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Deviations in the biochemical composition and the formation of secondary metabolites have all been linked to the metabolic fluxes that underlie plant resistance. The current investigation was undertaken to know the induced defence against Lipaphis erysimi (Kalt.) via altered metabolic flux in Brassica juncea (L.) Czern. Pusa Mustard 30, RH 749, NRCHB 101, DRMR 150-35, RH 0406, Pusa Mustard 27 and Pusa Vijay had higher levels constitutive photosynthetic pigments, activity of constitutive enzymes and total glucosinolates, except in a few cases. However, due to infestation by the L. erysimi, the levels of photosynthetic pigments and total glucosinolates significantly decreased, while the activity of antioxidative enzymes and myrosinase increased. However, decrease in the photosynthetic pigments was significantly higher in NRCHB 101, RLC 3, DRMR 150-35, Chattisgarh Sarson and Pusa Double Zero Mustard 31, except in a few cases. Further, RH 725, Pusa Mustard 26, DRMR 150-35, NRCHB 101 and RH 0406 displayed significant enhancement in the antioxidative enzymes, except in a few cases. Total glucosinolate content reduced significantly in Pusa Mustard 26, DRMRIJ 16-38, NRCHB 101, DRMR 150-35 and RH 749, while the activity of myrosinase enhance notably in Pusa Vijay, Pusa Double Zero Mustard 31, Pusa Mustard 25 and NRCHB 101. Present study displayed phytochemicals defence against L. erysimi through shift in the levels of various pigments, enzymes and glucosinolate content. Cultivars RH 725, Pusa Mustard 26, DRMR 150-35, NRCHB 101 and RH 0406 showed significant variation the induced levels of various phytochemicals and enzymes, thus cane be used in Brassica breeding programme. [ABSTRACT FROM AUTHOR]

Bionomics of an insect and metabolic flux of the host plant are important tools to decipher the status of plant resistance against insect species. This study illuminates vital information on aphid‐induced levels of phytochemicals in the siliquae of Brassica juncea cultivars and their effect on host selection and population growth parameters of Lipaphis erysimi. The current study unveiled that the siliquae preference, intrinsic rate of increase (r), finite rate of increase (λ), gross reproductive rate (GRR) and net reproductive rate (R0) were significantly lower on Pusa Mustard 27, DRMR 150‐35, RLC 3, NRCHB 101, Pusa Mustard 26 and Pusa Mustard 25. However, the mean generation time (T) and doubling time (DT) of L. erysimi were significantly longer (p < 0.001) in these genotypes. These cultivars were also found with elevated levels of aphid‐induced phytochemicals and their associated enzymes, except in a few cases. Total antioxidants, ferric ion reducing antioxidant power, chlorophyll A, total chlorophyll, ascorbate oxidase (AO), catalase, phenylalanine ammonia lyase (PAL) and myrosinase were found to contribute 49.18–85.30% variation for siliquae preference and bionomics of L. erysimi on the test B. juncea cultivars. The study revealed that phenols, antioxidants, chlorophyll A, chlorophyll B, total carotenoids, AO, ascorbate peroxidase, PAL, tyrosine ammonia lyase and myrosinase had significant and negative direct consequences on the siliquae preference and bionomics, thus can be exploited as biochemical markers to identify sources of resistance against L. erysimi. Furthermore, DRMR 150‐35, NRCHB 101, RLC 3, Pusa mustard 26, RH 749 and Pusa Mustard 27 were found with greater aphid‐induced defence phytochemicals and detrimental effects on the host selection and bionomics of L. erysimi, thus can be deployed in Brassica improvement program. [ABSTRACT FROM AUTHOR]

