability traits (GY and spikelet number per panicle, SN) in the ILs with high trait values. Second, beneficial alleles at 88.9 % GY and 75 % SN QTL for increased productivity were from the donors, suggesting that direct phenotypic selection for high yield in our introgression breeding program was a powerful way to transfer beneficial alleles at many loci from the donors into SH527. Third, most QTL were in clusters with large effects on multiple traits, which should be the focal points in further investigations and marker-assisted selection in rice. The majority of the QTL identified were expressed only in one of the environments, suggesting that differential expression of QTL in different environments is the primary genetic basis of genotype × environment interaction. Finally, a large variation in both the direction and magnitude of QTL effects was detected for different donor alleles at seven QTL in the same genetic background and environments. This finding suggests the possible presence of functional diversity among the donor alleles at these loci. The promising ILs and QTL identified provide valuable materials and genetic information for further improving the yield potential of SH527, which is a backbone restorer of hybrid rice in China.

Five new indole alkaloids, alocasins A-E (3-7), together with known hyrtiosin B (1) and hyrtiosulawesin (2) were isolated from Alocasia macrorrhiza (L.) SCHOTT; their structures were elucidated on the basis of spectroscopic data. Compounds 1-7 were in vitro tested for cytostatic activity on human throat cancer (Hep-2), human hepatocarcinoma (Hep-G2), and human nasopharyngeal carcinoma epithelial (CNE) cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method; compounds 2, 3, 6 and 7 showed mild antiproliferative activity against Hep-2 and Hep-G2 whereas compounds 2 and 4 showed gentle antiproliferative activity against CNE.

The genetic components responsible for the qualitative and quantitative resistance of rice to three Chinese races (C2, C4, and C5) of Xanthomonas oryzae pv. oryzae (Xoo) were investigated at the seedling and adult stages in two successive years in set of Lemont/Teqing cross introgression lines (ILs) in a Teqing background, to create a complete linkage map using 160 well-distributed SSR markers. Teqing was resistant to C2 and C4, but moderately susceptible to C5, whereas Lemont was susceptible to all three races. Highly significant correlations were detected among the resistance to different races at different developmental stages. A major gene (Xa4), 14 main-effect QTLs (M-QTLs), and 18 epistatic QTLs were identified in the two developmental stages over 2 years, and were largely responsible for the segregation of resistance in the ILs. In 2007, the Lemont alleles at all loci in the seedling stage, except QBbr10 to C4, increased lesion length (LL) or decreased resistance. The Teqing allele at the Xa4 locus acted as a resistance gene against C2 and C4, but acted as a M-QTL when its resistance was overcome by the virulent race C5. M-QTLs showed a degree of race specificity and had a cumulative effect on resistance. Most M-QTLs (94%) consistently expressed resistance to the same race at the seedling and adult stages, indicating that a high degree of genetic overlap exists between Xoo resistance at both developmental stages in rice. Among the digenic interactions, most co-introgressed Lemont alleles at the two epistatic loci lead to significantly smaller LL with all three races, compared to other types of interacting alleles at both development stages. The results indicate that a high level of resistance may be achieved by the cumulative effect of multiple M-QTLs, including the residual effects of “defeated” major resistance genes and the epistatic effects of co-introgression from diverse susceptible varieties.

Rice black-streaked dwarf virus (RBSDV) and stripe virus (RSV) are the two chronic viral diseases causing great damage to rice (Oryza sativa L.) production in China, and both are transmitted by the small brown planthopper (SBPH, Laodelphaxstriatellus Fallen). Quantitative trait loci (QTL) affecting field resistance to these two viral diseases were identified using QTL mapping software in a set of reciprocal introgression lines derived from the cross between Lemont and Teqing. A panel of 119 landraces was used for marker confirmation and allele mining. A total of 17 quantitative resistance loci (QRL) for the infection incidences of RBSDV and RSV were discovered and belong to 16 regions on all chromosomes except chromosome 12. Among them, 12 QRL were confirmed by association mapping, and many novel alleles at these loci were mined from the set of landraces. Only one region was found to be responsible for the genetic overlap between the field resistance against RBSDV and RSV, which was reported to be associated with SBPH resistance. The favorable alleles at the above novel and/or overlapping loci should be effective for marker-assisted selection breeding for resistance against the two diseases and the insect. Different strategies of varietal development and effective deployment against the two viral diseases are also discussed.

Perenniality is one of the important topics in rice breeding which is generally accompanied by complex physiobiochemical processes. To understand the metabolic characteristics of perennial rice, in the present study, gas chromatography–mass spectrometry and enzyme-linked immunosorbent assays were used to profile the distribution patterns of 33 primary metabolites and hormones [indole-3-acetic acid (IAA) and zeatin riboside (ZR)] of annual (RD23) and perennial (Oryza longistaminata and the line AA with RD23 genetic background) rice genotypes. Results showed that both metabolites and hormones have distinct genotype and organ distribution patterns, and considerable variations were observed between the metabolites in stem bases of perennial and annual rice. Most of the metabolites, including sugars, organic acids, and amino acids, significantly accumulated in the stem bases of perennial rice by decreasing the level in roots and leaves. Fifteen metabolites consistently accumulated significantly in the stem bases of both perennial genotypes. Additionally, the organ-level IAA content and IAA/ZR ratio in the two perennials were considerably higher than those in RD23. The present study indicated that the significant accumulation of the metabolites at stem base and the higher IAA/ZR ratio are involved in the regulatory metabolism for rhizome development.

DNA methylation, one of the most important epigenetic phenomena, plays a vital role in tuning gene expression during plant development as well as in response to environmental stimuli. In the present study, a methylation-sensitive amplified polymorphism (MSAP) analysis was performed to profile DNA methylation changes in two contrasting rice genotypes under salt stress. Consistent with visibly different phenotypes in response to salt stress, epigenetic markers classified as stable inter-cultivar DNA methylation differences were determined between salt-tolerant FL478 and salt-sensitive IR29. In addition, most tissue-specific DNA methylation loci were conserved, while many of the growth stage-dependent DNA methylation loci were dynamic between the two genotypes. Strikingly, salt stress induced a decrease in DNA methylation specifically in roots at the seedling stage that was more profound in IR29 than in the FL478. This result may indicate that demethylation of genes is an active epigenetic response to salt stress in roots at the seedling stage, and helps to further elucidate the implications of DNA methylation in crop growth and development.

