Delineating Genotype × Environment interactions towards durable resistance in mungbean against Cercospora leaf spot (Cercospora canescens) using GGE biplot

Cercospora leaf spot (Cercospora canescens) is a major fungal disease which impedes mungbean production worldwide. Presence of wider host range with existence of pathogenic variability creates intricacy towards host-pathogen dynamics. Moreover, environmental factors having crucial role in augmenting severity of this disease further complicate disease management. An attempt has been made for unfolding genotype x environment interactions towards identifying and validating durable resistant genotypes against cercospora leaf spot in multi-environment testing. Preliminary screening with 246 genotypes under artificial epiphytotic condition was conducted to extract out a subset of 22 mungbean genotypes for further evaluation in field testing across six environments consecutively for two years. GGE biplot analysis detected significant environmental influence towards genotypic response and confirmed the presence of non-crossover interaction with incoherent genotypic response, thus advocating the urgency for multi-location testing. GGE biplot aptly identified “LGG 460” and “COGG 912” as “ideal” and “desirable” genotypes, respectively having durable resistance and genetic homeostasis and thus suggested for their utilization in future resistance breeding programme in mungbean against cercospora leaf spot.     

Identification and characterization of SSRs in <Emphasis Type="Italic">Clarias batrachus</Emphasis> and their application in population study

Magur Clarias batrachus is an indigenous catfish, commonly found in India, Nepal, Bhutan and Bangladesh. Presently, the populations of magur have declined rapidly in their natural habitat mainly due to overexploitation and habitat degradation. Understanding the population genetic structure of the species has significance in improvement of stocks and in conservation of the species. In the present study, simple sequence repeat (SSR) markers were used to differentiate the populations of magur, collected from three geographic locations. For this, a total of 31,814 SSRs were mined from the de novo assembled pooled of whole genome sequence data of C. batrachus. A bioinformatics pipeline with stringent criteria was applied to analyze the data which resulted in selection of 30,142 microsatellite loci falling in the intergenic region. Out of the 25 loci selected for primer development, 16 loci were successfully amplified and 9 loci were found to be polymorphic in this species. The average observed as well as expected heterozygosity in the loci across different stocks varied from 0.652 to 0.688 and 0.864 to 0.873, respectively. These three populations were further segregated into two clusters based on the NJ genetic distance. The Lucknow population formed one cluster, while the Bhubaneswar and Kolkata populations constituted another cluster. A comparable finding was also deduced from the STRUCTURE analyses. The results revealed significant variation among the populations of C. batrachus under study.     

Internationale Landwirthschastliche Ausstellung zu Röln im Jahre 1865, unter dem Allerhöchsten Protektorate Sr. Rönigl. Roheit des Rronprinzen von Prenken

Ohne Zusammenfassung     

An avenue for replacement of chemical fertilization under rice-rice cropping pattern: Sustaining soil health and organic C pool via MSW-based vermicomposts

ABSTRACT

The impacts of Municipal solid wastes (MSW) vermicompost (VC) on soil-crop interface have rarely been studied. Hence, the influence of vermicompost on soil health and soil organic C (SOC) dynamics was assessed under intensive rice–rice cropping system. A 20–40% of the recommended N-fertilization was substituted by MSW-vermicompost for the crop. SOC storage, degree of humification, humic acid C, and fulvic acid C in soil gradually increased by 55–60% under NPK₆₀ + VC and NPK₈₀ + VC treatments in 2 years. The improvement in N-mineralization was spectacular in NPK₆₀ + VC (2.79 folds) and NPK₈₀ + VC (2.25 folds) treated soil. The carbon pool management index in soil was greatest under NPK₆₀ + VC (2.1) treatment followed by NPK₁₀₀ + VC (1.96) and NPK₈₀ + VC (1.87) treatments. Moreover, the crop biomass and grain yield increased under VC treatments. The correlation and regression statistics revealed that rice production was enhanced due to improvement of SOC pool and humified carbon fractions in soil. Finally, we recorded highest benefit-cost ratio under NPK₆₀ + VC (benefit/cost 5.55) followed by NPK₈₀ + VC (benefit/cost 5.44). The study indicated that MSW-vermicompost sustained soil microbial health and SOC balance, which significantly correlated with rice production.     

