Introgression of bacterial leaf blight (BLB) resistant gene, Xa7 into MARDI elite variety, MR219 by marker assisted backcrossing (MABC) approach

Abstract Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.

Resumo A mancha bacteriana das folhas (BLB) é uma das principais doenças do arroz na Malásia. Essa doença causa perdas substanciais de rendimento de até 70%. O desenvolvimento de variedades de arroz que herdaram características de resistência ao BLB é uma abordagem crucial para promover e sustentar a indústria do arroz na Malásia. Portanto, o objetivo deste estudo foi aumentar os caracteres BLB resistentes a doenças da variedade comercial MR219 de alto rendimento por meio de uma abordagem de cruzamento retrocruzamento com ferramenta de apoio de seleção assistida por marcador (MAS). O gene de resistência a BLB de amplo espectro, Xa7 do pai doador IRBB7, foi introgressado no MR219 suscetível (pai recorrente) usando dois marcadores flanqueadores ID7 e ID15. No BC3F4, conseguimos gerar 19 linhagens introgressadas com o gene Xa7 homozigoto e apresentamos características de resistência como genitor doador quando desafiado com Xanthomonas oryzae pv. oryzae por inoculação artificial. O pai recorrente MR219 e a variedade controle, MR263, estavam gravemente infectados pela doença. As linhas melhoradas exibiram características morfológicas e de desempenho de rendimento semelhantes às da variedade elite, MR219. Duas linhas, PB-2-107 e PB-2-34, foram escolhidas como linhas potenciais por causa de seus desempenhos excelentes em comparação com a mãe, MR219. Este estudo demonstra uma história de sucesso de aplicação de MAS no desenvolvimento de linhas de arroz melhoradas com resistência a doenças contra a doença BLB.

Introgression of bacterial leaf blight (BLB) resistant gene, Xa7 into MARDI elite variety, MR219 by marker assisted backcrossing (MABC) approach / Introdução do gene resistente à ferragem da folha bacteriana (BLB), xa7 na variedade MARDI elite, MR219 por abordagem de backcrossing assistida por marcador (MABC)

Abstract Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.

Resumo A mancha bacteriana das folhas (BLB) é uma das principais doenças do arroz na Malásia. Essa doença causa perdas substanciais de rendimento de até 70%. O desenvolvimento de variedades de arroz que herdaram características de resistência ao BLB é uma abordagem crucial para promover e sustentar a indústria do arroz na Malásia. Portanto, o objetivo deste estudo foi aumentar os caracteres BLB resistentes a doenças da variedade comercial MR219 de alto rendimento por meio de uma abordagem de cruzamento retrocruzamento com ferramenta de apoio de seleção assistida por marcador (MAS). O gene de resistência a BLB de amplo espectro, Xa7 do pai doador IRBB7, foi introgressado no MR219 suscetível (pai recorrente) usando dois marcadores flanqueadores ID7 e ID15. No BC3F4, conseguimos gerar 19 linhagens introgressadas com o gene Xa7 homozigoto e apresentamos características de resistência como genitor doador quando desafiado com Xanthomonas oryzae pv. oryzae por inoculação artificial. O pai recorrente MR219 e a variedade controle, MR263, estavam gravemente infectados pela doença. As linhas melhoradas exibiram características morfológicas e de desempenho de rendimento semelhantes às da variedade elite, MR219. Duas linhas, PB-2-107 e PB-2-34, foram escolhidas como linhas potenciais por causa de seus desempenhos excelentes em comparação com a mãe, MR219. Este estudo demonstra uma história de sucesso de aplicação de MAS no desenvolvimento de linhas de arroz melhoradas com resistência a doenças contra a doença BLB.

Production and characterization of poly-3-hydroxybutyrate from crude glycerol by Bacillus sphaericus NII 0838 and improving its thermal properties by blending with other polymers

The aim of this work was to study the production of poly-3-hydroxybutyrate (PHB) under nitrogen limited conditions by Bacillus sphaericus NII 0838 using crude glycerol from biodiesel industry as sole carbon source. Effect of various process parameters on PHB production such as glycerol concentration, inoculum size and pH of the medium were optimized. Characterization of extracted PHB was carried out by FT-IR, ¹H and 13C NMR. Results showed that the bacterial culture accumulated about 31 percent PHB in crude glycerol medium. The extracted PHB was blended with other polymers to improve its physical characteristics. The thermal properties of the polymer like melting temperature (Tm) and heat of fusion (ΔHf) were determined using DSC.

