Pusa Basmati Research Articles

Application of additional dose of N could sustain rice yield and maintain plant nitrogen under elevated ozone (O3) and carbon dioxide (CO2) condition

IntroductionGlobal food security is challenged by the increasing levels of air pollutants like ozone (O3) through their impacts on crop productivity. The present study was conducted to quantify the interactive effect of elevated ozone (O3) and carbon dioxide (CO2), on different rice varieties in northern India.MethodsAn experiment was conducted in Genetic H field, Environment science, IARI for two consecutive years (2020 and 2021) during the kharif season, to quantify the impact of elevated O3 and CO2 interaction on productivity, and plant N in three rice varieties (Pusa basmati 1121, Nagina 22, IR64 Drt1) under different nitrogen (N) management practices. Rice crop was grown in Free Air Ozone-Carbon dioxide Enrichment rings (FAOCE) rings with two levels of O3 (elevated 60 ±10ppb and ambient) and two levels of CO2 (elevated, 550±25 ppm and ambient) concentration and their interaction with two N fertilizer treatments i.e., 100% RDN (recommended dose of N) and 125% RDN.Results and discussionElevated O3 significantly decreased physiological parameters like photosynthesis rate, stomatal conductance and transpiration rate of the crop. Grain yield reduced by 7.2-7.5%, in Pusa Basmati 1121 and from 6.9-9% in IR64 Drt1 varieties in elevated O3 treatment as compared to ambient treatment. Yield reduction in Nagina 22 variety was not significant in elevated O3 treatment. Elevated CO2 concentration of 550 ppm was able to fully compensate the yield loss in Nagina 22 variety and partially compensate (3.9-8.0%) in Pusa Basmati 1121 and IR64 Drt1 varieties. Grain N concentration in rice varieties decreased by 10.8-14.7% during first year and by 7.8-20.6% during second year in elevated O3 plus CO2 interaction treatment than ambient. Grain N uptake also decreased (13.2-17.1% in first year and 4.5-22.8% in second year) in elevated O3 plus CO2 interaction treatment as compared to ambient. Application of additional 25% of recommended dose of N improved grain N concentration, grain N uptake as well as available N of soil as compared to 100% RDN treatment in elevated O3 plus CO2 interaction treatment. Additional 25% N dose could help in sustaining rice productivity and quality under elevated O3 and CO2 condition.

Sodium alumino silicate (SAS) neem nanocomposite – A novel seed storage tool against toxigenic Aspergillus flavus causing deterimental effects on seeds health and quality of rice

Infection of rice grains in the field during harvest and storage by Aspergillus flavus, a toxigenic mold causes significant losses to market acceptability of seeds due to its detrimental effects on seed health and quality parameters. Production of aflatoxin by A. flavus interferes with physiological factors affecting the quality of seeds during storage in addition to nutritional losses to the grains. Chemical seed treatments are generally not recommended during storage due to their adverse effects on seed germination and vigor. Leaves of the neem tree (Azadirachta indica) are well known for antifungal properties against phytopathogenic fungi such as A. flavus. The paper presents the effect of neem leaf extract adsorbed onto sodium alumino-silicate (SAS) nanoparticles against A. flavus in rice seeds during storage. SAS-Neem nanocomposite, a novel unexplored seed storage material against toxigenic A. flavus, was synthesized for augmented antitoxin and seed invigorating potential. The nanocomposite was characterized using an array of microscopic and spectroscopic methods to evaluate the adsorption of neem leaf extract components on SAS nanoparticles. The antifungal mechanism of the nanocomposite was evaluated via scanning electron microscope, phase contrast, and fluorescence microscopy. The toxin analysis of pathogen-inoculated seeds was carried out at monthly intervals for 6 months during storage of two rice varieties, i.e. PR114 and Pusa-Basmati 1121. The results indicated that the nSAS-Neem composite used as seed coating material maintained significantly higher seed germination (86.23 and 81.49%) and minimized seed rot (6.70 and 5.30%, respectively) in the two varieties under study than the control after 6 months of storage. There was a notable decrease in toxin concentration from 20.58 to 11.19 μg/kg and 19.16 to 12.58 μg/kg in seeds of the two varieties i.e. PR114 and Pusa Basmati 1121, respectively. The nano-composite proved effective against toxigenic A. flavus during seed storage of rice without compromising the seed quality parameters.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Evaluation of Sheath Blight Resistance in Diverse Rice Varieties Under Artificial Inoculation and Field Conditions

