Search

Salt stress is one of the most divesting abiotic stresses for pulse crops. Identification of salt tolerant indigenous microorganisms from pulses rhizosphere is an effective and important approach to mitigate the soil salinity. In the present investigation, effect of IIPRTh-3 (Trichoderma harzianum) on reduction of wilt disease under salinity stress and defense enzyme induction on pigeonpea plants. Out of 56 studied Trichoderma isolates, only nine isolates viz. IIPRTh-3, IIPRTlg-2, IIPRTh-10, IIPRTh-22, IIPRTh-15, IIPRTas-12, IIPRTh-39, IIPRTas-15, and IIPRTh-38 were able to grow and sporulate in a growth medium containing up to 10% NaCl. IIPRTh-3 was able to grow at 11% of salt concentration and showed maximum inhibition of Fusarium udum mycelium. This isolate also reduces the incidence of wilt in treated plants. Our ongoing research is directed towards developing fungal bioformulation to assay multiple stress tolerances in agriculture for agro-economically important pulses such as pigeonpea. [ABSTRACT FROM AUTHOR]

Twenty-nine exotic common bean germplasms and three elite cultivars were examined for phenotypic diversity in two bean-producing environments (Kanpur and Shimla) across three winter seasons and one rainy season. The estimate of genetic variability parameters revealed that the exotic bean germplasm has enough diversity for all the evaluated features. The highest genotypic and phenotypic coefficients of variation were found in seed yield, followed by 100-seed weight, pods per plant and pod length. Furthermore, seed yield was the most heritable and genetically advanced quantitative feature, followed by 100-seed weight, pod length and pods per plant. According to a trait association study, the days to maturity of phenological traits have a strong positive correlation with the days to initial flowering and the days to 50% flowering. Pods per plant and seeds per pod most strongly influence increased grain yield. The first two principal components accounted for 63.3% of the variation and demonstrated significant diversity among exotic bean lines for the traits studied, according to the principal component analysis. According to the hierarchical clustering analysis, 29 accessions and three cultivars were divided into three groups. Cluster I contains early flowering and maturing accessions, while cluster III contains high pods per plant and an increased grain yield of germplasms. The fundamental source of phenological fluctuations in both environmental circumstances is temperature. This study found four genetically divergent and stable performance accessions, including EC932021, EC932189 (earliness), and EC931452, EC931971 (high grain yield), which may aid in the establishment of a bean breeding programme. [ABSTRACT FROM AUTHOR]

Stored legumes suffer both quality and quantity deterioration due to infestation by bruchids. Recently, plant essential oils (EOs) are recognized as safer substitutes to manage these pests by alleviating the concerns of residue and resistance problem of synthetic grain protectants. Insecticidal, sub-lethal and residual effects of Pogostemon cablin Benth, Mentha arvensis L., Cymbopogon martinii (Roxb.) Wats., Pelargonium graveolens L. and Acorus calamus L. EOs were investigated against Callosobruchus analis (F.) (Coleoptera: Chrysomelidae). In contact toxicity, LC50 values ranged from 0.040 to 0.362 µl/cm2, being lowest for P. cablin. Cymbopogon martinii, P. graveolens and A. calamus EOs had strong repellent property (> 83%), while M. arvensis and P. cablin demonstrated moderate repellency (41–67%) at sub-lethal concentrations. Sub-lethal exposure reduced the oviposition (5.96–100%) and inhibited progeny emergence (21.22–100%) in dose-dependent manner. Acorus calamus EO showed potent oviposition deterrency and progeny emergence was totally abolished. EOs exhibited moderate to high residual activity, where M. arvensis and A. calamus treated seeds were completely protected (0% damage) for 70- and 84-days post-treatment. Results indicated the promising potential of five EOs to be used as bioactive ingredients for developing grain protectants to prevent post-harvest deterioration of legumes. [ABSTRACT FROM AUTHOR]