High frequency shoot proliferation from cotyledonary node of <Emphasis Type="Italic">Lawsonia inermis</Emphasis> L. and validation of their molecular finger printing

An efficient and reproducible protocol for in vitro plant regeneration was developed for Lawsonia inermis L. using cotyledonary node explant derived from axenic seedlings. Highest shoot proliferation frequency (ca 96.6%) was achieved on Murashige and Skoog’s, 1962 (MS) basal medium supplemented with 8.88 μM 6-Benzyladenine (BA) + 2.68 μM Napthalene acetic acid (NAA). Up-scaling of shoots was carried out using in vitro nodes on MS medium supplemented with 4.44 μM BA. So overall, an average of 238 shoots was produced at 75 days. Of the four different forms of cotyledonary node explants evaluated, highest shoot multiplication was observed in cotyledonary node explant with two whole cotyledons. In vitro regenerated shoots were best rooted (ca 34.3 roots / shoot) on ½ MS medium devoid of any growth regulator. The plantlets were successfully acclimated in sand:soil:: 1:1and established in the garden soil. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analysis revealed a homogeneous amplification profile for all micropropagated plants validating the genetic fidelity of the in vitro-regenerated plants and supporting the regeneration protocol for economic commercial exploitation.     

Genetic Diversity Analysis of Rice Germplasm in Tripura State of Northeast India Using Drought and Blast Linked Markers

We genotyped 74 rice germplasms including Tripura's local landraces, improved varieties, cultivars and breeding lines and other rice varieties using molecular markers for genetic diversity, drought QTLs, and blast resistance genes. The number of alleles per locus ranged from 2 to 5 with an average of 2.9. The polymorphic information content value per locus ranged from 0.059 (RM537) to 0.755 (RM252) with an average of 0.475. Cluster analysis based on 30 simple sequence repeat markers revealed 5 clusters and also indicated the presence of variability within the rice accessions. The drought QTL qDTY2.1 was found in 56.0% of germplasms and qDTY1.1 was detected in only 6.8% of the germplasms. Out of seven rice blast resistance genes screened, only two rice varieties, RCPL-1-82 and Buh Vubuk (Lubuk), were positive for four blast resistance genes while only Releng possessed two blast resistance genes. Among 74 rice germplasms, only three accessions, Releng, RCPL1-82 and Buh Vubuk (Lubuk), possessed both drought-related QTLs and blast resistance genes. Overall, the 74 indigenous rice genotypes showed low level of genetic diversity, which is in contrast to high level of genetic diversity among rice varieties in northeast India, where highlights the good farming practice, conservation of germplasms and the limitation of molecular markers employed in this study. The presence of both drought related QTLs and blast resistance genes in some of the germplasms can be useful in future breeding programmes.     

STUDIES ON THE HEIGHT/WEIGHT RELATIONSHIP IN DESERT RANGE GRASSES OF INDIA

Studies on height/weight relationship of the key grass species of Western Rajasthan ranges, India, were undertaken so as to form concepts which will guide the assessnient of the extent of their utilization by the livestock. Regression studies of the data obtained indicated that the relationship between the percentage of height clipped and the percentage of weight removed is quadratic. A graph has been drawn for each of the 5 species to relate the percentage of height removed with the percentage of weight utilized. The studies have shown that the weight distribution in respect of height is different in different species.     

Indicators of soil quality and crop productivity assessment at a long-term experiment site in the lower Indo-Gangetic plains

Deterioration of soil quality under resource-intensive modern agriculture in the face of global climate change poses a huge risk to food security. Because of the complex nature, estimators of soil quality often rely upon a limited set of soil attributes, along with statistical data reduction techniques, for developing quality indices, whilst overlooking biological aspects and regional climatic variability. This study screened the most suitable soil quality indexing approaches for a rice-oilseed-based cropping system in the lower Indo-Gangetic plains (IGP). For this, surface soil samples (0–15 cm) were collected from an ongoing long-term fertilizer experiment with a rice-mustard-sesame cropping system in the IGP. The following treatments were assessed for their effect on soil quality: T₁-control, T₂-NPK (recommended NPK doses), T₃-NPKG (NPK + in situ green manuring), T₄-NPKGB (NPK + in situ green manuring + biofertilizer) and T₅-NPKF (NPK + farm yard manure FYM). We found that total organic carbon (TOC), β-glucosidase, CaCl₂ extractable S, alkaline KMnO₄ oxidizable N, activity of urease, amidase enzyme and mean weight diameter (MWD) were sensitive key indicators of soil quality. The NPKF treatment maintained the highest soil quality status (0.80–0.91), both under productivity and environmental protection goals, owing to the availability of decomposable carbon. Regression analysis showed a better agreement of equivalent rice yield with expert opinion (EO; R² = 0.89) than principal component analysis (PCA; R² = 0.76). Finally, we found that the expert opinion approach with the nonlinear scoring function was the best tool for soil quality assessment of the region.