Rice (Oryza sativa L.) a vital food crop for nearly half of the global population, facing significant threats from various biotic and abiotic stresses. Among biotic stresses, diseases pose the most common challenge. Sheath blight, caused by soil-borne fungal pathogen Rhizoctonia Solani Kühn (R. solani), is a major concern, leading to substantial damage to rice and cereal crops worldwide. This study evaluated sheath blight resistance across diverse rice varieties, including short grain, long grain, aromatic, hybrid, and wild types, under both artificial inoculation and field conditions. Ten host plant species were assessed for resistance to sheath blight caused by Rhizoctonia Solani, using physiological screening one-week post-inoculation. The highly virulent R. solani isolate (AG-1 IA anastomosis group) was cultured on PDA media, covering the entire plate 3 to 5 days. Screening of cultivated rice varieties, was conducted using field conditions and humidified chamber methods, with results confirmed through molecular characterization. Among the ten cultivated rice varieties, Arize 6444 and Dhanya 748 exhibited the lowest disease index, classifying them as moderately resistant. In contrast, Kalanamak and Pusa Basmati were highly susceptible, displaying high disease indices. Among wild rice accessions, Oryza rufipogon showed a disease index of five or less. Visual ratings indicated the highest susceptibility in Kalanamak, followed by Pusa Basmati and Swarna sub-1, while the lowest visual ratings were observed in wild rice accessions Oryza australiensis and Oryza rufipogon across all tested hosts. The findings underscore the importance of identifying resistant rice varieties to manage sheath blight effectively. The moderately resistant cultivars and wild rice accessions identified in this study offer valuable genetic resources for breeding programs aimed at enhancing sheath blight resistance in rice.

Comparative Analysis of Peroxidase and Catalase Isoenzymes via Native-PAGE Electrophoresis and SDS-PAGE Profiling of Leaf Proteins in Rice Varieties under Infection Stress

Rice (Oryza sativa L.) is a staple food for over half of the world's population. However, rice productivity is significantly hindered by various diseases, including sheath blight caused by Rhizoctonia solani. This study aims to evaluate the resistance of different rice varieties and wild rice accessions to sheath blight and to analyze the biochemical responses, specifically peroxidase and catalase activities, under infection stress. The results revealed that Kalanamak and Pusa Basmati were highly susceptible, with high disease indices and visual ratings. Conversely, wild rice accessions such as O. rufipogon and O. australiensis exhibited lower disease indices, indicating moderate resistance. Peroxidase activity varied significantly among the rice leaves, ranging from 148.83 to 182.44 mg/g fresh weight/min. Dhanya 748 showed the highest peroxidase activity, followed by O. australiensis and O. rufipogon. Native-PAGE electrophoresis of peroxidase isoenzymes demonstrated high-intensity bands in O. rufipogon, BPT 5204, and Swarna Sub-1, while minimal or no bands were observed in other genotypes, indicating varying levels of peroxidase activity. Catalase activity also showed significant variation, ranging from 138.18 to 152.14 mg/g fresh weight/min. BPT-5204 exhibited the highest catalase activity, followed by O. australiensis and Pusa Basmati. Isoenzyme analysis via Native-PAGE revealed high-intensity catalase bands in O. australiensis, Dhanya 748, NDR 118, and Pusa Basmati, while no bands were observed in O. rufipogon, CSR 13, Arize 6444, and Swarna Sub-1. SDS-PAGE analysis of leaf proteins showed variability in banding patterns. Non-infected leaves of Swarna Sub-1, Arize 6444, Kalanamak, and Pusa Basmati had minimal bands, while O. australiensis and Dhanya 748 showed maximum bands. Infected leaves of CSR 13, NDR 118, Arize 6444, Kalanamak, Dhanya 748, and Pusa Basmati had minimal bands, whereas O. australiensis exhibited maximum bands. Overall, the study highlights the potential of wild rice species in enhancing disease resistance and provides insights into the biochemical responses of rice varieties under pathogen stress.