Impact of a comprehensive telephone-based disease management programme on quality-of-life in patients with heart failure.

BACKGROUND: Disease management programmes for patients with heart failure have improving the quality-of-life (QOL) of patients with heart failure. METHODS: Patients attending the heart failure clinic were randomized into 2 groups of 25 patients each. The control group was managed in the heart failure clinic and the intervention group underwent the following additional interventions: (i) interactive sessions with the patient and spouse informing them about the disease, drugs, and self-management of fluid intake and diuretic dose; (ii) a telephonic helpline was established and regular telephone calls made to reinforce the information and modify drug dosages. The QOL was assessed using the Kansas City Cardiomyopathy questionnaire. Functional capacity was assessed by the 6-minute walk test. Continuous variables were compared with the Student t-test (paired or unpaired). RESULTS: There was significant improvement in the QOL and functional capacity of patients in the intervention group compared with controls over a 6-month period. The mean (SD) QOL scores in the intervention group improved from 60.0 (23.6) to 76.3 (17.3) but did not change significantly in the control group (62.2 [22.6] to 63.4 [21.9]). There was a similar improvement in the functional capacity measured by the 6-minute walk test in the intervention group (from 202.2 [81.5] to 238.1 [100.9] metres, p < 0.05) but not in the control group (193.8 [81.5] to 179.7 [112.0] metres). In the intervention group, the use of beta-blockers and angiotensin-converting enzyme inhibitors was similar but in the intervention group patients were placed on higher doses. There was no significant difference in the number of emergency room visits or admissions in either group. For every 20 patients in the intervention group, 14 patients improved by 1 functional class while in the control group this was observed in only 3 patients for every 20 treated. CONCLUSION: This study demonstrates that in the setting of a developing country, improvement in QOL by intensive management of heart failure patients through a heart failure programme with telephonic reinforcement and a helpline is greater than that usually achieved with drug therapy in a routine heart failure clinic.

Splenic abscess as a complication of acute pancreatitis.

Though there is close anatomical proximity between pancreas and the spleen, the involvement of latter is extremely uncommon in acute inflammation of the pancreas. In this report, we present a case of splenic abscess as a complication of acute pancreatitis. The aspirate from the abscess yielded the organism, Klebsiella. We were able to successfully treat this case with percutaneous drainage along with parenteral antibiotics, and we did not have a resort to splenectomy.

Gastric acid study in patients operated on for perforated duodenal ulcer.

OBJECTIVES: To determine the acid secretory status of patients operated on for perforated duodenal ulcer, with or without prior history suggestive of acid-peptic disease. METHOD: Basal and peak acid output were measured in 48 patients with perforated duodenal ulcer who were treated by simple closure alone, 10 patients with uncomplicated chronic duodenal ulcer and 30 normal controls. Patients operated on for perforated duodenal ulcer were analyzed according to presence (or absence) and duration of prior history of acid-peptic disease. RESULTS: Peak acid output was similar in controls and patients with perforated duodenal ulcer with no prior symptoms. However, patients with prior symptoms had significantly higher peak acid output, similar to those with uncomplicated duodenal ulcer. CONCLUSION: Patients with perforated duodenal ulcer with no antecedent history of acid-peptic disease have normal gastric acid output. These patients may therefore have other etiological factors for their ulcers.

Neuroblastoma with testicular metastasis. Review of literature and report of a case.

Eventhough neuroblastoma presents with wide spread tumour dissemination, metastasis to testes had rarely been reported. We report a case of Stage IV neuroblastoma who developed metastasis to both testes. He had massive infra-diaphragmatic disease with involvement of left supraclavicular lymph node at presentation. Treatment received by him was not adequate and five months later he developed metastasis to both testes. Hematogenous spread might have been the possibility in this case.

Biochemical assessment of cholelithiasis.

Bile and serum were analysed in 45 cases of cholelithiasis and 25 control subjects for cholesterol, phospholipids, bilirubin, alkaline phosphatase and LCAT activity. Serum phospholipids were found to be elevated in sixty percent of cases, whereas phospholipids in bile were found to be decreased. Serum alkaline phosphatase and alanine aminotransferase were normal. Serum and bile LCAT activity was found to be significantly depressed.

Endoscopic sclerotherapy versus propranolol in prevention of recurrent variceal bleeding in patients with child's B and C cirrhosis: a preliminary report.