Background: Lectins are carbohydrate binding proteins which perform diverse roles in plants. One important role is in plant defense. These proteins hold great potential as entomotoxic proteins as a part of integrated pest management. Methods: Lectins were purified and characterized from seeds of two legumes, Glycine max-Soybean and Lens culinaris-Lentil, employing ammonium sulfate fractionation and ion exchange chromatography. Bioefficacy of the purified lectins was evaluated against mustard aphid. Result: Lectins isolated from seeds of soybean (Glycine max agglutinin GMA-I, II) and lentil (Lens culinaris agglutinin LCA-I) were purified upto 9.30 (GMA-I), 4.60 (GMA-II) and 8.70 (LCA-I) fold, respectively. Lectin characterization revealed that soybean agglutinin and lentil agglutinin were specific towards D-Galactose and D-mannose, respectively. Insect bioassay was carried out with five different concentrations (10, 20, 30, 40, 50 µg/ml) of purified lectins of soybean and lentil against mustard aphid. The lethal concentration LC50 value for GMA-I was obtained as 32.1 µg/ml with a 95% confidential interval of 18.2 to 40.5 µg/ml and that of LCA-I was 19.1 µg/ml with a 95% confidential interval of 9.3 to 26.8 µg/ml. Lentil lectin (LCA-I) with lower LC50 value, was found to be the potential candidate for integrated pest management. [ABSTRACT FROM AUTHOR]

Rapeseed-mustard, the oleiferous Brassica species are important oilseed crops cultivated all over the globe. Mustard aphid Lipaphis erysimi (L.) Kaltenbach is a major threat to the cultivation of rapeseed-mustard. Wild mustard Rorippa indica (L.) Hiern shows tolerance to mustard aphids as a nonhost and hence is an important source for the bioprospecting of potential resistance genes and defense measures to manage mustard aphids sustainably. We performed mRNA sequencing of the R. indica plant uninfested and infested by the mustard aphids, harvested at 24 hours post-infestation. Following quality control, the high-quality reads were subjected to de novo assembly of the transcriptome. As there is no genomic information available for this potential wild plant, the raw reads will be useful for further bioinformatics analysis and the sequence information of the assembled transcripts will be helpful to design primers for the characterization of specific gene sequences. In this study, we also used the generated resource to comprehensively analyse the global profile of differential gene expression in R. indica in response to infestation by mustard aphids. The functional enrichment analysis of the differentially expressed genes reveals a significant immune response and suggests the possibility of chitin-induced defense signaling. [ABSTRACT FROM AUTHOR]

The study aimed to decipher the variation in constitutive plant biochemicals, and their influence on development, reproduction and survival of Lipaphis erysimi (Kaltenbach) (Aphididae: Hemiptera) on diverse Brassica juncea (L.) Czern & Coss. (Brassicales) cultivars. These studies revealed significant differences in total nymphal, reproductive and developmental periods, fecundity and offspring survival of L. erysimi on the test B. juncea cultivars. Toal developmental period was significantly longer, while fecundity and survival were lower on Pusa Mustard 27, NRCHB 101, RLC 3, RH 749, RH 725, DRMR 150-35, Pusa Mustard 26 and Pusa Mustard 25, except in a few cases. Further, total protein, antioxidants, tannins, phenols, FRAP, glucosinolates, photosynthetic pigments and different enzymes tested were significantly higher, and total sugars lower in Pusa Mustard 32, Pusa Mustard 30, NRCHB 101, RLC 3, DRMR 150-35, Pusa Mustard 26 and Pusa Mustard 27 as compared to other B. juncea cultivars, except in a few cases. Total sugars exhibited significant and positive association with survival of L. erysimi, while total protein, ferric ion reducing power, chlorophyll A, carotenoids, catalase, phenyl ammonia lyase and tyrosine ammonia lyase showed significant and negative correlation with survival of L. erysimi. Further, the biochemical constituents suggested 94.99, 95.88, 95.30, 97.06 and 84.75% variation in total nymphal, reproductive and total developmental periods, fecundity and survival of the L. erysimi on the test B. juncea cultivars, respectively. Overall, DRMR 150-35, RLC 3, NRCHB 101 and Pusa Mustard 26 have higher amounts of anti-nutritional defence compounds and antioxidative enzymes, distress the growth and survival of L. erysimi, and thus could be deployed in Brassica improvement programme. [ABSTRACT FROM AUTHOR]