Influence of microbial consortia mediated in-situ rice straw management options on yield, economics and energetics in rice-wheat cropping system

A field experiment was carried out during rainy and winter seasons of 2019–20 and 2020–21 at ICAR-IARI, New Delhi to study the effect of crop establishment methods and microbial consortia (Pusa decomposer) mediated in-situ rice straw management options on yield, economics and energetics of rice (Oryza sativa L) (cv. Pusa Basmati 1509) and wheat (Triticum aestivum L.) (cv. HD 2967). The experiment was laid out in split-plot design with three replications. The main plot consisted of two treatments viz., aerobic rice (AR) and conventional transplanted (CT) rice in wet season and seven sub-plot treatments viz. clean cultivation (removal of paddy straw), paddy straw incorporation (PSI), paddy straw mulching (PSM), PSI + Pusa decomposer (PD), PSM + PD, PSI + urea @ 20 kg/ha, PSI + PD + urea @ 10 kg/ha in dry season. In rice, results showed that grain yield (4.23 and 4.42 t/ha), net return (`69,470 and `71,682/ha) and energy output (157361 and 160950 MJ/ha) were significantly superior in CT rice than AR in main plots during both the years of experiment. However, sub-plot treatments showed a non-significant difference on these parameters. In wheat, among in-situ rice straw management options, paddy straw incorporation+ Pusa decomposer + urea @ 10 kg/ha treatment significantly resulted in higher grain yield (4.86 and 4.92 t/ha), net return (`62697 and `64801 /ha) and energy output (174951 and 176730 MJ/ha) compared to other treatments and control (clean cultivation). However, in main plots, statistically similar results were obtained with AR-wheat and CT-wheat. Thus, conventional rice transplanting resulted in significantly higher productivity and profitability over aerobic rice, however, AR consumed less energy (18.95%) and water (31.73%). Whereas, paddy straw incorporation+ Pusa decomposer + Urea @ 10 kg/ha was found effective in-situ rice management options with higher productivity and energy output compared to control.

Differential preference of grain of landrace and commercial rice genotypes to Sitophilus oryzae (L.) (Coleoptera: Curculionidae) attack

The rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), is one of the most damaging pests to stored cereal grains worldwide. The current study aimed to clarify the relationship between S. oryzae development and the governing physicochemical grain properties. Laboratory experiments were conducted to determine the grain preference of various landrace and commercial rice genotypes to rice weevil. S. oryzae, findings divulged the low rates of adult emergence, low rates of grain consumption and high rates of mortality in the grain of rice varieties, HUR-3022 and Nagina-22. Conversely, S. oryzae adult emergence and grain consumption were found to be high in the grain of Swarna, Sathi, and Pusa basmati-1. Interestingly, the morphological and biochemical composition of the grain was the most important factor in determining resistant or preferred rice varieties to S. oryzae. Among the various physical characteristics investigated, grain hardness was found to have a significant and negative correlation with alive insect, grain weight loss, and preference index. On the other hand, protein and other biochemical grain characteristics were found to have a positive correlation with insect emergence, weight loss, and preference index. In particular, amylose (a key grain component) was found to have a negative correlation with weight loss and insect emergence. The findings of this study suggest that screening of different rice genotypes, for determining grain preference, may be a more viable option to minimize the grain losses during storage caused by S. oryzae. Moreover, the findings of present study could also help to formulate the breeding programs aimed at developing cultivars resistant to this notorious pest.

