Effect of Various Sowing Dates on the Management of Wilt of Guar (\u3cem\u3eCyamopsis tetragonaloba\u3c/em\u3e L.)

Cluster bean [Cyamopsis tetragonoloba (L.) Taub.], commonly known as guar, is a member of Leguminosae (Fabaceae) family. It is a short duration, drought resistant, low investment and high return cash crop. In Punjab, it is one of the important legume crop grown on about 9514 ha with production of 0.24 million ton (Anonymous, 2013). It can be grown in mixture with bajra and jowar but pure crop of guar supplies highest tonnage of palatable nutritious green fodder for longer duration without much deterioration in quality with the age of the crop. It is rich in nutrients with crude protein content and total digestible nutrients on dry matter basis of 18.1 and 60.0 per cent respectively. Besides fodder, it can also be grown for grain, green manure, cover crop and for vegetable purposes. Although, cluster bean being a hardy crop is very sensitive to the biotic and abiotic stresses. The crop has succumbed to number of diseases caused by fungi, bacteria and viruses. Of the all diseases, wilt of guar (Fusarium caeruleum) is a very serious disease. It causes heavy losses in summer sown crop and damage is visible on young plants. Attacks of the Fusarium wilt pathogen can destroy the crop completely. Modification of the soil environment by altering sowing dates and introduction of resistant genotypes can be effective control for Fusarium solani EGY 1causing wilt in guar

Management of Foliar Diseases of Forage Sorghum

Sorghum (Sorghum bicolor L. Moench.) is an important food, feed, fodder and fuel crop grown in India. It forms staple food for poor class of people living in the dry tracts of the country. The crop is mostly grown during Kharif and Rabi seasons in Maharashtra, Karnataka, Andhra Pradesh and Madhya Pradesh states. It is also very popular as green forage in most parts of north India and nearly 2.5 million ha area is planted during kharif. In summer, under irrigated conditions, multicut sorghum is very popular. Forage sorghum is characterized by quick growth, high biomass accumulation, dry matter content and wide adaptability beside drought withstanding ability. It is also suitable for silage and hay making. The losses caused by diseases were estimated to be 12% (Frederiksen, 1986). With the change in climate, cropping pattern and with the introduction of high yielding varieties and hybrids of sorghum for cultivation, the disease scenario has also changed. Forage sorghum is suffered by charcoal rot, downy mildew, foliar diseases like zonate leaf spot, anthracnose and leaf blight. The disease is serious both in grain as well as fodder sorghum as it reduces yield and quality of fodder considerably. Disease resistance, cultural, biological and fungicides have been utilized to manage sorghum diseases (Frederiksen, 2000). The present study was undertaken to find out suitable management practice for foliar diseases of forage sorghum

Investigation of optimum conditions for the growth of Fusarium solani EGY1 causing root rot of guar (Cyamopsis tetragonoloba L.)

Guar gum (Galactomannan) is extracted from Guar (Cluster bean), which is extensively used in petroleum, food and pharmaceutical industry. Root rot of guaris caused by Fusarium solani EGY1 under Punjab, having sub-tropical climatic conditions. This study was undertaken to evaluate different culture media, grain substrates (sorghum, maize, cowpea, guar and pearl millet), temperatures (20, 25, 30, 35oC), pH levels (5.0, 6.0, 7.0, 8.0), light and darkness for the identification of optimum conditions for the growth and sporulation of the fungus. Czapek’s dox media was found to be best for growth (84.65 mm) and sporulation (1.8 x 104microconidia and 3.0 x 104 macro conidia) of fungus. For mass multiplication of the fungus, sorghum grains proved to be the best substrate. The fungus showed maximum radial growth at temperature of 25oC (84.36 mm) and pH of 6.0 (84.43 mm) whereas sporulation was highest at 30oC (2.0 x 104 microconidia and 3.2 x 104 macroconidia) and pH of 8.0 (1.8 x 104 microconidia and 3.1 x 104 macroconidia) respectively. Continuous light favoured radial growth (84.62 mm) whereas sporulation (1.8 x 104 microconidia and 3.1 x 104 macroconidia) was favoured by darkness

Identification of novel resistant sources for ascochyta blight (Ascochyta rabiei) in chickpea

