DRR Dhan 58, a Seedling Stage Salinity Tolerant NIL of Improved Samba Mahsuri Shows Superior Performance in Multi-location Trials.

BACKGROUND: Improved Samba Mahsuri (ISM) is an elite, high-yielding, bacterial blight resistant, fine-grained rice variety with low glycaemic index. It is highly sensitive to salt stress, particularly at seedling stage, which significantly reduces its yield potential in coastal areas. A salinity tolerant QTL, Saltol, associated with seedling stage tolerance was previously mapped on chromosome 1 (10.6-11.5 Mb) from the Indian landrace, Pokkali and is effective in different genetic backgrounds. The objective of this study was to enhance salinity tolerance of ISM by incorporating the Saltol QTL through marker-assisted backcross breeding using the breeding line, FL478 (Pokkali/IR29). RESULTS: Foreground selection was carried out at each generation using five Saltol-specific markers and three bacterial blight resistance genes, Xa21, xa13 and xa5. Background selection was conducted using 66 well distributed polymorphic SSR markers and at the BC3F2 generation, a single plant with maximum recurrent parent genome recovery (95.3%) was identified and advanced to the BC3F4 generation. Based on bacterial blight resistance, seedling stage salinity tolerance and resemblance to ISM, four advanced breeding lines were selected for testing in replicated experiments near Hyderabad, India. A promising near-isogenic line, DRR Dhan 58, was evaluated in multi-location trials-coastal salinity and it showed significant salinity tolerance, resistance to bacterial blight disease, high yield and excellent grain quality during the 2019 and 2020 trials. DRR Dhan 58 was 95.1% similar to ISM based on genotyping with the 90 K SNP chip. Whole genome resequencing analysis of Pokkali and FL478 which were salinity tolerant checks, ISM and DRR Dhan 58 showed a high degree of relatedness with respect to the candidate gene loci for Saltol and OsSKC1 (Shoot K+ Concentration 1). CONCLUSION: DRR Dhan 58, possessing Saltol and three bacterial blight resistance genes (Xa21, xa13 and xa5) in the genetic background of the Indian mega-variety of rice, Samba Mahsuri, was developed for potential cultivation in areas prone to seedling stage salinity, as well as areas with endemic bacterial blight disease. This entry had a 24% yield advantage over the recurrent parent ISM under coastal saline conditions in multi-location trials and was recently released for commercial cultivation in India.

Evaluation of genotype by environment interaction and adaptability in lowland irrigated rice hybrids for grain yield under high temperature.

Recent predictions on climate change indicate that high temperature episodes are expected to impact rice production and productivity worldwide. The present investigation was undertaken to assess the yield stability of 72 rice hybrids and their parental lines across three temperature regimes over two consecutive dry seasons using the additive main effect and multiplicative interaction (AMMI), genotype and genotype × environment interaction (GGE) stability model analysis. The combined ANOVA revealed that genotype × environment interaction (GEI) were significant due to the linear component for most of the traits studied. The AMMI and GGE biplot explained 57.2% and 69% of the observed genotypic variation for grain yield, respectively. Spikelet fertility was the most affected yield contributing trait and in contrast, plant height and tiller numbers were the least affected traits. In case of spikelet fertility, grain yield and other yield contributing traits, male parent contributed towards heat tolerance of the hybrids compared to the female parent. The parental lines G74 (IR58025B), G83 (IR40750R), G85 (C20R) and hybrids [G21 (IR58025A × KMR3); G3 (APMS6A × KMR3); G57 (IR68897A × KMR3) and G41 (IR79156A × RPHR1005)] were the most stable across the environments for grain yield. They can be considered as potential genotypes for cultivation under high temperature stress after evaluating under multi location trials.

Grain Fe and Zn content, heterosis, combining ability and its association with grain yield in irrigated and aerobic rice.

Genetic improvement of rice for grain micronutrients, viz., iron (Fe) and zinc (Zn) content is one of the important breeding objectives, in addition to yield improvement under the irrigated and aerobic ecosystems. In view of developing genetic resources for aerobic conditions, line (L) × tester (T) analysis was conducted with four restorers, four CMS lines and 16 hybrids. Both hybrids and parental lines were evaluated in irrigated and aerobic field conditions for grain yield, grain Fe and Zn content. General Combining Ability (GCA) effects of parents and Specific Combining Ability (SCA) effects of hybrids were observed to be contrasting for the micronutrient content in both the growing environments. The grain Fe and Zn content for parental lines were negatively correlated with grain yield in both the contrasting growing conditions. However, hybrids exhibited positive correlation for grain Fe and Zn with grain yield under limited water conditions. The magnitude of SCA mean squares was much higher than GCA mean squares implying preponderance of dominance gene action and also role of complementary non-allelic gene(s) interaction of parents and suitability of hybrids to the aerobic system. The testers HHZ12-SAL8-Y1-SAL1 (T1) and HHZ17-Y16-Y3-Y2 (T2) were identified as good combiners for grain Zn content under irrigated and aerobic conditions respectively.

Rare Case Presentation of Leiomyosarcoma as IVC Thrombus.