THE EFFECT OF COVID-19 ON THE VALUE CHAIN OF PADDY AND CARROT VARIETY OF IARI

The arrival of COVID-19 was no less than any apocalypse for the global economy. The growth of global GDP spiralled down to a very low point. The condition in India was no exception to it. Almost all the sectors of the economy were severely affected. Notwithstanding this, agriculture emerged as a bright spot in the dark horizon. Even though the growth rate was positive, there were serious impediments in the commodity value chain and agricultural marketing. Paucity in input supply, restriction in movement, closure of market, reduced demand of food products brought challenges that existed never before. In this backdrop, a study was conducted to find out the effects of COVID-19 on the value chain and marketing of Paddy Commercial variety Pusa Basmati 1121 and Carrot Commercial variety Pusa Rudhira. The research design was ex-post facto in nature and a total number of 160 farmers and 50 stakeholders including exporters, commission agents, wholesalers, and millers were consulted for the study. The locale of the study was Soodhna (U.P), Sangohi (Haryana), Khwajpur (U.P) and Nizampur (New Delhi). From extant review of literature, pilot study and discussion with experts, several constraints faced by the value chain stakeholders were identified and rank ordered using Rank Based Quotient Method (R.B.Q). Results showed that in case of farmers "difficulty in getting buyer, price fluctuation and wastage" were among the top constraints, and for stakeholders such as millers, wholesalers and retailers, "unavailability of labour and price fluctuations" were the causes of concern. Moreover, for exporters "hike in freight charges" was the most severe constraint. The findings of the study could highlight the vulnerable areas in the commodity value chain which ought to get due attention in policy making and better preparedness for future events of similar nature.

Zinc uptake in rice (Oryza sativa)-wheat (Triticum aestivum) cropping system under the influence of microbial consortia (Pusa decomposer) mediatedin situ rice straw management options

A field experiment was conducted during the rainy (kharif) and winter (rabi) seasons of 2019–20 and 2020–21 at research farm of ICAR-Indian Agricultural Research Institute, New Delhi to study the effect of various crop establishment methods and microbial consortia (Pusa decomposer) mediated in situ rice straw management options on zinc (Zn) concentration and uptake in rice (Oryza sativa L.) (cv. Pusa Basmati 1509) and wheat (Triticum aestivum L.) (cv. HD 2967). The experiment was laid out in split-plot design (SPD) with 3 replications having 2 main plot (main factor) treatments, viz. aerobic rice (AR); and conventional transplanted (CT) rice in wet season; and 7 sub- plot (sub-factor) treatments, viz. Clean cultivation (removal of paddy straw); Paddy straw incorporation (PSI); Paddy straw mulching (PSM); PSI + Pusa decomposer (PD); PSM + PD; PSI + urea @20 kg/ha; and PSI + PD + urea @10 kg/ha in dry season. Findings showed that, in rice the zinc concentration (18.51 and 20.30 mg/kg in grain; 57.02 and 57.81 mg/kg in straw) and uptake (78.38 and 89.81 g/ha in grain; 427.1 and 434.6 g/ha in straw) were significantly superior in CT rice than AR in main plots during both the years of experiments. However, sub-plot treatments were non-significant in the zinc concentration and uptake. In wheat, among in situ rice straw management options (sub- plots), paddy straw incorporation + Pusa decomposer + Urea @10 kg/ha treatment significantly resulted in higher Zn concentration (38.08 and 39.03 mg/kg in grain; 28.24 and 29.01 mg/kg in straw) and uptake (185.0 and 191.9 g/ha in grain; 234.2 and 242.6 g/ha in straw) compared to other treatments and control (clean cultivation). The principal component analysis revealed that Zn uptake positively correlated with straw and grain yields in rice and wheat. Thus, the same treatment was found to be a better option for higher Zn concentration and uptake in the rice-wheat cropping system.