A novel bacterial blight (BB) resistance gene, Xa23 , identified from Oryza rufipogon was introgressed into three popular restorer lines (Minghui63, YR293 and Y1671) for wild abortive cytoplasmic male sterility by marker-assisted backcross breeding approach in combination with artificial inoculation and stringent phenotypic selections. The three derived BB resistant restorer lines (Minghui63– Xa23 , YR293– Xa23 and Y1671– Xa23 ) and their hybrid combinations with Zhenshan97A (Shanyou63– Xa23 ), NongfengA (Fengyou293– Xa23 ) and Zhong9A (Zhongyou1671– Xa23 ) demonstrated similar BB resistance spectrum as the donor parent, CBB23 (B). The newly developed BB resistant restorers and their derived hybrids were identical to their respective original versions for agronomic traits especially under disease free condition. However, under severe disease condition, the three BB resistant restorer lines exhibited significantly higher grain weight and spikelet fertility as compared to the respective original restorer lines thus further resulting in BB resistant hybrids with significantly higher grain yields than their respective popular original hybrids. The results indicated that the Xa23 gene could completely express its dominant broad spectrum resistance in different backgrounds of both restorer and male sterile lines across different growth stages, suggesting its immense breeding value in BB resistance improvement for hybrid rice. Moreover, a reasonable utilization and deployment of Xa23 gene for efficient control of BB disease in hybrid rice production was recommended.

The present study was carried out to illustrate high-efficient detection of quantitative trait loci (QTLs) with selected introgression lines (ILs) and the existence of ‘hidden genes’ conferring drought tolerance (DT). 52 selected DT ILs, derived from BC 2 F 2 population developed by crossing and backcrossing the susceptible recurrent parent (RP) IR64 with the susceptible donor Khazar were planted under irrigation and drought condition. Four important agronomic traits, e.g., grain yield (GY), heading date (HD), panicle numbers per plant (PN), and plant height (PH) were evaluated and 83 SSR polymorphic molecular markers were used for genotypic analysis. Chi-square test based on genetic hitch-hiking and one-way analysis of variances (ANOVA) were used to detect drought-related loci. Nine and 36 loci were detected by chi-square test and one-way ANOVA, respectively. Five common loci were observed by comparing the results of the two methods, among which two QTLs linked with RM7, and RM241 were detected under irrigation condition, both of the favorable alleles were from RP and explained 13% phenotypic variation (PV) for GY and 28% PV for PH, respectively. The other three QTLs linked with RM163, RM18, and RM270 were detected under drought condition, the favorable alleles were all from the donor and explained 10, 24, and 19% PV for HD, PH, and PH, respectively. Five common loci were observed by comparing the results of chi-square test and one-way ANOVA including two QTLs (one for GY and one for PH) under irrigation condition and three QTLs (one for HD and two for PH) under drought condition. By combining phenotypic and genotypic analysis, drought escape could be inferred as the main mechanism for drought tolerance in the present study. The results in present study suggested that the selected ILs population analyzed by chi-square test and one-way ANOVA was quite effective for DT QTL detection with low inputs and could also produce useful materials for breeding with wide genetic diversity for drought tolerance.

Iron is an important micro-nutrient to human health. Malnutrition of iron is a serious problem associated with resource poor population in many developing countries. Development and consumption of iron-rich rice (Oryza sativa L.) varieties are considered one of the ways to solve this problem. To facilitate large-scale screening of breeding materials for iron concentration in the rice iron-biofortified breeding program of China, a new method “surging and grind-milling of orthophenanthroline colorimetry testing (SGOC)” was developed. Based on the testing results of 3 sets of 84 diverse rice genotypes that differ greatly in grain iron concentration, the correlation coefficient was as high as 0.87 between the SGOC method and the standard ICP-MS testing method. The per sample cost of the SGOC method was about 0.1 US dollar or 50 times less the ICP-MS method, indicating that the SGOC method is robust, fast, and cost-effective, particularly useful for preliminary screening of the iron concentration of large numbers of early generation breeding materials. The iron concentration of processed rice that tended to be significantly increased when milling and polishing with iron-made equipment was also eliminated in the SGOC method. Based on the analysis of iron concentration in 59 backcross progenies, the introgression of genes/quantitative trait loci for high iron concentration from high iron rice germplasm into elite local rice varieties is an efficient way to develop high yielding rice varieties with significantly improved rice iron concentration in future rice biofortified breeding.

The objectives of this study were to gain insight into the temporal and spatial expression patterns of two-component system (TCS) genes in rice (Oryza sativa L.) under drought stress and to understand the relationship between TCS gene expression and drought resistance. Using a whole rice genome microarray, the expression profiles of TCS genes of rice lines with different drought resistance were analyzed at various growth stages. The TCS genes showed greatly difference of expression pattern in various organs but in similar patterns in the same tissues at different stages. Genes for type-A response regulator (RR), a negative regulator of cytokinin (CK) signaling, were mostly repressed by drought stress, whereas, genes for type-B RR with an opposite role to type-A RR were mostly induced by drought stress. These changes were supposed to be related to the enhancement of CK signaling under drought stress. This supposition was confirmed by the down regulation of ethylene receptor genes and the cross-talk of hormones under drought condition. The His kinase genes (HK5 and HK3) that are homologous to CK receptor genes (AHK2, AHK3, and CRE1) in Arabidopsis were induced by drought stress. However, HK6 homologous to AHK5 (CK-independent 2, CKI2) was repressed when exposed to drought stress. These results provided further confirmations of the above supposition. In drought resistant introgression lines and IR64, no significant differences of TCS gene expression profiles were observed under drought stress. This result indicates that the TCS genes are probably in relation to drought responsiveness.