Indian mustard, Brassica juncea holds distinction of being second most significant contributor to the production of edible oilseeds in India. This crop encounters nearly 50 distinct kinds of insect pests. Among the several pest species, Lipaphis erysimi (Kaltenbach), commonly known as the mustard aphid, is responsible for causing substantial yield losses. The behaviour, development, and reproduction of aphids can be impacted by the nutritional composition of different plant components. Genotypes, within and between different species of Brassica(s), encompass a range of diversity and, thus, exhibiting varying levels of resistance to mustard aphids. The biochemical composition of different plant parts in mustard, such as leaves, buds, and siliqua, can exert a range of effects on infestation by L. erysimi. Specific dietary components have the capacity to allure aphids and promote their population growth. On the other hand, additional elements such as glucosinolates or other defense compounds exhibit the capacity to deter aphids. Therefore, the study was planned to elucidate the intrinsic constitutive and aphid-induced biochemical defense mechanisms in B. juncea and examine the impact on L. erysimi. Among 30 genotypes, it was observed that TN 3, EC 61–9-2–2-2, NPJ 50, Rohini, IC 355399, RLC 3, and Kranti exhibited elevated levels of biochemical components, reduced preference by aphids, and a significant increase in aphid induced biochemical contents. The impact of these modifications on the behaviour and establishment of L. erysimi was also examined. Overall, the biochemical constituents identified in B. juncea and elaborated their effect on growth and development of L. erysimi are suggested to be effectively employed for breeding Indian mustard genotypes with in-built resistance to L. erysimi. [ABSTRACT FROM AUTHOR]

The field experiments on "Screening of Brassica germplasm against mustard aphid, Lipaphis erysimi Kalt." were conducted at Students' Instructional Farm of C. S. Azad University of Agriculture & Technology, Kanpur, India during Rabi 2021-22 and 2022-23. Fifty Brassica germplasm were evaluated on the basis of the Aphid Infestation Index (A.I.I.) (0-5 scale) twice, first at 50% flowering stage and second at the pod setting stage. The population of mustard aphids was observed in 50 germplasm taken under screening to see the performance of germplasm based on the level of infestation of mustard aphids. Based on A.I.I. the germplasm viz., RC-2, RC-4, RC-6, RC-14, RC-19, RC-20, RC-22, RC-24, RC-25, RC-37, RC-39, RC-46 and RC-49 were found to be resistant; while the germplasm viz., RC-8, RC10, RC-12, RC-15, RC-16, RC-18, RC-21, RC-35, RC-38, RC-41, RC-42, RC-44, and RC-48 were found to be moderately resistant. Based on the aphid population, the germplasm viz., RC-5, RC-20, RC-23 and RC-37 were categorized as resistant; the germplasm viz., RC-2, RC-9, RC-13, RC-14, RC-22, RC-25, RC-29, RC-35, RC-40, RC-42, RC-44, RC-45, RC-46, RC-47, RC-49 and RC-50 were found to be moderately resistant, while RC-24 was found to be susceptible. [ABSTRACT FROM AUTHOR]

In this study, the resistance of selected canola genotypes to the mustard aphid Lipaphis erysimi (Kaltenbach) was investigated. Molecular characterization of plant resistance was conducted, and genetic variability was observed between the resistant (KS-75) and susceptible (Abaseen) genotypes of brassica. Three RAPD markers were identified that were associated with the resistance. This study was conducted to compare the genetic data between two genotypes (KS-75 resistant and Abaseen susceptible), with an average of 4.3 bands per primer. The amplification bands per primer ranged from 9 to polymorphic fragments of 8, with fragment sizes ranging from 450 to 1700 base pairs to 9 kilo base pairs (kbps). Amplification of the largest fragment in 9 kbps using four primers (A 1–12, B 1–12, K 1–12 and L 1–12) resulted in a mean 92 percent identity index between the first two resistant and susceptible genotypes. KS-75 resistant had the highest mean genetic diversity of 92 percent, while Abaseen susceptible had the lowest mean genetic diversity of 8 percent. Out of the three markers tested, two were found to be positively associated with aphid resistance, while one was negatively correlated. These markers can be used to help develop a pre-emptive strategy for aphid resistance in brassica species, without having to simultaneously select for yield and quality related traits.