Seed Health Testing of Recombinant Inbred Lines Derived from Cross between Kalonunia and Pusa Basmati 1637

Seed Health Testing of Recombinant Inbred Lines Derived from Cross between Kalonunia and Pusa Basmati 1637

Overexpression of OsTIP1;2 confers arsenite tolerance in rice and reduces root-to-shoot translocation of arsenic

Tonoplast Intrinsic Proteins (TIPs) are vital in transporting water and solutes across vacuolar membrane. The role of TIPs in the arsenic stress response is largely undefined. Rice shows sensitivity to the arsenite [As[III]] stress and its accumulation at high concentrations in grains poses severe health hazards. In this study, functional characterization of OsTIP1;2 from Oryza sativa indica cultivar Pusa Basmati-1 (PB-1) was done under the As[III] stress. Overexpression of OsTIP1;2 in PB-1 rice conferred tolerance to As[III] treatment measured in terms of enhanced shoot growth, biomass, and shoot/root ratio of overexpression (OE) lines compared to the wild-type (WT) plants. Moreover, seed priming with the IRW100 yeast cells (deficient in vacuolar membrane As[III] transporter YCF1) expressing OsTIP1;2 further increased As[III] stress tolerance of both WT and OE plants. The dithizone assay showed that WT plants accumulated high arsenic in shoots, while OE lines accumulated more arsenic in roots than shoots thereby limiting the translocation of arsenic to shoot. The activity of enzymatic and non-enzymatic antioxidants also increased in the OE lines on exposure to As[III]. The tissue-specific localization showed OsTIP1;2 promoter activity in root and root hairs, indicating its possible root-specific function. After As[III] treatment in hydroponic medium, the arsenic translocation factor (TF) for WT was around 0.8, while that of OE lines was around 0.2. Moreover, the arsenic content in the grains of OE lines reduced significantly compared to WT plants.

Cyanobacteria Based Nanoformulation of Biogenic CuO Nanoparticles for Plant Growth Promotion of Rice Under Hydroponics Conditions.

Synthesizing nanoparticles through a green synthesis approach is common nowadays. Cyanobacteria have attained great importance in the field of biosynthesis of nanoparticles as there is no use of toxic chemicals as reducing or capping agents for the synthesis of metal oxide nanoparticles. Micronutrient-based nano-formulations have become a topic of great interest in recent times due to their various advantageous properties and applications in agriculture. The current study aims to exploit the potential cyanobacterial strains isolated from different locations such as freshwater and soil ecosystems. The potential cyanobacterial isolates were screened based on their multiple plant growth promoting (PGP) attributes such as Indol acetic acid (IAA) production, siderophores, and phosphate solubilization. After the screening of cyanobacteria based on multiple PGP activities, the cyanobacterial strain was identified at the species level as Pseudanabaena foetida RJ1, based on microscopy and molecular characterization using 16S rRNA gene sequencing. The cyanobacterial biomass extract and cell-free extracts are utilized for the synthesis of CuO micronutrient Nanoparticles (NPs). The cyanobacterial strain Pseudanabaena foetida RJ1 possesses plant growth-promoting (PGP) attributes that provide reduction and capping for CuO NPs. The synthesized NPs were characterized and subjected to make a nano-formulation, utilizing the cyanobacteria-mediated CuO NPs along with low-cost zeolite as an adsorbent. The application of cyanobacterial biomass extract and cell-free extract provided an excellent comparative aspect in terms of micronutrient NP synthesis. The NPs in the form of formulations were applied to germinated paddy seeds (Pusa Basmati -1509) with varying concentrations (5, 10, 15mg/l). Effects of cyanobacteria based CuO NPs on hydroponically grown paddy crops were analyzed. The application of nano-formulations has shown a significant increase in plant growth promotion in rice plants under hydroponics conditions. There is no such type of comparative investigation reported earlier, and NPs of micronutrients can be utilized as a new economic nanofertilizer and can be applied to plants for their growth promotion.