Expression of quantitative trait locus (QTL) is affected by genetic background (GB) and environment. The GB effect on QTL mapping and QTL by environment interaction for heading date (HD) and plant height (PH) were studied in Beijing and Hainan environments using a large set of reciprocal introgression lines (ILs) derived from a japonica rice (Oryza sativa L.) variety Lemont and an indica variety Teqing. In both environments, the 2 IL populations showed transgressive segregation for HD and PH traits. A total of 16 and 17 main-effect QTLs (M-QTLs) were identified for HD and PH, respectively. Among them, only 5 M-QTLs were detected under the 2 GBs, indicating that the expressions of most M-QTLs are specific to GB. Under both GBs, significant interactions between QTLs and environment responsible for HD were observed at 3 M-QTLs, of which QHd8a antedated heading for 2–3 d in Hainan but delayed heading for 2–3 d in Beijing. Therefore, QHd8a could be considered as an important M-QTL for HD. By comparing with the previous results on QTL mapping using another 7 populations derived from the same parents, a few M-QTLs were found to express stably under different GBs in various environments, such as QHd3, QHd8a, QPh3, and QPh4. These QTLs show applicable potential in marker-assisted breeding for HD and PH in rice.

Rice bacterial leaf blight (BB) caused by Xanthomonasoryzae pv. oryzae and bacterial leaf streak (BLS) caused by X. oryzae pv. oryzicola (Xoc) are two important diseases of rice that often outbreak simultaneously and constrain rice production in much of Asia and parts of Africa. Developing resistant cultivars has been the most effective approach to control BB, however, most single resistance genes have limited value in breeding programs because of their narrow-spectrum of resistance to the races of the pathogen. By contrast, there is little progress in breeding varieties resistant to Xoc since BLS resistance in rice was a quantitative trait and so far only a few quantitative resistance loci have been identified. We reported here the development of a high yield elite line, Lu-You-Zhan highly resistant to both BB and BLS by pyramiding Xa23 with a wide-spectrum resistance to BB derived from wild rice and a non-host maize resistance gene, Rxo1, using both marker assisted selection (MAS) and genetic engineering. Our study has provided strong evidence that non-host R genes could be a valuable source of resistance in combating those plant diseases where no single R gene controlling high level of resistance exists and demonstrated that MAS combined with transgenic technologies are an effective strategy to achieve high level of resistance against multiple plant diseases.

To detect quantitative trait loci (QTLs) for resistance to rice sheath blight (SB) that expressed stably in different genetic backgrounds and environments, the reciprocal introgression line populations derived from the cross of Lemont and Teqing (LT-ILs and TQ-ILs) were planted in the field in 2006–2007 and inoculated with isolate RH-9 of Rhizoctonia solani . Lemont was highly susceptible, whereas Teqing was moderately resistant to RH-9. The relative lesion height (a ratio of lesion height to plant height) of TQ-ILs was normally distributed, whereas that of LT-ILs was apparently inclined to the susceptible parent Lemont. A total of 10 main-effect QTLs (M-QTLs) and 13 epistatic QTLs (E-QTLs) conferring sheath blight resistance (SBR) were mapped using data obtained from different years and genetic backgrounds. Among them, 6 M-QTLs detected in 2006 were verified in 2007, suggesting that these M-QTLs had reliable performance across years. QRlh4 was the only M-QTL expressed under the reciprocal backgrounds. On chromosome 10, QRlh10a between RM216 and RM311 detected in TQ-ILs and QRlh10b between RM222 and RM216 detected in LT-ILs were regarded as different genes because their directions of additive effect were opposite. Most QTLs identified in TQ-ILs were not expressed in LT-ILs, indicating the presence of a significant effect of genetic background. By comparative mapping, 8 M-QTLs detected in this study were located in the same or near regions that were associated with SBR identified in the previous studies. These M-QTLs have great potential to be applied in rice breeding for SBR by marker-assisted selection (MAS), and M-QTLs expressed stably in different backgrounds are favorable for gene pyramiding in SBR improvement in rice.

QTLs for salt-tolerance (ST) related traits at the seedling and tillering stages were identified using 99 BC(2)F(8) introgression lines (IL) derived from a cross between IR64 (indica) as a recurrent parent and Binam (japonica) from Iran as the donor parent. Thirteen QTLs affecting survival days of seedlings (SDS), score of salt toxicity of leaves (SST), shoot K(+) concentration (SKC) and shoot Na(+) concentration (SNC) at the seedling stage and 22 QTLs underlying fresh weight of shoots (FW), tiller number per plant (TN) and plant height (PH) at the tillering stage were identified. Most QTLs detected at the tillering stage showed obvious differential expression to salt stress and were classified into three types based on their differential behaviors. Type I included 11 QTLs which were expressed only under the non-stress condition. Type II included five QTLs expressed in the control and the salt stress conditions, and three of them (QPh5, QPh8 and QTn9) had similar quantity and the same direction of gene effect, suggesting their expression was less influenced by salt stress. Type III included six QTLs which were detectable only under salt stress, suggesting that these QTLs were apparently induced by the stress. Thirteen QTLs affecting trait difference or trait stability of ILs between the stress and non-stress conditions were identified and the Binam alleles at all loci except QPh4, QTn2 and QFw2a decreased trait difference. The three QTLs less influenced by the stress and 13 QTLs affecting trait stability were considered as ST QTLs which contributed to ST. Comparing the distribution of QTLs detected at the seedling and tillering stages, most (69%) of them were genetically independent. Only four were the same or adjacent regions on chromosomes 1, 2, 8 and 11 harboring ST QTLs detected at the two stages, suggesting that partial genetic overlap of ST across the two stages occurs. It is likely, therefore, to develop ST rice variety for both stages by pyramiding of ST QTLs of different stages or selection against the overlapping QTLs between the two stages via marker-assisted selection (MAS).