Gram pod borer (H. armigera) and tobacco caterpillar (S. litura) causes huge economical losses in different crops, identifying a novel and safe biological origin insecticides for their management is always being an important approach. Actinobacteria has significance for their bioactive compounds production and diverse ecological functions. However, little was known for antilarval traits of actinobacteria inhabiting upper gangetic agro-climatic zone of India, so, a study was conducted to explore, isolate and characterize the antilarval actinobacteria. Morphological characters and 16S rRNA gene sequence revealed that isolated actinobacteria strains were belonged to Streptomyces spp., Amycolatopsis spp., Nocardiopsis spp., Saccharopolyspora spp. genera, of which Streptomyces spp. was dominant genera. Streptomyces puniceus IIPR:TB01:01 and Streptomyces badius IIPR:KR04:01 strains (EtoAc extracts) exhibited 78% and 81% larval mortality against H. armigera and S. litura, respectively, were at par with insecticides (Emamectin benzoate 5G and Spinosad 45SC) treatments, indicating those are potential insecticidal strains. Juvenometric activity (extended larval duration and larval-pupal intermediates) of actinobacteria extract was noticed in H. armigera (up to 25 days) and S. litura (up to 28 days) compared to control (15–16 days). Potential actinobacteria strains also witnessed neurotoxic effect (blackening of larva) and lower survival probabilities in H. armigera and S. litura larvae. This study identified phenomena like neurotoxicity and juvenile hormone activity of actinobacterial extract against H. armigera and S. litura. The actinobacteria strains isolated in this study were new and their antilatval potential was not studied earlier, thus current findings advance the isolation and purification of antilarval compounds from aforesaid potential strains. [ABSTRACT FROM AUTHOR]

A pest scout data in pigeonpea (leaf webber, plume moth, pod borer) and chickpea (pod borer) crops including daily insect pest counts for three successive seasons (2015/16—2017/18) at western and eastern plateau hills (agro-climatic zones) of India was analysed for spatio-temporal dynamics. Longer infestation (different crop phenological growth stages) behaviour of leaf webber and pod borer in pigeonpea and chickpea, respectively influenced their increased mean counts (incidence). Weekly mean counts of leaf webber, plume moth and pod borer in both the crops varied significantly between the seasons. Linear incremental change in mean counts of leaf webber and pod borer on pigeonpea and chickpea, respectively was observed across the seasons (inter-seasonal). Intra-seasonal built-up of plume moth (pigeonpea) and pod borer (pigeonpea and chickpea) mean counts was also noticed. On pigeonpea, leaf webber and plume moth mean counts never reached an economic threshold level (3 larvae/plant), but crossed the advisory level (1.5 larvae/plant). It was observed that there was incremental rise in pod borer mean counts and crossing economic threshold level over seasons in chickpea (1 larvae/m row length), while it was not the case in pigeonpea (1 larvae/ plant). Furthermore, survival and management strategies of leaf webber, plume moth and pod borer in pigeonpea and pod borer in chickpea were discussed. [ABSTRACT FROM AUTHOR]

Root lesion nematode (RLN; Pratylenchus thornei) causes extensive yield losses in wheat worldwide and thus pose serious threat to global food security. Reliance on fumigants (such as methyl bromide) and nematicides for crop protection has been discouraged due to environmental concerns. Hence, alternative environment friendly control measures like finding and deployment of resistance genes against Pratylenchus thornei are of significant importance. In the present study, genome-wide association study (GWAS) was performed using single-locus and multi-locus methods. In total, 143 wheat genotypes collected from pan-Indian wheat cultivation states were used for nematode screening. Genotypic data consisted of > 7K SNPs with known genetic positions on the high-density consensus map was used for association analysis. Principal component analysis indicated the existence of sub-populations with no major structuring of populations due to the origin. Altogether, 25 significant marker trait associations were detected with − log10 (p value) > 4.0. Three large linkage disequilibrium blocks and the corresponding haplotypes were found to be associated with significant SNPs. In total, 37 candidate genes with nine genes having a putative role in disease resistance (F-box-like domain superfamily, Leucine-rich repeat, cysteine-containing subtype, Cytochrome P450 superfamily, Zinc finger C2H2-type, RING/FYVE/PHD-type, etc.) were identified. Genomic selection was conducted to investigate how well one could predict the phenotype of the nematode count without performing the screening experiments. Prediction value of r = 0.40 to 0.44 was observed when 56 to 70% of the population was used as a training set. This is the first report where GWAS has been conducted to find resistance against root lesion nematode (P. thornei) in Indian wheat germplasm. [ABSTRACT FROM AUTHOR]