Effect of Microclimate Modification on Growth and Yield of Basmati Rice under Punjab Conditions

The field experiments were conducted at the Research Farm, Department of Climate Change and Agricultural Meteorology, Punjab Agricultural University, Ludhiana during kharif 2018. Pusa Basmati variety was transplanted on 5th July (D1) and 15th July (D2) under three spacing (25 cm x12 cm, 20 cm x 15 cm and 30 cm x 10 cm). The micrometeorological data on photosynthetically active radiation (PAR) was recorded at different phenological stages. The periodic biometric observations on leaf area index were recorded. Growing degree days (GDD) were calculated at different phenological stages. The results indicate that PAR interception and leaf area index was higher under wider spacing (30 cm x 10 cm) followed by closer spacing (20 cm x 15 cm and 25 cm x 12 cm). The leaf area index was higher under wider spacing (30 cm x 10 cm) followed by closer spacing (20 cm x 15 cm and 25 cm x 12 cm). Correlation coefficients were worked out between periodic number of tillers of rice and temperature (maximum and minimum) and sunshine hours/day. In both dates of transplanting, maximum temperature showed a significant negative correlation with tiller number in most of the cases. The sunshine hours in both dates of transplanting showed a positive and significant correlation under different treatments. The first date of transplanting reported higher grain yield (30.61 q/ha) as compared to second date of transplanting (27.20 q/ha). The higher grain yield (30.57 q/ha) was recorded in basmati rice transplanted under wider spacing (30 cm x 10 cm) in comparison to closer spacing of 20 cm x 15 cm (29.25 q/ha) and 25 cm x 12 cm (26.89 q/ ha). Hence, microclimate modification through dates of transplanting and spacing is cost effective measure for increasing basmati rice yield.

Melatonin induces acclimation to heat stress and pollen viability by enhancing antioxidative defense in rice (Oryza sativa L.)

Melatonin is a signalling molecule in plants which act as a growth regulator and stress buffering agent but little is known about its defensive role in heat stress tolerance in rice. In this study we analysed the acclimation response of two contrasting heat responsive rice genotypes NERICA-L-44 (NL-44, heat stress tolerant) and Pusa Basmati 1121 (PB-1121, heat stress susceptible) to exogenous melatonin treatment under heat stress. Heat stress induces melatonin biosynthesis in both the genotypes and maximum increase was observed in NL-44. Application of exogenous melatonin further increases melatonin biosynthesis and endogenous content significantly in PB-1121. To understand melatonin’s role in alleviating effects of heat stress, some of the heat stress associated traits such as membrane stability index, hydrogen peroxide content, malondialdehyde content, total antioxidant capacity and enzymatic antioxidants like superoxide dismutase, catalase, ascorbate peroxidase and peroxidase were analysed. We observed that melatonin significantly enhanced membrane stability by reducing hydrogen peroxide mediated membrane damage. Higher activity of antioxidative enzymes and increased total antioxidant capacity helped to maintain reactive oxygen species homeostasis by scavenging mechanism. Exogenous melatonin increased pollen viability, spikelet fertility and grain yield under heat stress treatment. The findings of this study indicates that heat stress induced increase in melatonin biosynthesis may be involved in heat stress tolerance in rice. Exogenous melatonin treatment can further improve heat stress tolerance in susceptible rice genotype (PB-1121) by activating antioxidative mechanism.

Incidence and epidemiology of rice (<i>Oryza sativa</i>) false smut caused by <i>Ustilaginoidea virens</i> in northern India