Plant photosynthetic traits such as net photosynthetic rate (Pn), stomata conductance (gs), transpiration rate (Tr), and intercellular CO2 concentration (Ci), are known to relate to drought tolerance in plants, but the genetic basis of these traits remains largely uncharacterized because of the difficulty in phenotyping physiological traits in a large mapping population. In this study, a set of 55 overlapping introgression lines (ILs) in the Teqing (indica) background were used to genetically dissect several morph-physiological traits and their relationship with grain yield under water stress and non-stress conditions. These traits included specific leaf weight (SLW), chlorophyll content (CC), leaf stomata frequency (SF), Pn, gs, Tr, and Ci. A total of 40 QTLs affecting the measured traits were identified and mapped to 21 genomic regions in the rice genome. Clustered QTLs affecting Pn, gs, Tr, and Ci in the same genomic regions suggest common genetic bases for the physiological traits. Low or no phenotypic correlations between leaf morphological traits and photosynthetic traits and between morph-physiological traits and grain yield (GY) appeared to be due to inconsistence in QTL effect for clustered QTLs, unlinked QTLs affecting different traits, and to possible epistasis that could not be adequately addressed in this study. Our results indicate that improving drought tolerant (DT) of rice by selecting any single secondary traits is not expected to be effective and the identified QTLs for GY and related morph-physiological traits should be carefully confirmed before to be used for improving DT in rice by MAS.

Drought tolerance (DT) in rice is known to be controlled by many quantitative trait loci (QTLs) and involved differential expression of large numbers of genes, but linking QTLs with their underlying genes remains the most challenging issue in plant molecular biology. To shed some light on this issue, differential gene expression in response to PEG simulated drought in 3 unique genetic materials (a lowland rice, IR64 and its derived line, PD86 which has 11 introgressed DT QTLs, and a upland rice IRAT109) was investigated using a PCR-based subtractive hybridization strategy. More than 300 unique subtracted cDNA sequences, covering genes of diverse cellular activities and functions, were identified and confirmed by semi-quantitative and quantitative RT-PCR. Detailed bioinformatics analyses of the data revealed two interesting results. First, the levels and mechanisms of DT of the three rice lines were associated with the number and types of differentially expressed genes, suggesting different DT mechanisms in rice are controlled by different sets of genes and different metabolic pathways, and most differentially expressed genes under drought were able to contribute to DT. Second, there appeared a high correspondence in genomic location between DT QTLs and clusters of differentially expressed genes in rice, suggesting some DT QTLs may represent clusters of co-regulated and functionally related genes. Thus, differential gene expression analyses using genetically characterized materials can provide additional insights into the molecular basis of QTLs and convergent evidence to shortlist the candidate genes for target QTLs.

Cell death in the roots of two rice ecotypes under PEG-induced osmotic and NaCl stresses were assayed by TUNEL and DAPI techniques. Although both ecotypes exhibited cell death in response to the osmotic and salt stresses, they appeared to adapt to the two types of stresses through different timing and tissue specificity of cell death. Under the stresses, the occurrence of cell death was always delayed in IRAT109, a drought tolerant upland line, than in IR20, a drought sensitive lowland line. Under the salt stress, cell death progressed successively in a well regulated manner, starting from the outer layer cells in the epidermis and exodermis of roots and subsequently to the endodermis and stele, suggesting a possible function of the dead cells in preventing the influx of excess Na+ ions into the inner parts of roots and into shoots, leading to salt exclusion. In contrast, cell death induced by PEG-induced osmotic stress occurred randomly in roots, allowing a better ability to recover after stress. Thus, the coincidence of the difference in drought tolerance between the two rice ecotypes and their differences in the osmotic/salt induced cell death indicate that cell death may have played an important role contributing to rice tolerances to different abiotic stresses.

Tremendous efforts have been taken worldwide to develop genome-wide genetic stocks for rice functional genomic (FG) research since the rice genome was completely sequenced. To facilitate FG research of complex polygenic phenotypes in rice, we report the development of over 20,000 introgression lines (ILs) in three elite rice genetic backgrounds for a wide range of complex traits, including resistances/tolerances to many biotic and abiotic stresses, morpho-agronomic traits, physiological traits, etc., by selective introgression. ILs within each genetic background are phenotypically similar to their recurrent parent but each carries one or a few traits introgressed from a known donor. Together, these ILs contain a significant portion of loci affecting the selected complex phenotypes at which allelic diversity exists in the primary gene pool of rice. A forward genetics strategy was proposed and demonstrated with examples on how to use these ILs for large-scale FG research. Complementary to the genome-wide insertional mutants, these ILs opens a new way for highly efficient discovery, candidate gene identification and cloning of important QTLs for specific phenotypes based on convergent evidence from QTL position, expression profiling, functional and molecular diversity analyses of candidate genes, highlights the importance of genetic networks underlying complex phenotypes in rice that may ultimately lead to more complete understanding of the genetic and molecular bases of quantitative trait variation in rice.

To explore the effects of gender on treatment strategies for elderly patients with acute coronary syndrome (ACS).March 2009 to March 2012, consecutive 619 aged ACS patients undergoing coronary angiography (CA) were screened at our hospital. There were 273 females and 346 males. Risk factors, ACS diagnosis, CA results, treatments and prognosis were compared between female and male groups.The risk factors of body mass index, stroke history, smoking history, hemoglobin (Hb), serum cholesterol (TC), low density lipoprotein (LDL-C) and blood uric acid (UA) levels were significantly lower in female group than those in male group (P0.05). The morbidity of diabetes in female group was obviously higher than that in male group (27.8% vs 18.5%, P0.05). The prevalence of myocardial infarction history, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) history in male group were significantly greater than that in female group (48.0% vs 39.9%, P0.05; 30.6% vs 22.3%, P0.05; 19.9% vs 10.3%, P0.01). The rate of combined multiple risk factors (3 or higher) increased significantly in female group (41.8% vs 29.8%, P0.05). The incidence of unstable angina pectoris (UAP) and non-ST segment elevation myocardial infarction (NSTEMI) in female group was greater, but there was no statistical significance. The rate of 3-vessel and calcification lesions in female group was significantly elevated compared with male group (36.26% vs 28.61%, P0.05). Regarding the choice of treatment strategy, conservative treatment was common in females, but there was no statistical significance between them. PCI, emergency PCI and selective CABG operation were performed more frequently in female group compared with male group (26.0% vs 14.2%, P0.01; 14.7% vs 6.6%, P0.01; 19.1% vs 7.7%, P0.01). The prognosis had no statistical significance between two groups.The treatment strategies have certain limitations for female ACS patients. And an more aggressive treatment should be offered to improve the prognosis.