Chickpea (Cicer arietinum L.) is the second largest pulse crop grown worldwide and ascochyta blight caused by Ascochyta rabiei (Pass.) Labr. is the most devastating disease of the crop in all chickpea growing areas across the continents. The pathogen A. rabiei is highly variable. The resistant sources available are not sufficient and new sources needs to be identified from time to time as resistance breakdown in existing chickpea varieties is very frequent due to fast evolution of new pathotypes of the pathogen. Therefore, this work was undertaken to evaluate the existing chickpea germplasm diversity conserved in Indian National Genebank against the disease under artificial epiphytotic conditions. An artificial standard inoculation procedure was followed for uniform spread of the pathogen. During the last five winter seasons from 2014–15 to 2018–19, a total of 1,970 accessions have been screened against the disease and promising accessions were identified and validated. Screening has resulted in identification of some promising chickpea accessions such as IC275447, IC117744, EC267301, IC248147 and EC220109 which have shown the disease resistance (disease severity score �3) in multiple seasons and locations. Promising accessions can serve as the potential donors in chickpea improvement programs. The frequency of resistant and moderately resistant type accessions was comparatively higher in accessions originated from Southwest Asian countries particularly Iran and Syria than the accessions originated from Indian sub-continent. Further large scale screening of chickpea germplasm originated from Southwest Asia may result in identifying new resistant sources for the disease

Novel Genomic Regions Linked to Ascochyta Blight Resistance in Two Differentially Resistant Cultivars of Chickpea

Ascochyta blight (AB), caused by the fungal pathogen Ascochyta rabiei, is a devastating foliar disease of chickpea (Cicer arietinum L.). The genotyping-by-sequencing (GBS)-based approach was deployed for mapping QTLs associated with AB resistance in chickpea in two recombinant inbred line populations derived from two crosses (AB3279 derived from ILC 1929 × ILC 3279 and AB482 derived from ILC 1929 × ILC 482) and tested in six different environments. Twenty-one different genomic regions linked to AB resistance were identified in regions CalG02 and CalG04 in both populations AB3279 and AB482. These regions contain 1,118 SNPs significantly associated with AB resistance (p ≤ 0.001), which explained 11.2–39.3% of the phenotypic variation (PVE). Nine of the AB resistance-associated genomic regions were newly detected in this study, while twelve regions were known from previous AB studies. The proposed physical map narrows down AB resistance to consistent genomic regions identified across different environments. Gene ontology (GO) assigned these QTLs to 319 genes, many of which were associated with stress and disease resistance, and with most important genes belonging to resistance gene families such as leucine-rich repeat (LRR) and transcription factor families. Our results indicate that the flowering-associated gene GIGANTEA is a possible key factor in AB resistance in chickpea. The results have identified AB resistance-associated regions on the physical genetic map of chickpea and allowed for the identification of associated markers that will help in breeding of AB-resistant varieties

Highly efficient and stable Ra2LaNbO6 double perovskite for energy conversion device applications

Using first-principles calculations, in this piece of work, authors have investigated the physical properties of Ra2LaNbO6 double perovskite by employing the linearized augmented plane wave (LAPW) method. Structural and electronic properties are determined by using LDA, GGA (WC and PBE), LDA + mBJ, and GGA + mBJ potentials. We have found that Ra2LaNbO6 is an indirect band gap (Eg = 2.4 eV) semiconductor. Its elastic and thermodynamic parameters demonstrate its stability. Its optical study indicates that this material opens the door to its applications in optical devices such as photodetectors, solar cells, superlenses, optical fibers, filters, electromagnetic shielding devices, photovoltaic devices, etc. This material is very good for its practical implementation in thermoelectric devices as both p- and n-type material and extends the interest of experimentalists for further investigations. Thus, Ra2LaNbO6 is found thermodynamically stable and identified as a potential candidate for photovoltaic and thermoelectric devices

Malaria diagnosis by PCR revealed differential distribution of mono and mixed species infections by plasmodium falciparum and p. vivax in India

Malaria is a vector-borne infectious disease, caused by five different species of the genus Plasmodium, and is endemic to many tropical and sub-tropical countries of the globe. At present, malaria diagnosis at the primary health care level in India is conducted by either microscopy or rapid diagnostic test (RDT). In recent years, molecular diagnosis (by PCR assay), has emerged as the most sensitive method for malaria diagnosis. India is highly endemic to malaria and shoulders the burden of two major malaria parasites, Plasmodium falciparum and P. vivax. Previous studies using PCR diagnostic assay had unraveled several interesting facts on distribution of malaria parasites in India. However, these studies had several limitations from small sample size to limited geographical areas of sampling. In order to mitigate these limitations, we have collected finger-prick blood samples from 2,333 malaria symptomatic individuals in nine states from 11 geographic locations, covering almost the entire malaria endemic regions of India and performed all the three diagnostic tests (microscopy, RDT and PCR assay) and also have conducted comparative assessment on the performance of the three diagnostic tests. Since PCR assay turned out to be highly sensitive (827 malaria positive cases) among the three types of tests, we have utilized data from PCR diagnostic assay for analyses and inferences. The results indicate varied distributional prevalence of P. vivax and P. falciparum according to locations in India, and also the mixed species infection due to these two species. The proportion of P. falciparum to P. vivax was found to be 49:51, and percentage of mixed species infections due to these two parasites was found to be 13% of total infections. Considering India is set for malaria elimination by 2030, the present malaria epidemiological information is of high importance

Identification of novel resistant sources for ascochyta blight (Ascochyta rabiei) in chickpea.