Susceptibility to root-knot nematodes (Meloidogyne spp.) is one of the major factors limiting mungbean production in South and South-East Asia. Host-pest-environment interaction in mungbean and root-knot nematode (M. incognita) was investigated in multi-location field evaluation using 38 promising mungbean genotypes extracted from initial evaluation of 250 genotypes under sick plots considering second stage freshly hatched juvenile as inoculants. The extent of environmental and genotype-by-environment interactions (GGE) was assessed to comprehend the dynamism of resistance and identification of durable resistant mungbean genotypes. Among environmental factors, nematode activity was highly influenced by rainfall and minimum temperature. The GGE biplot and multiple comparison tests detected a higher proportion of genotype × environment (GE) interaction followed by genotype and environment on number of nematode galls, gall index and reproduction factor. The first two principal components (PCs) explained 64.33% and 66.99% of the total variation of the environment-centered gall scoring and reproduction factor data, respectively. The high GE variation indicated the presence of non-cross over interactions which justify the necessities of multi-location testing. Detection of non-redundant testing locations would expedite optimum resource utilization in future. The GGE biplot analysis identified genotypes such as PM-10-12, IPM-410-3 and NVL-641 as the outperforming and desirable genotypes with durable resistance against M. incognita which can be exploited in mungbean breeding programmes globally. On the contrary, the highest gall scoring and reproduction factor were recorded in genotype IPM-9901-8. Computation of confidence interval (CI) at 95% level through bootstrapping increased precision of GGE biplot towards genotype recommendation. Furthermore, total phenol content, ascorbic acid, phenlylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities were also higher in identified resistant genotypes and this information would be useful for devising mungbean breeding strategies in future for resistance against root-knot nematodes. [ABSTRACT FROM AUTHOR]

Root exudates of sorghum plants collected via root exudates trapping system after proper fractionation, give rise a total of five allelofractions of different polarity range i.e. polar to non-polar. The fractions were found to enrich about one major compound in each which was extracted out in purity of 95% by repeatedly following the fractional crystallization and column chromatographic techniques. All these five compounds viz. C, B, A, E and D were converted to three Emulsifiable Concentrate (EC) and two Emulsive Water (EW) formulations. Laboratory bioassay experiments conducted during 2009 and 2010 at IIPR, Kanpur revealed that the Polarity of the compounds used in formulations play key role in imparting toxicity against second stage juveniles (J2) of Meloidogyne javanica. EC formulation of fractions C and B (non-polar) was found 100% toxic to the juveniles at 300 and 700 μg ml-1 concentrations, respectively at the 24 and 48 hours of incubation. EC and EW formulations of the fractions A and E (medium polarity) showed 100% toxicity at 1100 and 1500 μg ml-1 concentrations respectively, at an incubation period of 72 h, while EW formulation of fraction D (completely polar) found almost ineffective in all its test concentrations ranging from 1000-2000 μg ml-1. EC of C (highly non-polar) at 250 μg ml-1 also retarded in egg hatching of test nematode up to the extent of 98%. IR, 1HNMR, 13CNMR of C and B showed flavanol skeleton as a basic chemical moiety in their chemical structures, however, both differ structurally in respect of their functional substituents and the position of attachment at flavanol skeleton. [ABSTRACT FROM AUTHOR]

Inheritance of protruded stigma in black gram [Vigna mungo (L.) Hepper] was investigated in the F1, F2, and F3 generations of four crosses and their reciprocals involving a natural flower mutant with its parent genotype (IPU 99-167) and three other genotypes (PLU 710, Type 9, and Barabanki local). The outcrossing in the mutant was due to a flower mutant with protruded stigma and crumpled petals, thus presenting a physical condition for functional male sterility. The mutant plants appeared in the parent population at an average frequency of 3.05%. The F1 plants showed normal flowers with normal pod and seed set. The segregation analysis of F2 and F3 populations indicated a single recessive gene conditioning protruded stigma and crumpled petals with pleiotropic effect. The gene symbol stg1stg1 is proposed for this mutation. Under natural conditions in the crossing block, 100% of the seeds obtained from the mutant plants were the result of cross pollination despite 93.6% pollen viability. However, the number of seeds produced by the mutant was 92% less than normal plants. Although the mutant genotype provides a mechanism for outcrossing, unless the poor seed set can be improved (e.g., by delayed planting), its use in exploiting heterosis and population improvement will be limited. [ABSTRACT FROM AUTHOR]