Desmoid tumors (DTs) are nonmetastatic, locally aggressive neoplasms with a high rate of postoperative recurrence. Pancreatic DTs are especially rare; only a few cases have been reported to date. This paper describes a case of a sporadic cystic DT of the pancreas managed successfully with central pancreatectomy, with no signs of recurrence 40 mo after surgery. According to the literature, this is the first reported case in China of a pancreatic DT presenting as a solid cystic lesion, as well as the first pancreatic DT managed with central pancreatectomy and pancreaticogastrostomy. We report the case for its rarity and emphasize disease management by concerted application of clinical, pathological, radiological and immunohistochemical analyses.

Transcriptomic data for Sorghum propinquum, the wild-type sorghum, are limited in public databases. S. propinquum has a subterranean rhizome and transcriptome data will help in understanding the molecular mechanisms underlying rhizome formation. We sequenced the transcriptome of S. propinquum aerial-shoot and rhizome using an Illumina platform. More than 70 % of the genes in the S. propinquum genome were expressed in aerial-shoot and rhizome. The expression patterns of 1963 and 599 genes, including transcription factors, were specific or enriched in aerial-shoot and rhizome respectively, indicating their possible roles in physiological processes in these tissues. Comparative analysis revealed several cis-elements, ACGT box, GCCAC, GATC and TGACG box, which showed significantly higher abundance in aerial-shoot-specific genes. In rhizome-specific genes MYB and ROOTMOTIFTAPOX1 motifs, and 10 promoter and cytokinin-responsive elements were highly enriched. Of the S. propinquum genes, 27.9 % were identified as alternatively spliced and about 60 % of the alternative splicing (AS) events were tissue-specific, suggesting that AS played a crucial role in determining tissue-specific cellular function. The transcriptome data, especially the co-localized rhizome-enriched expressed transcripts that mapped to the publicly available rhizome-related quantitative trait loci, will contribute to gene discovery in S. propinquum and to functional studies of the sorghum genome. Deep transcriptome sequencing revealed a clear difference in the expression patterns of genes between aerial-shoot and rhizome in S. propinquum. This data set provides essential information for future studies into the molecular genetic mechanisms involved in rhizome formation.

Sorghum (Sorghum bicolor) is one of the world's most important cereal crops. S. propinquum is a perennial wild relative of S. bicolor with well-developed rhizomes. Functional genomics analysis of S. propinquum, especially with respect to molecular mechanisms related to rhizome growth and development, can contribute to the development of more sustainable grain, forage, and bioenergy cropping systems. In this study, we used a whole rice genome oligonucleotide microarray to obtain tissue-specific gene expression profiles of S. propinquum with special emphasis on rhizome development. A total of 548 tissue-enriched genes were detected, including 31 and 114 unique genes that were expressed predominantly in the rhizome tips (RT) and internodes (RI), respectively. Further GO analysis indicated that the functions of these tissue-enriched genes corresponded to their characteristic biological processes. A few distinct cis-elements, including ABA-responsive RY repeat CATGCA, sugar-repressive TTATCC, and GA-responsive TAACAA, were found to be prevalent in RT-enriched genes, implying an important role in rhizome growth and development. Comprehensive comparative analysis of these rhizome-enriched genes and rhizome-specific genes previously identified in Oryza longistaminata and S. propinquum indicated that phytohormones, including ABA, GA, and SA, are key regulators of gene expression during rhizome development. Co-localization of rhizome-enriched genes with rhizome-related QTLs in rice and sorghum generated functional candidates for future cloning of genes associated with rhizome growth and development.

Background Rice in tropical and sub-tropical areas is often subjected to cold stress at the seedling stage, resulting in poor growth and yield loss. Although japonica rice is generally more cold tolerant (CT) than indica rice, there are several favorable alleles for CT exist in indica that can be used to enhance CT in rice with a japonica background. Genome-wide gene expression profiling is an efficient way to decipher the molecular genetic mechanisms of CT enhancement and to provide valuable information for CT improvement in rice molecular breeding. In this study, the transcriptome of the CT introgression line (IL) K354 and its recurrent parent C418 under cold stress were comparatively analyzed to explore the possible CT enhancement mechanisms of K354. Results A total of 3184 differentially expressed genes (DEGs), including 195 transcription factors, were identified in both lines under cold stress. About half of these DEGs were commonly regulated and involved in major cold responsive pathways associated with OsDREB1 and OsMyb4 regulons. K354-specific cold-induced genes were functionally related to stimulus response, cellular cell wall organization, and microtubule-based movement processes that may contribute to increase CT. A set of genes encoding membrane fluidity and defensive proteins were highly enriched only in K354, suggesting that they contribute to the inherent CT of K354. Candidate gene prediction based on introgressed regions in K354 revealed genotype-dependent CT enhancement mechanisms, associated with Sir2, OsFAD7, OsWAK112d, and programmed cell death (PCD) related genes, present in CT IL K354 but absent in its recurrent parent C418. In K354, a number of DEGs were co-localized onto introgressed segments associated with CT QTLs, providing a basis for gene cloning and elucidation of molecular mechanisms responsible for CT in rice. Conclusions Genome-wide gene expression analysis revealed that genotype-specific cold induced genes and genes with higher basal expression in the CT genotype contribute jointly to CT improvement. The molecular genetic pathways of cold stress tolerance uncovered in this study, as well as the DEGs co-localized with CT-related QTLs, will serve as useful resources for further functional dissection of the molecular mechanisms of cold stress response in rice.