Chickpea (Cicer arietinum L.) is the second largest pulse crop grown worldwide and ascochyta blight caused by Ascochyta rabiei (Pass.) Labr. is the most devastating disease of the crop in all chickpea growing areas across the continents. The pathogen A. rabiei is highly variable. The resistant sources available are not sufficient and new sources needs to be identified from time to time as resistance breakdown in existing chickpea varieties is very frequent due to fast evolution of new pathotypes of the pathogen. Therefore, this work was undertaken to evaluate the existing chickpea germplasm diversity conserved in Indian National Genebank against the disease under artificial epiphytotic conditions. An artificial standard inoculation procedure was followed for uniform spread of the pathogen. During the last five winter seasons from 2014-15 to 2018-19, a total of 1,970 accessions have been screened against the disease and promising accessions were identified and validated. Screening has resulted in identification of some promising chickpea accessions such as IC275447, IC117744, EC267301, IC248147 and EC220109 which have shown the disease resistance (disease severity score ≤3) in multiple seasons and locations. Promising accessions can serve as the potential donors in chickpea improvement programs. The frequency of resistant and moderately resistant type accessions was comparatively higher in accessions originated from Southwest Asian countries particularly Iran and Syria than the accessions originated from Indian sub-continent. Further large scale screening of chickpea germplasm originated from Southwest Asia may result in identifying new resistant sources for the disease

Multi-location testing of a global collection of elite chickpea genotypes to identify stable sources of resistance to Ascochyta blight

Ascochyta blight (AB) of chickpea (Cicer arietinum L.) caused by Ascochyta rabiei (Pass.) Lab. is the most devastating disease that limits the productivity and production of chickpea in the world. The lack of high levels of stable sources of resistance makes chickpea production a risky business. The search for durable resistance genotypes and differentials to monitor shifts in pathogen populations are becoming a pressing research agenda. There is a need to understand the evolution of pathogen virulence and the number of resistant genes available in chickpea germplasm. Therefore, this research aimed to evaluate the global Ascochyta blight reference set in chickpea (GABRSC), which is expected to carry some of the resistant genes to AB has been identified in many countries. The GABRSC set (200 diverse genotypes) was evaluated in six geographic locations where AB is a major disease. The testing sites were Kafarshakhna (Lebanon), Merchouch (Morocco), Alem Tena (Ethiopia), Punjab University (India), Beja (Tunisia), and Gaziantep University (Turkey). The genotypes were planted following Alpha Lattice design in two replications in the 2021–22 cropping season. Disease severity was rated using a 1–9 rating scale. The REML analysis showed significant differences among genotypes (G), environments (E), and G x E interactions showing the possibility of different pathogen populations in different locations. The GGE biplot analyses showed that all environments were positively related. A total of 11 genotypes (S160454, SE26IN, S0110227, M 2635, S0110075, S160353, S0110028, 0110088, S0110195, S0110211, and S160483) were consistent in their resistance across sites with an average rating of ≤ 4. On the other hand, genotypes showed crossover interactions across locations. For example, PBA HatTrick was resistant in Ethiopia (but susceptible in Lebanon and FLIP84-48C was resistant in India but susceptible in Lebanon. This study will help us to understand the relationship between the host and pathogen and to design new AB differential sets. However, the resistant genotypes across locations identified in the present study would be useful in breeding programs

Map of India showing malaria sample collection site.

<p>Each site is represented by a pie-chart three different kinds of infection (two types of mono infections and a mixed species infection due to <i>P</i>. <i>falciparum</i> and <i>P</i>. <i>vivax</i>). To be noted here that locations in all the four directions (peripheral populations) (north, east, west and south) are majorly dominated by <i>P</i>. <i>vivax</i>, but in northeast, south-west and middle Indian locations <i>P</i>. <i>falciparum</i> was found to be in higher abundance than <i>P</i>. <i>vivax</i>. Mixed parasitic infections majorly are restricted to middle of India.</p