[Prevalence of Helicobacter pylori infection and risk factors among family members in Qinghai Province, China].

Objective: To investigate the prevalence of Helicobacter pylori infection among family members, and analyze associated risk factors. Methods: The current investigation was a cross-sectional study. The Qinghai region was stratified into urban areas, agricultural areas, and pastoral areas. The urban areas of Xining City, the agricultural areas of Haidong City, and the pastoral areas of Haibei Tibetan Autonomous Prefecture were selected. A total of 396 resident families (1 131 people) who underwent health checkups from 2021 to 2022 in the above areas were included in the survey study. Questionnaires were administered and H. pylori infection was detected using the 13C-urea breath test. Numerical data were expressed as cases and percentages, and the Chi-square test was used to compare differences in H. pylori infection rates in the populations and families in each group. Multifactorial logistic regression was used to analyze risk factors for H. pylori infection, and P<0.05 was considered statistically significant. Results: The prevalence of H. pylori infection in Qinghai province was 52.8% (597/1 131) and the prevalence of H. pylori infection in households was 80.6% (319/396). In H. pylori-positive households with at least 1 infected spouse, 40.4% (36/89) had only 1 infected spouse, and in 59.6% (53/89) both spouses were infected. In analysis of children infected by parents with H. pylori, 20.0% (9/45) of households had fathers and children infected, 48.9% (22/45) had mothers and children infected, and 31.1% (14/45) had both parents and children infected. In univariate analysis there was a statistically significant difference in the overall comparison of H. pylori infection rates among families with different numbers of people living together (χ2=11.12, P=0.004), and between-group comparisons suggested that H. pylori infection rates were higher in families with 4 or 5 people and more than 5 people living together than in families with 2 or 3 people living together. The H. pylori infection rate was higher in families that did not use serving chopsticks and spoons during family meals than in families that did use serving chopsticks and spoons (χ2=6.12, P=0.013). In multifactorial logistic regression analyses the number of people living together in a family and whether or not serving chopsticks and spoons were used at family meals were associated with H. pylori infection (P<0.05). Conclusion: The H. pylori infection rate in families in Qinghai Province is high, and there is a clear association with family aggregation. It is more common for both members of a couple to be infected, and H. pylori infection of a mother has a greater effect on the children's infection status than H. pylori infection of a father. The infection rate of H. pylori was lower in families that used serving chopsticks and spoons during dinner gatherings, and the fewer the number of people living together in the family, the lower the H. pylori infection rate.

[A deep-learning model for the assessment of coronary heart disease and related risk factors via the evaluation of retinal fundus photographs].

Objective: To develop and validate a deep learning model based on fundus photos for the identification of coronary heart disease (CHD) and associated risk factors. Methods: Subjects aged>18 years with complete clinical examination data from 149 hospitals and medical examination centers in China were included in this retrospective study. Two radiologists, who were not aware of the study design, independently evaluated the coronary angiography images of each subject to make CHD diagnosis. A deep learning model using convolutional neural networks (CNN) was used to label the fundus images according to the presence or absence of CHD, and the model was proportionally divided into training and test sets for model training. The prediction performance of the model was evaluated in the test set using monocular and binocular fundus images respectively. Prediction efficacy of the algorithm for cardiovascular risk factors (e.g., age, systolic blood pressure, gender) and coronary events were evaluated by regression analysis using the area under the receiver operating characteristic curve (AUC) and R2 correlation coefficient. Results: The study retrospectively collected 51 765 fundus images from 25 222 subjects, including 10 255 patients with CHD, and there were 14 419 male subjects in this cohort. Of these, 46 603 fundus images from 22 701 subjects were included in the training set and 5 162 fundus images from 2 521 subjects were included in the test set. In the test set, the deep learning model could accurately predict patients' age with an R2 value of 0.931 (95%CI 0.929-0.933) for monocular photos and 0.938 (95%CI 0.936-0.940) for binocular photos. The AUC values for sex identification from single eye and binocular retinal fundus images were 0.983 (95%CI 0.982-0.984) and 0.988 (95%CI 0.987-0.989), respectively. The AUC value of the model was 0.876 (95%CI 0.874-0.877) with either monocular fundus photographs and AUC value was 0.885 (95%CI 0.884-0.888) with binocular fundus photographs to predict CHD, the sensitivity of the model was 0.894 and specificity was 0.755 with accuracy of 0.714 using binocular fundus photographs for the prediction of CHD. Conclusion: The deep learning model based on fundus photographs performs well in identifying coronary heart disease and assessing related risk factors such as age and sex.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data].