In this study, the resistance of selected canola genotypes to the mustard aphid Lipaphis erysimi (Kaltenbach) was investigated. Molecular characterization of plant resistance was conducted, and genetic variability was observed between the resistant (KS-75) and susceptible (Abaseen) genotypes of brassica. Three RAPD markers were identified that were associated with the resistance. This study was conducted to compare the genetic data between two genotypes (KS-75 resistant and Abaseen susceptible), with an average of 4.3 bands per primer. The amplification bands per primer ranged from 9 to polymorphic fragments of 8, with fragment sizes ranging from 450 to 1700 base pairs to 9 kilo base pairs (kbps). Amplification of the largest fragment in 9 kbps using four primers (A 1–12, B 1–12, K 1–12 and L 1–12) resulted in a mean 92 percent identity index between the first two resistant and susceptible genotypes. KS-75 resistant had the highest mean genetic diversity of 92 percent, while Abaseen susceptible had the lowest mean genetic diversity of 8 percent. Out of the three markers tested, two were found to be positively associated with aphid resistance, while one was negatively correlated. These markers can be used to help develop a pre-emptive strategy for aphid resistance in brassica species, without having to simultaneously select for yield and quality related traits. [ABSTRACT FROM AUTHOR]

The field experiments on "Screening of Brassica genotypes against mustard aphid, Lipaphis erysimi Kalt." was conducted at Students' Instructional Farm of C. S. Azad University of Agriculture & Technology, Kanpur during Rabi 2018-19 and 2019-20. Sixty Brassica genotypes were evaluated on the basis of the Aphid Infestation Index (A.I.I.) ('0-5' scale) twice first at 50% flowering stage and second at the pod setting stage. The population of mustard aphids was observed in 60 genotypes taken under screening to see the performance of genotypes based on the level of infestation of mustard aphids. Based on A.I.I. the genotypes viz., Kanti, Kranti, Jagannath, Krishna, Maya, Pusa Bahar, and Pusa Agrani (Sej 2) were found to be highly resistant. Based on the aphid population the genotypes viz., Kanti, Kranti, Jagannath, Geeta, and Maya were found to be highly resistant. [ABSTRACT FROM AUTHOR]

The study on categories of resistance in selected canola genotypes against mustard aphid (Lipaphis erysimi) was conducted under glasshouse conditions, The University of Agriculture, Peshawar during growing seasons of 2018-2019. During this study, a total of two different experiments were carried out where, antixenosis experiment, comprised three levels; seedling, flowering and pod stage. In all the three stages, only genotype 'KS-75' proved as antixenosis resistant against the aphid compared to susceptible genotype Abaseen. The second experiment was performed to test antibiosis resistance against L. erysimi among the selected genotypes. During the antibiosis experiment different life table parameters of aphids; developmental period, reproductive period, longevity and fecundity were studied. Based on the calculations, only 'KS-75' proved antibiosis resistant against L. erysimi among the selected genotypes. Thus, during our current studies, genotype KS-75 proved antixenosis and antibiosis characteristics based on less number of aphids attracted/sustained and low number of progenies produced as compared to the tested genotypes Abaseen, Omega and Zahoor showed strong vigor against mustard aphid and symptoms of attack/damages were observed. [ABSTRACT FROM AUTHOR]