Alocasin A (I), B (IIa), C (IIb), D (IIc) and alocasin E (III) are isolated together with known compounds hyrtiosin B and hyrtiosulawesin.

Five new indole alkaloids, alocasins A-E (3-7), together with known hyrtiosin B (1) and hyrtiosulawesin (2) were isolated from Alocasia macrorrhiza (L.) SCHOTT; their structures were elucidated on the basis of spectroscopic data. Compounds 1-7 were in vitro tested for cytostatic activity on human throat cancer (Hep-2), human hepatocarcinoma (Hep-G2), and human nasopharyngeal carcinoma epithelial (CNE) cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method; compounds 2, 3, 6 and 7 showed mild antiproliferative activity against Hep-2 and Hep-G2 whereas compounds 2 and 4 showed gentle antiproliferative activity against CNE.

To design and construct miRNA expression vector dual-targeting on HIF-1α and survivin genes and to investigate its effects on proliferation of human pancreatic cancer cells.The specific pre-miRNA single strand DNA oligos for HIF-1 α and survivin genes were designed and synthesized, then via annealing and ligating with pcDNA6.2-GW/EmGFP-miR plasmids in order, two kinds (eight in total) of miRNA expression vectors for HIF-1α and survivin genes were constructed. The vectors, which were most effective to knockdown target genes, were screened with real-time RT-PCR and combined by chaining technology to construct dual-targeting plasmid. The recombined dual-targeting plasmid, mono-targeting plasmids and negative plasmid were transfected into Panc-1 cells, the suppression effect on two genes was identified by real-time RT-PCR, Western blot and MTT assays.The miRNA expression plasmids anti-H, anti-S and anti-H+S were successfully constructed by identification of sequencing analysis, and they were able to effectively inhibit the target genes expressing. MTT assays showed that the inhibition effect of dual-targeting vector anti-H+S was higher than that of mono-targeting vectors anti-H and anti-S 72 h after transfection (P0.05).The effective miRNA expression vector dual-targeting on HIF-1α and survivin genes has been successfully constructed. The inhibition effect on proliferation of pancreatic cancer Panc-1 cells by dual-targeting plasmid was higher than that by mono-target plasmids.

Rice is sensitive to chilling stress, especially at the seedling stage. To elucidate the molecular genetic mechanisms of chilling tolerance in rice, comprehensive gene expressions of two rice genotypes (chilling-tolerant LTH and chilling-sensitive IR29) with contrasting responses to chilling stress were comparatively analyzed. Results revealed a differential constitutive gene expression prior to stress and distinct global transcription reprogramming between the two rice genotypes under time-series chilling stress and subsequent recovery conditions. A set of genes with higher basal expression were identified in chilling-tolerant LTH compared with chilling-sensitive IR29, indicating their possible role in intrinsic tolerance to chilling stress. Under chilling stress, the major effect on gene expression was up-regulation in the chilling- tolerant genotype and strong repression in chilling-sensitive genotype. Early responses to chilling stress in both genotypes featured commonly up-regulated genes related to transcription regulation and signal transduction, while functional categories for late phase chilling regulated genes were diverse with a wide range of functional adaptations to continuous stress. Following the cessation of chilling treatments, there was quick and efficient reversion of gene expression in the chilling-tolerant genotype, while the chilling-sensitive genotype displayed considerably slower recovering capacity at the transcriptional level. In addition, the detection of differentially-regulated TF genes and enriched cis-elements demonstrated that multiple regulatory pathways, including CBF and MYBS3 regulons, were involved in chilling stress tolerance. A number of the chilling-regulated genes identified in this study were co-localized onto previously fine-mapped cold-tolerance-related QTLs, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for chilling tolerance in rice.

Effect of genetic background on detection of quantitative trait locus (QTL) governing salinity tolerance (ST) was studied using two sets of reciprocal introgression lines (ILs) derived from a cross between a moderately salinity tolerant japonica variety, Xiushui09 from China, and a drought tolerant but salinity susceptible indica breeding line, IR2061–520–6-9 from the Philippines. Salt toxicity symptoms (SST) on leaves, days to seedling survival (DSS), and sodium and potassium uptake by shoots were measured under salinity stress of 140 mmol/L of NaCl. A total of 47 QTLs, including 26 main-effect QTLs (M-QTLs) and 21 epistatic QTLs (E-QTLs), were identified from the two sets of reciprocal ILs. Among the 26 M-QTLs, only four (15.4%) were shared in the reciprocal backgrounds while no shared E-QTLs were detected, indicating that ST QTLs, especially E-QTLs, were very specific to the genetic background. Further, 78.6% of the M-QTLs for SST and DSS identified in the reciprocal ILs were also detected in the recombinant inbred lines (RILs) from the same cross, which clearly brings out the background effect on ST QTL detection and its utilization in ST breeding. The detection of ILs with various levels of pyramiding of nonallelic M-QTL alleles for ST from Xiushui09 into IR2061-520-6-9 allowed us to further improve the ST in rice.

To study the feasibility of binding pancreatic duct to mucosa anastomosis (BDM)-a complementary procedure to both binding pancreaticojejunostomy and binding pancreaticogastrostomy.(1) Animal experimental study:gastrostomy and jejunostomy were performed on six adult New Zealand rabbits. The gastrostomy and jejunostomy shared a same stent (rubber urethral catheter, silicone tube or plastic infusion tube). Both ends of the stent were placed in gastric and enteric cavity. Purse-string suture was performed around the stent before the jejunum and the stomach were brought together for fixation by few stitches. And to observe whether the purse-string suture around a plastic tube, rubber tube or silicon tube inserted into jejunum and/or stomach can prevent leaking out of the jejunal or gastric content to cause peritonitis. (2) Clinically 7 patients were performed with BDM anastomosis. The procedure was consisted of five steps: preparation of the pancreatic stump;preparation of the jejunum; preparation of the fixing sutures between the pancreatic stump and the jejunum; implementation of the anastomosis; lastly, fixation of the jejunum beside the pancreas stump. Post-operative periodic examination of the blood amylase and the amylase in the abdominal drainage. Pancreatic fistula was classified in to two categories: parenchymal fistula (pancreatic cut surface fistula) and anastomotic leakage.Animal experiment did not show any leakage around the plastic tube or silicon tube inserted into jejunum and(or) stomach. There was no anastomotic leak in all the patients. There was transient increase of amylase in two cases, but the volume of drainage did not exceed 50 ml/d and the recovery of the patients was not affected.BDM is a simple, safe and easy procedure to perform. It provides to the surgeons with a new option in different situations to achieve the most ideal surgical result.