False smut of rice (Oryza sativa L.) caused by Ustilaginoidea virens (Cooke) Takah., 1896 is an important emerging disease of rice. An experiment was conducted during 2018–19 and 2019–20 at Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh to study the U. virens prevalence and morphological variability in northern India with the effect of weather variables on the percentage disease incidence (PDI) of false smut of rice. The study revealed that the false smut incidence was higher in Varanasi district of Uttar Pradesh (53.64%). The lowest percentage (20.68–27.55%) of infected tillers was found in Kangra district of Himachal Pradesh, and Tehri Garhwal district of Uttarakhand. The grain replacement percentage was highest in the Moti cultivar (51.17%), while the highest yield loss percentage was in the Pusa Basmati (57.11 %) variety. The majority of the isolates in our investigation had fluffy, raised, and irregular colony morphology. The correlation between the false smut disease incidence and weather has been evaluated in the Varanasi district, and found that the temperature of 20.36°C with an RH of 85.13% and low rainfall of 8.92 mm was conducive to disease initiation and positively correlated with the PDI. Other epiphytotic factors like sunshine hours, and wind speed were all found to be negatively linked with PDI. In this investigation, for the first time, the viability of spores was also checked. It was found that 2-year-old spores were not viable because they did not retain any Brilliant Cresyl blue colour dye, which stains the stored food material in spores, while 1-month-old spores were found to be 100% viable. All the isolates were further confirmed with the specific ITS marker.

Fine mapping of qBK1.2, a major QTL governing resistance to bakanae disease in rice.

Bakanae disease caused by Fusarium fujikuroi is an emerging disease of rice causing losses in all rice-growing regions around the world. A BC2F2 population was developed by backcrossing the recurrent parent Pusa Basmati 1121 (PB1121) with the recombinant inbred line RIL28, which harbors a major quantitative trait locus (QTL) governing resistance to bakanae, qBK1.2. MassARRAY-based single-nucleotide polymorphism (SNP) assays targeting the genomic region of qBK1.2 helped in fine mapping the QTL to a region of 130 kb between the SNP markers rs3164311 and rs3295562 using 24 recombinants. In-silico mining of the fine-mapped region identified 11 putative candidate genes with functions related to defense. The expression analysis identified two significantly differentially expressed genes, that is, LOC_Os01g06750 and LOC_Os01g06870, between the susceptible genotype PB1121 and the resistant genotypes Pusa1342 and R-NIL4. Furthermore, the SNPs identified in LOC_Os01g06750 produced minor substitutions of amino acids with no major effect on the resistance-related functional motifs. However, LOC_Os01g06870 had 21 amino acid substitutions, which led to the creation of the leucine-rich repeat (LRR) domain in the resistant genotype Pusa1342, thereby making it a potential candidate underlying the major bakanae-resistant QTL qBK1.2. The markers used in the fine mapping program are of immense utility in marker-assisted breeding for bakanae resistance in rice.

Genetic Enhancement for Biotic Stress Resistance in Basmati Rice through Marker-Assisted Backcross Breeding.

Pusa Basmati 1509 (PB1509) is one of the major foreign-exchange-earning varieties of Basmati rice; it is semi-dwarf and early maturing with exceptional cooking quality and strong aroma. However, it is highly susceptible to various biotic stresses including bacterial blight and blast. Therefore, bacterial blight resistance genes, namely, xa13 + Xa21 and Xa38, and fungal blast resistance genes Pi9 + Pib and Pita were incorporated into the genetic background of recurrent parent (RP) PB1509 using donor parents, namely, Pusa Basmati 1718 (PB1718), Pusa 1927 (P1927), Pusa 1929 (P1929) and Tetep, respectively. Foreground selection was carried out with respective gene-linked markers, stringent phenotypic selection for recurrent parent phenotype, early generation background selection with Simple sequence repeat (SSR) markers, and background analysis at advanced generations with Rice Pan Genome Array comprising 80K SNPs. This has led to the development of Near isogenic lines (NILs), namely, Pusa 3037, Pusa 3054, Pusa 3060 and Pusa 3066 carrying genes xa13 + Xa21, Xa38, Pi9 + Pib and Pita with genomic similarity of 98.25%, 98.92%, 97.38% and 97.69%, respectively, as compared to the RP. Based on GGE-biplot analysis, Pusa 3037-1-44-3-164-20-249-2 carrying xa13 + Xa21, Pusa 3054-2-47-7-166-24-261-3 carrying Xa38, Pusa 3060-3-55-17-157-4-124-1 carrying Pi9 + Pib, and Pusa 3066-4-56-20-159-8-174-1 carrying Pita were identified to be relatively stable and better-performing individuals in the tested environments. Intercrossing between the best BC3F1s has led to the generation of Pusa 3122 (xa13 + Xa21 + Xa38), Pusa 3124 (Xa38 + Pi9 + Pib) and Pusa 3123 (Pi9 + Pib + Pita) with agronomy, grain and cooking quality parameters at par with PB1509. Cultivation of such improved varieties will help farmers reduce the cost of cultivation with decreased pesticide use and improve productivity with ensured safety to consumers.