Brassica juncea is the most important oilseed crop in India, and Lipaphis erysimi is a major pest of this crop. The study aimed at knowing the role of photosynthetic pigments in host preference and population build‐up by L. erysimi on diverse B. juncea genotypes. We found significant differences among test genotypes for aphid preference, multiplication rate and population build‐up, and chlorophyll A, chlorophyll B, total chlorophyll, total carotenoids and Soil Plant Analysis Development (SPAD) chlorophyll and Normalised Difference Vegetation Index (NDVI) values in healthy and aphid damaged flowers, immature siliquae and grain filled siliquae. The L. erysimi damage reduced all the photosynthetic pigments across plant parts of test B. juncea genotypes. The aphid damage resulted in change in chlorophyll B in flowers and total chlorophyll in immature siliquae showed positive association with leaf preference, while total carotenoids in flowers and grain filled siliquae had negative association with leaf and bud preference by L. erysimi. Chlorophylls A and B in the siliquae showed significant and positive association with multiplication rate and population build‐up of L. erysimi on B. juncea. Change in chlorophyll A, total chlorophyll and total carotenoids because of aphid damage contributed to 38.6% variation in host preference and 21.9% variation in multiplication rate and population build‐up of L. erysimi on different B. juncea genotypes. Genotypes PM 30, RH 749, PDZ 6, Pusa 119‐1‐3, Pusa 119‐1‐1 and Kranti were found with least leaf and bud preference, lower aphid multiplication rate and population build‐up, and higher amounts of different chlorophylls and total carotenoids, suggesting their use in aphid resistance breeding programme. TheL. erysimi damage reduced all the photosynthetic pigments across plant parts of test B. juncea genotypes. Change in chlorophyll A, total chlorophyll and total carotenoids because of aphid damage contributed to 38.6% variation in host preference and 21.9% variation in multiplication rate and population build‐up of L. erysimi on different B. juncea genotypes. Genotypes PM 30, RH 749, PDZ 6, Pusa 119‐1‐3, Pusa 119‐1‐1 and Kranti were found with least leaf and bud preference, lower aphid multiplication rate and population build‐up, and higher amounts of different chlorophylls and total carotenoids, suggesting their use in aphid resistance breeding programme. [ABSTRACT FROM AUTHOR]

All the cultivated Brassica species exhibited powdery mildew severity with highest (43.2%) on Brassica juncea followed by B. rapa (28.0%) which is widely cultivated in India. Yield losses from 10-90 per cent with reduction in 6.47 per cent oil content have been estimated from different Brassica species. Hence, the present study was carried out to evaluate different oils to manage powdery mildew disease and aphids in an organically grown mustard crop. Five oils (castor, groundnut, sunflower, neem and mustard oil) and ghee were evaluated against powdery mildew (Erysiphae cruciferarum) and aphid (Lipaphis erysimi) of Indian mustard (Brassica juncea). Castor oil 50 EC, neem oil 50 EC and mustard oil 50 EC and deshi ghee 50 EC (@ 100 ml/10 litre water) were effective over untreated control in reducing powdery mildew disease severity when applied as foliar spray (@ 5 ml/ litre) in the experiment carried out in organic field (plot No. B-2 at Agronomy Instruction Farm, S. D. Agricultural University, Sardarkrushinagar). Maximum reduction in germinated conidia (66.0%) over control, disease severity (50.0%), area under disease progress curve (AUDPC) values (51.8%) and maximum increase over control in 1000 seed weight (16.7%) and seed yield (10.3%) was observed with neem oil. This was followed by the application of ghee which exhibited reduced disease severity (22.9%) and AUDPC values (30.6%) and increased seed yield (8.1%) and the application of castor oil 50 EC which exhibited an increased in seed yield (8.0%) and reduced powdery mildew severity (20.8%). Shortest log phase was observed with neem oil during 10th std. week. All the oils tested (castor, groundnut, sunflower, neem and mustard oil) and deshi ghee were effective in reducing aphid population (39.5 to 65.9%) and damage index (6.1 to 25.1%). A maximum reduction in aphid population (65.9%) over control and lowest aphid damage index (3.70) was observed with neem oil 50 EC 6 days after 2nd spray. Application of neem oil, castor oil and deshi ghee resulted in increased seed yield (8.1 to 10.4%). This information could be useful in devising strategies for powdery mildew and aphid management in organic cultivation, eco-friendly management and IPM of mustard. [ABSTRACT FROM AUTHOR]