It is difficult and time-consuming for carrying out conventional hand-sewn bilioenteric anastomosis, especially for small bile duct anastomosis and laparoscopic procedure. In order to simplify it, we have developed a novel procedure of sutureless bilioenteric anastomosis with an intraluminal degradable stent. This study aimed to evaluate the feasibility and safety of this technique with cholangioduodenostomy in dog model.A patent intraluminal degradable stent tube for sutureless choledochoduodenostomy in dog model was made with polylactic acid in diameter of 3 mm or 4 mm. Thirty-eight dogs were randomly divided into to a stent group (SG, n = 20) and a control group (CG, n = 18). Dogs in the SG underwent sutureless choledochoduodenostomy with intraluminal stent, while the CG underwent conventional choledochoduodenostomy (single layer discontinuous anastomosis with absorbable suture). Dogs of each group were divided into 4 subgroups according to time of death (1, 3, 6, and 12 months postoperatively) to evaluate the healing of anastomosis. Operation time, intraoperative tolerance pressure of anastomosis, rate of postoperative bile leakage, bursting pressure of anastomosis were compared between the two groups. Anastomosis tissue was observed afterwards by pathology evaluation, hydroxyproline content, serum bilirubin, liver enzyme level and magnetic resonance cholangio-pancreatography (MRCP) to assess the stricture.All procedures were completed successfully. The surgical time of the SG was significantly less than the CG (SG: (19.2 ± 4.3) minutes, vs. CG: (29.2 ± 7.1) minutes, P = 0.000). One bile leakage was occurred in either group. No significant difference of intraoperative tolerance pressure of anastomosis, rate of bile leakage and postoperative bursting pressure of anastomosis, anastomotic stricture, hydroxyproline content, serum bilirubin and liver enzyme level was found between the two groups. MRCP showed no anastomosis stricture and obstruction during months of follow-up.The technique of sutureless choledochoduodenostomy with a degradable intraluminal stent is feasible and a safe procedure in this dog model.

Background Rice is highly sensitive to drought, and the effect of drought may vary with the different genotypes and development stages. Genome-wide gene expression profiling was used as the initial point to dissect molecular genetic mechanism of this complex trait and provide valuable information for the improvement of drought tolerance in rice. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice exposed to drought stress. The transcriptome from leaf, root, and young panicle at three developmental stages was comparatively analyzed combined with bioinformatics exploring drought stress related cis-elements. Results There were 5,284 genes detected to be differentially expressed under drought stress. Most of these genes were tissue- or stage-specific regulated by drought. The tissue-specific down-regulated genes showed distinct function categories as photosynthesis-related genes prevalent in leaf, and the genes involved in cell membrane biogenesis and cell wall modification over-presented in root and young panicle. In a drought environment, several genes, such as GA2ox, SAP15, and Chitinase III, were regulated in a reciprocal way in two tissues at the same development stage. A total of 261 transcription factor genes were detected to be differentially regulated by drought stress. Most of them were also regulated in a tissue- or stage-specific manner. A cis-element containing special CGCG box was identified to over-present in the upstream of 55 common induced genes, and it may be very important for rice plants responding to drought environment. Conclusions Genome-wide gene expression profiling revealed that most of the drought differentially expressed genes (DEGs) were under temporal and spatial regulation, suggesting a crosstalk between various development cues and environmental stimuli. The identification of the differentially regulated DEGs, including TF genes and unique candidate cis-element for drought responsiveness, is a very useful resource for the functional dissection of the molecular mechanism in rice responding to environment stress.

An indica pyramiding line, DK151, and its recurrent parent, IR64, were evaluated under drought stress and non-stress conditions for three consecutive seasons. DK151 showed significantly improved tolerance to drought. The DNA methylation changes in DK151 and IR64 under drought stress and subsequent recovery were assessed using methylation-sensitive amplified polymorphism analysis. Our results indicate that drought-induced genome-wide DNA methylation changes accounted for ∼12.1% of the total site-specific methylation differences in the rice genome. This drought-induced DNA methylation pattern showed three interesting properties. The most important one was its genotypic specificity reflected by large differences in the detected DNA methylation/demethylation sites between DK151 and IR64, which result from introgressed genomic fragments in DK151. Second, most drought-induced methylation/demethylation sites were of two major types distinguished by their reversibility, including 70% of the sites at which drought-induced epigenetic changes were reversed to their original status after recovery, and 29% of sites at which the drought-induced DNA demethylation/methylation changes remain even after recovery. Third, the drought-induced DNA methylation alteration showed a significant level of developmental and tissue specificity. Together, these properties are expected to have contributed greatly to rice response and adaptation to drought stress. Thus, induced epigenetic changes in rice genome can be considered as a very important regulatory mechanism for rice plants to adapt to drought and possibly other environmental stresses.

To make reference to cross combinations and improvement of parents, the genetic diversity and relationship among 55 rice germplasms were analyzed with a total of 53 SSR markers. In the present study, 267 allelic variations were detected, and the average allelic variation of 53 loci was 5.04, ranging from 4 to 7. The average polymorphism index content (PIC) of SSR markers was 0.624, ranging from 0.287 to 0.786. All germplasms could be divided into indica and japonica rices, the genetic similarity between them varied from 0.588 to 0.996. The similarity coefficient between Minghui 86 and 53 donors was from 0.655 to 0.850. The similarity coefficient between Shuhui 527 and the donors was from 0.640 to 0.873. The results indicated that the detection of SSR polymorphisms was not only one of the most efficient and accurate measures to study the genetic differences among rice varieties but also was helpful for the discovery and utilization of favorable genes in advanced-backcross introgression populations.