Integrated management practices against an emerging Bakanae disease of rice under the hot-humid climate of Indo-Gangetic plains of India

Bakanae disease caused by Fusarium fujikuroi is emerging in India. In this work, fungicides and biocontrol agents were evaluated as seed, seedling treatment, and foliar spray(s) against bakanae disease in rice under field conditions. Carbendazim (50% WP) was found to be the most effective fungicide for seed and seedling root dip treatments. Soil drenching with 0.25% carbendazim (50% WP) 5 days before transplanting of seedlings was effective for large scale treatments. Foliar spray of 0.1% tebuconazole 50%+ trifloxystrobin 25% w/w (75 WG) significantly reduced the percentage of infected seeds (7.17%) compared with the control (32.50%). The minimum disease incidence (31%) was observed when seeds were treated with Talaromyces flavus. Individual treatments were integrated in the form of six management modules and evaluated under the field conditions of New Delhi (India) and Pusa Bihar (India) with the susceptible cultivars ‘Pusa Basmati 1121’ and ‘Pusa 1176’. Bakanae disease incidence was lower in the modules tested compared with the inoculated control or the individual treatment. The most favorable results at two locations achieved the lowest disease incidence of 7% and 2.41%.

Susceptibility of different Basmati rice varieties to bakanae disease and it’s integrated management in rice cultivar Pusa Basmati 1121

Susceptibility of different Basmati rice varieties to bakanae disease and it’s integrated management in rice cultivar Pusa Basmati 1121

Evaluation of variable doses of tachnid fly, <i>Sturmiopsis inferens</i> for the management of <i>Sesamia inferens</i> under field conditions in rice and wheat

Evaluation of variable doses of tachnid fly, Sturmiopsis inferens for the management of pink stem borer, Sesamia inferens under field conditions in basmati rice (var. Pusa Basmati 1121) and wheat (var. HD 2967) was carried out at a farmer’s field in Ludhiana. Two intervals, i.e. one at 10 days and the other at 15 days were followed for releasing different doses (75, 100, 125 and 150 gravid females/ha) of S. inferens during August-October in rice and November-December in wheat. In case of Basmati rice, the minimum incidence of Sesamia inferens was recorded in treatment where a higher dose of 150 gravid females per ha was released (1.05 % DH at 75 DAT, 1.09 % WE), which was significantly at par with the dose of 125 gravid females per ha. The untreated control plot observed the highest incidence of Sesamia inferens (1.81% DH, 2.11% WE). The observations on grain yield revealed that higher doses of 125 and 150 per ha were significantly superior (37.90-38.41 q/ha) while doses of 100 and 75 per ha were at par with each other (36.35 and 36.91 q/ha, respectively) and minimum grain yield was recorded in untreated plots (34.73 q/ha). In the case of wheat, the minimum incidence was recorded in a treatment where a higher dose of 150 gravid females per ha was released (1.49% DH at 45 DAS, 1.28% WE), which was significantly at par with the dose of 125 gravid females per ha (1.66 % DH at 45 DAS, 1.50% WE). The untreated control plot observed the highest incidence (2.48 % DH at 45 DAS, 2.65% WE). The higher doses of 125 and 150 per ha were significantly superior in terms of grain yield (46.68-47.17 q/ha), while doses of 100 and 75 per ha gave a yield of 45.41 and 44.13 q/ha, respectively.