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

Differentially Expressed Homologous Genes Reveal Interspecies Differences of Paragonimus Proliferus based on Transcriptome Analysis.

Paragonimus proliferus (P. proliferus), one of 46 Paragonimus species registered in the National Center for Biotechnology Information database, may be much more widely distributed in Southeast Asia than previously thought, as its reported natural foci have increased in the past decades. However, very little is known about its molecular biology, especially at the transcriptome level. For the first time, the transcriptome of this species was sequenced and compared with four other common Paragonimus species, namely Paragonimus skrjabini, Paragonimus kellicotti, Paragonimus miyazakii, and Paragonimus westermani, to predict homologous genes and differentially expressed homologous genes to explore interspecies differences of Paragonimus proliferus. A total of 7393 genes were found to be significantly differentially expressed. Of these, 49 were considered to be core genes because they were differentially expressed in all four comparison groups. Annotations revealed that these genes were related mainly to "duplication, transcription, or translation", energy or nutrient metabolism, and parasitic growth, proliferation, motility, invasion, adaptation to the host, or virulence. Interestingly, a majority (5601/7393) of the identified genes, and in particular the core genes (48/49), were expressed at lower levels in P. proliferus. The identified genes may play essential roles in the biological differences between Paragonimus species. This work provides fundamental background information for further research into the molecular biology of P. proliferus.

[Surgical analysis of transnasal frontal sinus balloon dilatation].

Objective:To compare the clinical efficacy and safety of frontal sinus balloon for frontal sinus surgery with frontal sinus balloon dilatation and conventional frontal sinus surgery. Method:One thousand four hundred and eighty-nine cases from 2013 to 2018 were collected. The surgical methods included frontal sinus balloon dilatation, frontal sinus balloon assisted FESS and Stammberger frontal sinus removal. The preoperative and postoperative data of 1 125 patients were collected and the rate of loss of follow-up was 24.44%. All patients underwent endoscopic, CT and symptom scores before and after operation. The postoperative follow-up period ranged from 6 months to 8 years. The postoperative nasal endoscopy and CT review were recorded. Lund-Kenndy endoscopic scores were performed on the frontal sinus mucosa of patients 1-6 months after surgery. Result:In the simple frontal sinus balloon dilatation group, 59 cases were cured, 37 cases were cured, 20 cases were improved, 2 cases were ineffective, and the frontal sinus opening rate was 96.61%. The frontal sinus balloon assisted FESS group was 609 cases, 381 cases were cured, and 169 cases were improved. There were 59 cases ineffective, 8 of which were cured after the second operation, and the frontal sinus opening rate was 90.31%; Stammberger went to the eggshell group in 457 cases, recovered 285 cases, improved in 122 cases, and ineffective in 50 cases, including 13 cases. After the second operation, the patient was cured after the second operation. Two cases of postoperative sinus ostium adhesions were cured. The balloon was dilated after the expansion of the outpatient clinic. The frontal sinus opening rate was 89.06%. Nasal endoscopy scores were statistically analyzed using SPSS 19.0 software. Conclusion:Frontal sinus balloon dilatation is suitable for most frontal sinus lesions and is safer than traditional endoscopic frontal sinus surgery. Compared with Stammberger's eggshell surgery, frontal sinus balloon dilatation has the advantages of simple and easy operation, short learning curve, convenient and accurate, and worthy of clinical promotion.

[The 465th case: intestinal obstruction, gastrointestinal hemorrhage and duodenal fistula].

This is a complicated and difficult case. The onset symptom of a 62-year-old male was recurrent intestinal obstruction. Ileocecal and ileocolic operation was done twice. Massive gastrointestinal bleeding occurred due to giant fistula of descending duodenum, which connected to ileocolic anastomosis. After consultation by multidisciplinary team, jejunal-feeding tube was placed to provide enteral nutrition. With general condition improving, duodenal fistula repair and involved bowel resection were performed. Postoperative pathology confirmed Crohn's disease. The patient was treated with thalidomide and recovered well during follow-up.

Correlation between RAR-ß expression in lung squamous cell carcinoma tissues and prognosis.