Thirty two patients with cirrhosis of the liver of Child's B and C class and an episode of endoscopically proven variceal bleed were randomly assigned to receive endoscopic sclerotherapy (EST) or oral propranolol for the prevention of recurrent upper gastrointestinal bleeding. EST was performed at 3 week intervals using 1% polidocanol intravariceally, till eradication of varices. Propranolol dose was adjusted to reduce the resting heart rate by 25% of the basal value (mean +/- SD, 194.3 +/- 63.9 mg/day) Two patients in the propranolol group were excluded within 48 hours due to side effects of the drug. Thirty patients (EST-16, propranolol-14) completed the trial. Patients were followed up for a maximum of 480 days. Mean follow-up in the EST and propranolol groups was 217 and 243 days respectively. The median bleeding free intervals were 480 and 194 days and number of rebleeding episodes was eight and 16 respectively in the EST and propranolol groups (both p = ns). Our study suggests a trend in favor of EST in preventing variceal rebleeding in patients with hepatic cirrhosis who belong to Child's B and C classes.

Epidemiological study of coronary heart disease in Gujaratis in Delhi (India).

A community based survey of coronary heart disease (CHD) was carried out in Gujarati families settled in Delhi. The number of adults surveyed in the age group 25-64 yr was 1317. CHD was diagnosed either on the basis of clinical history supported by documentary evidence of treatment in the hospital or at home or on ECG evidence in accordance with the Minnesota Code. The prevalence rate of CHD on clinical history was 25.1 (28.2 in males and 22.4 in females) per 1000 adults (25-64 yr). The prevalence rates were slightly lower in Gujaratis than the general Delhi urban population. The prevalence rate based on both clinical history and ECG criteria was estimated at 66.8 as compared to 96.8/1000 in general urban Delhi population. The risk factors for CHD such as socio-economic status, family history, obesity, smoking, physical activity and hypertension were studied. The mean and 5th, 50th and 95th percentile values of blood lipids were also estimated in CHD patients and compared with the control group. Hypertension ranked the leading risk factor. Prevalence rate of CHD was higher in the upper socioeconomic group. The positive correlation of higher levels of serum lipids e.g., total cholesterol, low density lipoprotein cholesterol (LDL-C) and triglyceride with CHD was confirmed.

Epidemiological study of coronary heart disease in urban population of Delhi.

A community based survey of coronary heart disease (CHD) was carried out on a random urban sample of 13,723 adults in the age group 25-64 yr in Delhi, India. CHD was diagnosed either on the basis of clinical history supported by documentary evidence of treatment in a hospital or at home; or on ECG evidence in accordance with the Minnesota Code. The overall prevalence of CHD based on clinical history, was 31.9 (39.5 in males and 25.3 in females) per 1000 adults in this age group. The number of patients with CHD increased with advancing age in both sexes. The total prevalence rate based on both clinical history and ECG criteria (asymptomatic patients with ECG changes of definite myocardial infarction and ST-T changes suggestive of CHD) was estimated as 96.7/1000 adults in this age group. Analysis of information on socio-economic status, family history of CHD, obesity, hypertension and smoking obtained from this sample of 13,723 adults suggested that hypertension had the strongest association with CHD. Obesity, diabetes and family history were also found to be associated with CHD. It should, however, be noted that risk factor assessments in CHD can be done satisfactorily only through incidence studies.

Prevalence, awareness & treatment status of hypertension in urban population of Delhi.

A community based survey for the prevalence of hypertension was carried out on a random urban sample of 13,723 adults in the age group 25-64 yr from the Union Territory of Delhi (India). Hypertension was defined as systolic pressure greater than 160 mm Hg and/or a diastolic pressure greater than 90 mm Hg or a history of current antihypertensive medication. The overall prevalence rate/1000 adults was 127.5 (116.6 in males and 136.8 in females). Mild hypertension (diastolic pressure between 91-104 mm Hg) predominated in the whole group, the proportion decreasing with increasing age in both sexes. Fifty per cent of the hypertensives were aware of their problem, the awareness being slightly higher in females (51.8% versus 46.5%). Approximately 30 per cent of the hypertensives were on medication for high blood pressure. The status control of blood pressure was low in the population, being only 9 per cent, with little difference between the two sexes. The study emphasises the enormity of the problem of hypertension in an urban population in India and poor control of blood pressure achieved in the community.

Acute chlorine poisoning. A study of 84 cases.

Eighty four cases with acute chlorine poisoning who reported between 1/2 hour to 2 hours after exposure were studied. A majority presented with features of upper respiratory tract involvement like irritative cough (70 cases) and oropharyngeal pruritus (60 cases). Bronchospasm was present in 15 cases. None of them had any residual impairment of pulmonary function 4 weeks after exposure.