Background Non-host resistance in rice to its bacterial pathogen, Xanthomonas oryzae pv. oryzicola (Xoc), mediated by a maize NBS-LRR type R gene, Rxo1 shows a typical hypersensitive reaction (HR) phenotype, but the molecular mechanism(s) underlying this type of non-host resistance remain largely unknown. Results A microarray experiment was performed to reveal the molecular mechanisms underlying HR of rice to Xoc mediated by Rxo1 using a pair of transgenic and non-transgenic rice lines. Our results indicated that Rxo1 appeared to function in the very early step of the interaction between rice and Xoc, and could specifically activate large numbers of genes involved in signaling pathways leading to HR and some basal defensive pathways such as SA and ET pathways. In the former case, Rxo1 appeared to differ from the typical host R genes in that it could lead to HR without activating NDR1. In the latter cases, Rxo1 was able to induce a unique group of WRKY TF genes and a large set of genes encoding PPR and RRM proteins that share the same G-box in their promoter regions with possible functions in post-transcriptional regulation. Conclusions In conclusion, Rxo1, like most host R genes, was able to trigger HR against Xoc in the heterologous rice plants by activating multiple defensive pathways related to HR, providing useful information on the evolution of plant resistance genes. Maize non-host resistance gene Rxo1 could trigger the pathogen-specific HR in heterologous rice, and ultimately leading to a localized programmed cell death which exhibits the characteristics consistent with those mediated by host resistance genes, but a number of genes encoding pentatricopeptide repeat and RNA recognition motif protein were found specifically up-regulated in the Rxo1 mediated disease resistance. These results add to our understanding the evolution of plant resistance genes.

To assess the value of laparoscopic ultrasonography in laparoscopic hepatectomy.Twenty-two patients with liver diseases underwent laparoscopic ultrasonography. A 10 mm 7.5/10 MHz linear, side viewing laparoscopic ultrasonography probe was used intra-operatively to examine the convergence of intrahepatic biliary ducts and blood vessels, confirm and correct the resection line, guide the laparoscopic resection, examine the tumor margin, and discover the residue of calculi.One additional tumor was detected in one primary liver tumor case during the laparoscopic hepatectomy. Laparoscopic hepatectomy was accomplished successfully in 21 patients one of which had to be transferred to laparotomy due to severe liver cirrhosis and uncontrollable bleeding. The average operation time was 157 min with the average examining and guiding time of 14 min. The intra-operative bleeding amount was 520 ml. No calculus and tumor residue were found. One case of post-operative liver wound bile leakage and one case of subphrenic hydrops were found and they both recovered after drainage.Intra-operative laparoscopic ultrasonography helps evaluate the entire liver and decide the resection line accurately. Under its guiding the laparoscopic hepatectomy can be performed smoothly.

To evaluate the quality of life (QOL) of the patients who received pancreaticoduodenectomy (PD) and work out their long term therapy agents.QOL of 18 cases who received PD (group PD) and 18 cases received laparoscopic cholecystectomy (LC) (group LC) in the same days was determined by symptoms questionnaire and Chinese version SF-36 QOL questionnaire from Jan 2002 to Dec 2003 in Sir Run Run Shaw Hospital.Compared with group LC, the total QOL score and physical health score of group PD didn't have significant decrease. But the mental health score of group PD was lower than group LC (P0.05). Eight different scales of SF-36 questionnaire showed that the score in physical functioning, role-physical, bodily pain, general health, social functioning of group PD was lower than that of group LC. The score in vitality, role-emotional and mental health of group PD was the same as the group LC. According to the symptoms questionnaire, the patient diarrhea and recurrence had obvious influence on PH score. The patient weight loss and unemployment had obvious influence on MH2 score.The QQL of patients received PD didn't have decreased. Their total score of SF-36 QQL was close to the patients who received LC. But the mental health score of group PD was lower than group LC. Weight loss, unemployment, recurrence and chronic pancreatic diarrhea may be infect the Quality of life after PD.

To investigate the clinical effect of laparoscopic radical resection of colon cancer.Patients with colon cancer who underwent radical resection during January 2000 to January 2004 in Sir Run Run Shaw Hospital (Medical College of Zhejiang University) were divided into open and laparoscopic groups for a non-randomized case-control study. All the patients were followed up and their clinical and pathological results were compared.No difference was seen between the two groups on the patients' age, gender, lymph node numbers and Dukes staging. The laparoscopic group had a longer mean operation time [(182 +/- 62) min vs (141 +/- 37) min] and shorter hospital stay [(5.3 +/- 1.9) d vs (8.2 +/- 1.2) d] than the open group. All surgical margins were pathological negative. Post-operation follow up was 12-18 months (mean 21 months). No incision recurrence was found in neither group. As far the local recurrence and distal metastasis rate were similar in both groups.Laparoscopic radical resection of colon cancer has minimal invasion and shorter recuperation than open procedure, the radicalness and either local recurrence or distal metastasis rate after surgery are similar when compared with open group.

To summarize the experience of laparoscopic distal pancreatectomy with preservation of the spleen.From Nov 2003 to Dec 2004, 2 patients with cystic lesions in the body and tail of the pancreas underwent laparoscopic distal pancreatectomy with preservation of the spleen.Both of the operations were successful with the operative time of 220 min and 190 min respectively, and the blood loss were 450 ml and 350 ml. There was no postoperative complication and the pathological diagnosis was pancreatic serous cystadenoma. Both patients' symptom disappeared after operation without recurrence during the follow-up of 18 and 5 months.Laparoscopic distal pancreatectomy with preservation of the spleen is safe and feasible for the management of benign tumor in the body and tail of pancreas with the advantages of reduced injury, earlier recovery and less complication.