OBJECTIVE: To explore the retinoic acid receptor-ß (RAR-ß) expression in lung squamous cell carcinoma (LSCC) tissues and its prognosis. PATIENTS AND METHODS: SP assay was used to detect the RAR-ß expression in 100 cases of surgically resected LSCC tissues and 20 cases of peritumoral normal lung tissues, and prognosis follow-up was conducted. RESULTS: The overall positive expression rate of RAR-ß was 54.00%, which was not correlated with age, gender, phase and pathological type (p>0.05). Stratified analysis showed that the prognosis of patients with positive IRAR-ß expression in phase I was significantly better than that of those with negative IRAR-ß expression, in which the median survival times were 31 and 22 months respectively (p=0.022). In contrast, the prognosis of patients with negative RAR-ß expression was better than that of those with positive RAR-ß expression in phase II and III A. The median survival times were 23 and 16 months respectively in phase II p = 0.008, and 19 and 7 months respectively in phase III A (p=0.019). CONCLUSIONS: RAR-ß is expressed in LSCC tumor tissues. RAR-ß expression, which is not significantly correlated with the clinicopathological characteristics of patients, affects the postoperative survival of LSCC patients in phase I and II-III A dually. RAR-ß expression state is one of the independent factors for the prognosis of LSCC patients.

[Rectal gastrointestinal stromal tumor: a clinical and pathologic analysis].

OBJECTIVE: To investigate the clinicopathologic characteristics and therapy of rectal gastrointestinal stromal tumors (GISTs). METHODS: Clinical findings, morphologic features, immunophenotype and prognosis of 53 cases (58 samples) of rectal GISTs were investigated. RESULTS: Thirty-three patients were male and 20 were female. The age of patients ranged from 19 to 81 years, with an average of 49.7 years. The main symptoms included rectal disorders in 29 patients and vaginal mass in 2 patients, while the tumors in 22 patients were found by routine physical examination. Thirty-five primary GISTs were resected completely without preoperative therapy, and thirteen tumors were resected after therapy of imatinib. Five tumors were recurrent. Imatinib therapy in 13 patients led to smaller and softer tumor mass grossly and decreased cellularity and marked degeneration histologically. Of the 35 primary rectal GISTs, there were 17 (48.6%), 6 (17.1%), 0(0), and 12 (34.3%) cases diagnosed as very low risk, low risk, medium risk, and high risk respectively. Eight cases had tumor of 1 cm or less in diameter. In the five recurrent cases, the tumors showed increased cellularity, mitotic figures, and Ki-67 index. Imatinib therapy led to smaller and softer tumor mass grossly and decreased cellularity and marked degeneration histologically. Immunohistochemical stains showed CD117, DOG1, and CD34 positivity, S-100 protein negativity and indefinite SMA stain. CONCLUSIONS: Rectal GISTs are rare tumors with a male predominance.Patients without obvious sypmtoms are found by themselves and by routine physical examination. The tumor diameter less than 2 cm is common while larger than 5 cm is few. Diagnosis of rectal GISTs is easily made by biopsy and patients often acquire preoperative therapy for preserving anal sphincter function.

Protective and sensitive effects of melatonin combined with adriamycin on ER+ (estrogen receptor) breast cancer.

OBJECTIVE: This study aims to investigate the protective and sensitive effects of melatonin (MLT) in the treatment of breast cancer. MATERIALS AND METHODS: ER+ breast cancer rat model was established and then rats were randomly divided into five different groups as follows: control group, Diss group, adriamycin (ADM) group, MLT group, and MLT combined with adriamycin (M+A) group. Tumor weights and one month survival rate were compared among these groups. In addition, changes of tumor tissues and expression of E-cadherin were observed under optical microscopy or electro-microscopy. RESULTS: Tumor weights were significantly lighter in M+A group than those in ADM group (p < 0.05). Under optical and electro-microscopy, tumor cell apoptosis was obviously increased in MLT group, and tumor cell injury was more severe in M+A group than that in ADM group; additionally, expression of E-cadherin was higher in MLT group and M+A group than that in other groups. Moreover, MLT group had the highest one month survival rate (100%), there was the poorest life quality in ADM group, but the best life quality in MLT. CONCLUSION: MLT could enhance the sensitivity of tumor to ADM in vivo and improve patient's life quality.

Elicitation and in situ adsorption enhanced secondary metabolites production of Tripterygium wilfordii Hook. f. adventitious root fragment liquid cultures in shake flask and a modified bubble column bioreactor.

The experiments of elicitation and in situ adsorption were conducted in shake flasks and then tested in a modified bubble column bioreactor for enhancing the productions of three active metabolites in Tripterygium wilfordii Hook. f., triptolide, wilforgine and wilforine. Methyl jasmonate was screened out as the elicitor and the non-ionic polymeric ion-exchange resin of Amberlite(®) XAD-7 was used for in situ product removal and protecting the alkaloids from degradation in the medium. In shake flask experiments, 3.55-fold, 49.11-fold, and 10.40-fold of triptolide, wilforgine, and wilforine, respectively, could be recovered from the medium and XAD-7 resin by elicitation and in situ product removal, compared with the control. The modified 10 L bubble column bioreactor had similar productions of the three active metabolites but needed a further optimization of parameters for better growth of adventitious roots.