Leiomyosarcoma (LMS) of vascular origin is uncommon. This leiomyosarcoma is seen occurring from the tunica media of major blood vessels. Leiomyosarcoma of venous origin is five times more common those of arterial origin. Most cases are presented in woman with a median age of 50 years [1]. We are presenting a case where histopathology was instrumental in making the diagnosis of LMS in the thrombus and confirmed by IHC. A 46-year old female presented with bilateral swelling of lower limbs and distention of abdomen. Her CT, MRI, and color Doppler were suggestive of IVC, hepatic, and renal vein thrombosis. Histopathology of thrombus revealed leiomyosarcoma and was confirmed by IHC. Conservative treatment was given and asked for a regular follow-up. This case report gives us an opportunity to think of a differential diagnosis in a patient presenting with IVC thrombus.

Prevalence of work related musculoskeletal disorders among physicians, surgeons and dentists: a comparative study.

BACKGROUND: Work related musculoskeletal disorders (MSDs) are one of the common occupational hazards among health care providers. AIM: The objective of this study was to evaluate MSDs in terms of perception of pain experienced by physicians, surgeons and dental surgeons during professional work. SUBJECTS AND METHODS: The study was conducted with 100 physicians practicing either modern or alternative medicine, 100 surgeons of various specialties and 100 dental surgeons. Self-reporting work related questionnaire on MSDs were distributed, including information on the location of MSD symptoms in the past 12 months and the pain experienced. RESULTS: Musculoskeletal pain was most prevalent among dentists 61% (61/100), followed by surgeons 37% (37/100) and physicians 20% (20/100). Nearly 15% of physicians (3/20), 40% (15/37) of Surgeons and 60% (35/61) of Dentists had MSD problems in more than one site. CONCLUSION: Within the limitations of the study, there is a higher prevalence of MSDs experienced by dental surgeons than physicians and surgeons. More research is needed on musculoskeletal problems with dental surgeons and other specialty doctors with an emphasis on a larger sample sizes and correlating other factors such as age and sex of the doctor, duration of practice, working hours per week, physical activity and working environment.

Role of glutathione-s-transferase and CYP1A1*2A polymorphisms in the therapy outcome of south Indian acute lymphoblastic leukemia patients.

BACKGROUND: Polymorphisms in the drug-metabolizing enzymes are found to be associated with the inter-individual variation in response to a particular drug. Glutathione S-transferases (GSTs) are involved in the metabolism of several anticancer drugs, including alkylating agents, anthracyclines, and cyclophosphamides. AIM: The present study is aimed to examine the association of GST and CYP1A1*2A polymorphisms in the susceptibility to acute lymphoblastic leukemia (ALL) and the prognostic significance. MATERIALS AND METHODS: A total of 92 immunophenotyped patients and 150 cord blood controls were genotyped by PCR for GSTM1 and GSTT1, RQ-PCR allelic discrimination assay for GSTP1 and PCR-RFLP for CYP1A1*2A polymorphism. RESULTS: We have previously reported the significant association of GSTM1 (null) and combined GSTP1 {(Ile/Val)/ (Val/Val)} /GSTM1 (null) genotype with the susceptibility to ALL. No significant association was observed with GSTT1 (P=0.75) and CYP1A1*2A (P=0.61 for +/- and P=0.86 for -/- respectively) in the susceptibility to ALL. Survival analysis was performed in 50 of the 92 patients who were followed for three years. Kaplan-Meier survival analysis for three years showed significant lower event-free survival in patients harboring GSTP1 (Ile/Val) and GSTP1 (Val/Val) (P=0.038 and 0.0001, respectively) genotype. Cox regression analysis revealed GSTP1 as an independent prognostic marker with 6-fold higher risk with Val/Val genotype (P=0.003). CONCLUSIONS: Our results show that GSTP1 (Ile/Val) polymorphism has a role in the susceptibility to ALL and also influence treatment outcome.

Role of GSTM1 (Present/Null) and GSTP1 (Ile105Val) polymorphisms in susceptibility to acute lymphoblastic leukemia among the South Indian population.

Acute lymphoblastic leukaemia (ALL) is the most common pediatric malignancy worldwide. The origin of this disease may be explained by a combination of genetic and environmental factors. Glutathione-s-transferases are a multi-gene family of enzymes involved in the detoxification of a wide variety of environmental carcinogens. A total of 92 immunophenotyped cases (below 25 years of age) and 150 cord blood controls were here analysed by PCR for GSTM1(Present/Null) and RQ-PCR allelic discrimination assay for GSTP1(Ile105Val). We found a significant increased risk for ALL with the GSTM1 null genotype (OR: 1.96, 95%CI=1.08-3.57), but no significant risk was found with the GSTP1 (Ile/Val) genotype (OR: 1.32, 95%CI = 0.74-2.37) and the GSTP1 Val/Val genotype (OR: 1.41, 95%CI=0.5-3.96) alone. Combined analysis of GSTM1 and GSTP1 showed significant higher risk associated with the GSTM1 (null/null) and GSTP1 [(Ile/Val)/ (Val/Val)] genotype (OR=2.78: 95%CI=1.16-6.69).