Hybrids have been successfully used to improve crop productivity, including Brassicas. Nucleo-cytoplasmic interactions have been reported to influence the expression of resistance to insect pests in several crops. We studied the effects of Cytoplasmic Male Sterility (CMS) in Brassica juncea carrying alien cytoplasms and their respective maintainer (B) lines on the antibiosis mechanism of resistance, involving development, survival, reproduction potential and population build-up of mustard aphid, Lipaphis erysimi, and the levels of defense phyto-chemicals. Present findings revealed that the numbers of aphids/plant, aphid multiplication rate and aphid resistance index were lower on ber CMS under natural, mori CMS under artificial infestation conditions, and juncea under both the test conditions indicating nucleocytoplasmic interactions for aphid reaction. Across cytoplasms, nymphal, reproductive and total developmental periods were significantly longer on SEJ 8, NPJ 161, LES 39, and NPJ 93, while the reproductive potential and survival were lower on PM 30, Pusa Tarak and SEJ 8 as compared to other nuclear backgrounds. Across nuclear backgrounds, nymphal, reproductive and total developmental periods were significantly longer on ber CMS, while reproductive potential and survival were lower on ber and mori CMS as compared to other cytoplasms. Total glucosinolates were significantly greater and myrosinase lower in Pusa Agrani, SEJ 8, LES 39, PM 30, NPJ 112, and Pusa Tarak as compared to the other nuclear backgrounds. Furthermore, total glucosinolates were significantly greater and myrosinase lower in ber CMS and juncea as compared to other cytoplasms. The studies suggest that CMS as well as cytoplasmic and nuclear gene interactions regulate the expression of defense compounds such as glucosinolates and determine the expression of resistance/susceptibility to L. erysimi. These findings shall help in identification of suitable L. erysimi tolerant nucleo-cytoplasmic combinations for their deployment in B. juncea hybrid breeding program. [ABSTRACT FROM AUTHOR]

Canola (Brassica napus L.) is one of the economically important crops of Pakistan and mustard aphid, Lipaphis erysimi Kalt. (Hemiptera: Aphididae), is a serious threat to this crop. This experiment was conducted with an aim to screen out selected canola cultivars for their tolerance against L. erysimi infestation under glasshouse conditions. Experiment was carried out using completely randomized design with ten replications for each treatment during growing seasons of 2018 and 2019. Data were documented based on the tolerance indices (TI) and proportional plant dry weight change (DWT) to identify tolerance of canola crop. Results revealed that commercial cultivar 'Zahoor' comparatively performed well despite higher number of aphids found on itas compared its other counterparts "Abaseen, Omega and KS-75" and hence, was identified as tolerant to mustard aphid. This cultivar also exhibited strong vigor against mustard aphid and minimal symptoms of damages were observed. The yield losses based on DWT and TI in susceptible cultivar "Abaseen" was 40.79%, whereas it was 23.56% in Zahoor which confirmed the reduced percent yield losses in the later genotype. This study identified "Zahoor" as the most tolerant cultivar to mustard aphid followed by KS-75 and Omega hence, other susceptible cultivars should be replaced by Zahoor to attain higher and sustainable yield production in canola. [ABSTRACT FROM AUTHOR]

Hybrids have been successfully used to improve crop productivity, including Brassicas. Nucleo-cytoplasmic interactions have been reported to influence the expression of resistance to insect pests in several crops. We studied the effects of Cytoplasmic Male Sterility (CMS) in Brassica juncea carrying alien cytoplasms and their respective maintainer (B) lines on the antibiosis mechanism of resistance, involving development, survival, reproduction potential and population build-up of mustard aphid, Lipaphis erysimi, and the levels of defense phyto-chemicals. Present findings revealed that the numbers of aphids/plant, aphid multiplication rate and aphid resistance index were lower on ber CMS under natural, mori CMS under artificial infestation conditions, and juncea under both the test conditions indicating nucleo-cytoplasmic interactions for aphid reaction. Across cytoplasms, nymphal, reproductive and total developmental periods were significantly longer on SEJ 8, NPJ 161, LES 39, and NPJ 93, while the reproductive potential and survival were lower on PM 30, Pusa Tarak and SEJ 8 as compared to other nuclear backgrounds. Across nuclear backgrounds, nymphal, reproductive and total developmental periods were significantly longer on ber CMS, while reproductive potential and survival were lower on ber and mori CMS as compared to other cytoplasms. Total glucosinolates were significantly greater and myrosinase lower in Pusa Agrani, SEJ 8, LES 39, PM 30, NPJ 112, and Pusa Tarak as compared to the other nuclear backgrounds. Furthermore, total glucosinolates were significantly greater and myrosinase lower in ber CMS and juncea as compared to other cytoplasms. The studies suggest that CMS as well as cytoplasmic and nuclear gene interactions regulate the expression of defense compounds such as glucosinolates and determine the expression of resistance/susceptibility to L. erysimi. These findings shall help in identification of suitable L. erysimi tolerant nucleo-cytoplasmic combinations for their deployment in B. juncea hybrid breeding program.