Repellent activity screening of 11 kinds of essential oils against Aedes albopictus Skuse: microcapsule preparation of Herba Schizonepetae oil and repellent bioassay on hand skin.

BACKGROUND: The main ingredient of most repellents on the market is DEET, an effective compound that has the disadvantages of toxic reactions as well as damaging effects on plastic and synthetic fabric. DEET alternatives are urgently needed. METHODS: The repellent activities of 11 kinds of essential oils were tested against Aedes albopictus Skuse by a Y-tube olfactometer. Using essential oils with high repellent activity as core material and gelatin and gum arabic as wall materials, we prepared microcapsules of essential oils and optimized the preparation process. The microcapsule formulation was then subjected to repellent bioassay on hand skin. RESULTS: when the dosage of essential oils was 5 µL, the cinnamon oil repellent rate was 87.5% within 10 min and the Herba Schizonepetae oil (HSO) repellent rate was 98.0% within 3 min. Up to 1.5% (w/v) gelatin and 1.5% (w/v) gum arabic (as wall materials), and HSO (as core material) were used to form microcapsules with a 1:1 ratio of core material to wall material. CONCLUSION: The ointment preparations effectively protected hand skin exposed to a high-density A. albopictus Skuse rearing cage for 4-5 h. The HSO microcapsule repellent has broad application and development prospects.

Treatment strategy for early gastric cancer.

Gastric cancer ranks the second leading cause of cancer-specific mortality worldwide. With a poor prognosis, 5-year survival rate of gastric cancer is less than 20%-25% in the USA, Europe, and China [1]. However, early gastric cancer(EGC) offers an excellent (over 90%) chance of cure based on surgical resection [2]. As the increasing detection of EGC, more treatment options have been developed both curatively and minimally invasively to maintain a good quality of life(QOL). One of the advanced therapeutic techniques is endoscopic dissection. Improvements in surgical treatment include minimizing lymph node dissection, reconstruction methods, laparoscopy-assisted surgery, and sentinel node navigation surgery(SNNS) [3]. With technological advances, even Natural Orifice Transluminal Endoscopy Surgery (NOTES) and robotic surgery are expected to represent the next revolution [4]. However, there still remains much dispute among these treatments, which arouses further clinical trials to verify. Update of the treatments, controversial indications, prognosis and current strategies for EGC are discussed in this review.

Estival distribution of dissolved metal concentrations in Liaodong Bay.

The temporal and spatial distributions of Cu, Pb, Zn, and Cd in surface water of the Liaodong Bay were studied based on samples collected at 16 sites in June and August from 2001 to 2005. The temporal distribution showed decreasing trends. The concentrations of dissolved metals in the Liaodong Bay were 4.34, 3.21, 31.54, and 0.995 mug/L for Cu, Pb, Zn, and Cd, respectively. Cu and Pb were scattered near the estuaries, and Zn and Cd were mainly found near the Wuli River. Rivers were the main metals pollution sources in the Bay.

Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. II: type I resistance.

Fusarium head blight (FHB) is a serious disease in wheat and barley affecting both yield and quality. To identify genes for resistance to infection, the RIL population derived from 'Nanda2419' x 'Wangshuibai' and the parents were evaluated for percentage of infected spikes (PIS) in four different environments. Using a 2,960 cM marker framework map constructed for this population, ten chromosome regions were detected for their association with type I resistance through interval mapping with Mapmaker/QTL, among which QTLs mapped in the intervals of Xwmc349--Xgwm149 on chromosome 4B, of Xwmc96--Xgwm304 on chromosome 5A and of Xgwm408--Xbarc140 on chromosome 5B were revealed in at least three environments and have Wangshuibai as the source of resistance alleles. Qfhi.nau-4B and Qfhi.nau-5A had larger effects and explained up to 17.5 and 27.0% of the phenotypic variance, respectively. To detect epistasis QTLs, two-locus interactions were examined by whole genome scan. Interactions of five locus pairs were found to have significant effects on type I resistance with the LOD score ranging 3.8-6.5 and four of them conferred resistance in parental phase. The one with the most significant effect was Xcfd42--Xgwm469 (6D)/Xwmc390-2--Xbd04 (2A) pair. No QTL x E interaction was detected for PIS. It was found that flowering time did not have significant effects on PIS in this population. Our studies indicated that Wangshuibai is useful for breeding for both type I and type II scab resistance and the markers associated with the QTLs could be used in marker-assisted selection and isolation of scab-resistance QTLs.

Two new saponins from the bud of Aralia elata (Miq.) Seem.

Two new saponins, named congmuyanoside A and congmuyanoside B, have been isolated from the buds of Aralia elata (Miq.) Seem. Their structures have been determined on the basis of chemical and spectroscopic evidence.

Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. I. Type II resistance.

Scab disease caused by Fusarium spp. has been a major concern for both wheat producers and consumers. Deployment of scab-resistant varieties is the major strategy to curb this disease. To identify the scab resistance genes in wheat cv. Wangshuibai, we produced a F(6:7) recombinant inbred line (RIL) population by crossing Wangshuibai with the scab-susceptible cultivar Nanda2419. The RILs were evaluated for scab resistance in the field by single floret inoculation in two replicates in 2002 and one replicate in 2003. The number of diseased spikelets (NDS) and the length of diseased rachides (LDR) were investigated to reflect the Type II resistance. Among 654 simple sequence repeat (SSR) markers surveyed, 326 were found to be polymorphic between the parents. A partial molecular map was constructed with these markers that covered over 2,210 cM of the wheat genome. Six chromosome regions showed association with both NDS and LDR in a one-way anova analysis, even though the variation explained by them varied between the two traits. Eight intervals were detected for their association with Type II resistance through interval mapping, five of which were not identified in single-point analysis. The quantitative trait loci (QTL) with large effects were the ones in the interval of Xgwm533-3-Xgwm533-1 on chromosome 3B and in the interval of Xwmc539-Xbarc024 on chromosome 6B, whose alleles favoring resistance originate from Wangshuibai. In addition, a QTL whose resistance allele originated from Nanda2419 was consistently detected in the interval of Xs1021m-Xgwm47-1 on chromosome 2B. These results suggest that Wangshuibai is the major source for Type II resistance in this population. The markers associated with these QTL would facilitate the use of scab-resistant genes of Wangshuibai in scab resistance breeding programs of wheat.

PCR-based markers for the powdery mildew resistance gene Pm4a in wheat.

Gene tagging is the basis of marker-assisted selection and map-based cloning. To develop PCR-based markers for Pm4a, a dominant powdery mildew resistance gene of wheat, we surveyed 46 group 2 microsatellite markers between Pm4a near-isogenic line (NIL) CI 14124 and the recurrent parent Chancellor (Cc). One of the markers, gwm356, detected polymorphism and was used for genotyping an F(2) population of 85 plants derived from CI 14124 x Cc. Linkage mapping indicated that Xgwm356 was linked to Pm4a at a distance of 4.8 cM. To identify more PCR-based markers for Pm4a, we also converted the restriction fragment length polymorphism marker BCD1231 linked to it into a sequence-tagged site (STS) marker. The STS primer designed based on the end sequences of BCD1231 amplified an approximately 1.6-kb monomorphic band in both parents. Following digestion of the products with the four-cutter enzymes HaeIII and MspI, it was discovered that the band from CI 14124 consisted of at least two products, one of which had a digestion pattern different from the band from Cc. In the F(2) population, the cleaved polymorphism revealed by the STS marker between the parents co-segregated with powdery mildew resistance. To design Pm4a-specific PCR markers, the 1.6-kb band from Cc and the fragment associated with Pm4a in CI 14124 were sequenced and compared. Based on these sequences a new PCR marker was identified, which detected a 470-bp product only in the Pm4a-containing lines. These PCR-based markers provide a cost-saving option for marker-assisted selection of Pm4a.

[Molecular markers linked to dwarf gene Rht3 in wheat].

The dwarf gene Rht3 derived from Tom Thumb variety, a Tibetan wheat of China, is a dominant gene with the insensitivity to gibberellic acid. Rht3 shows to depress alpha-amylase activity and hence enchance the resistance to preharvest sprouting mainly through its effect on the expression of alpha-Amy1. Near isogenic lines with Rht3 and their segregating population were analyzed by PCR and RFLP techonology. In RAPD analysis, out of 310 random primers (10 bp) screened, only three primers of UBC389, OPV-06 and S1060 revealed polymorphisms in NIL from 310 random primers. Fragments S1060(1900) and S1060(2000) amplified by primer S1060 were shown to be linked to Rht3 with a genetic distance 7.1 cM and 9.2 cM. Fifty-three probes specific for short arms of homoeologous group 4 were screened in RFLP analysis. Xpsr584, XksuF8 and Xcdo38 showed polymorphisms between the NIL. The linkage analysis indicateded that Xpsr584 was linked to Rht3 with a genetic distance 8.0 cM.