Lipaphis erysimi is a key pest of rapeseed-mustard in Indian subcontinent. Although chemical control is the basis of its management, the unsustainability of this approach has accelerated global research efforts to find alternate solutions. Host plant resistance is one among these. A set of introgression lines were developed using Brassica fruticulosa previously found to be resistant to L. erysimi. Rigorous screening over the years led to the identification of 3 introgression lines (I8, I79, and I82) for field resistance to aphids. We evaluated these introgression lines under field and laboratory conditions along with B. fruticulosa (resistant parent), B. juncea var. PBR-210 (susceptible parent) to elucidate the mechanism of resistance. Significantly a smaller number of aphids settled on circular leaf discs of B. fruticulosa, I8 and I82 compared to that on PBR-210 after 24 and 48 h of release. A similar trend was observed in free choice field experiment with significantly less aphid colonization on B. fruticulosa, I8, I79 and I82 compared to PBR-210 indicating lower aphid preference for these genotypes. Further, no choice experiments revealed significant negative effects of these genotypes on aphid demographic parameters (nymphal survival, development period, fecundity and longevity). Tolerance may not be a mechanism of resistance as aphid population failed to develop on these genotypes. Thus, resistance in these introgression lines may be attributed to a synergistic combination of antixenosis and antibiosis mechanisms. [ABSTRACT FROM AUTHOR]

Present studies were carried out on development and survival of Lipaphis erysimi (Kaltenbach) on diverse Brassica juncea (L.) Czern. & Coss. genotypes, and decipher the role of certain biochemical compounds in plant defense against mustard aphid. There were significant differences among test B. juncea genotypes for total nymphal duration, reproductive period, total developmental period, fecundity and survival of L. erysimi. The development period was significantly longer on PDZM 31, NRCHB 101, RP 7-3-2-2-1, TS 18-5124, RP 11-2-1-3-1, YSG, RLC 3, NPJ 50, IC 355399, MSTWR 17-1, EC 61-9-2-2-2, GP 454 and Kranti, while fecundity and survival were significantly lower on RLC 3, Kranti, IC 355399, Rohini, GP 454, NPJ 50 and TS 18-5124 as compared to other B. juncea genotypes. The biochemical constituents like, total antioxidants, tannins, phenols and FRAP were also significantly higher in RLC 3, Kranti, IC 355399, Rohini, GP 454, NPJ 50 and TS 18-5124 as compared to other B. juncea genotypes, except in a few cases. The total antioxidants and total tannins had significant and negative association, and explained 78.5% and 91.3% variability for fecundity and survival of L. erysimi, indicating their detrimental effects on progeny production and survival of mustard aphid on B. juncea. Present studies suggest that the B. juncea genotypes RLC 3, IC 355399, Rohini, GP 454, NPJ 50, TS 18-5124 and Kranti have higher amounts of test defense biochemicals and impart adverse effects on the reproductive period, fecundity and survival of L. erysimi.

An experiment was carried out to investigate the effect of abiotic factors on incidence of major insect pests of mustard during rabi 2016-17 and 2017-18 at Crop Research Centre of SVPUA & T, Meerut (UP). The results showed that the incidence of mustard aphid, painted bug and cabbage butterfly started during 3rd, 6th and 4th standard week, and attained their peaks during 8th, 10th and 9th standard week, respectively during rabi 2016-17. However, in rabi 2017-18 the incidence of mustard aphid and Cabbage butterfly started during 4th while the incidence of painted bug started during 5th standard week and attained their peaks during 9th and 11th standard week respectively. Correlation studies revealed that aphid population showed a non-significant positive correlation with morning relative humidity (r = 0.29) and non-significant negative correlation with maximum temperature (r= -0.25), minimum temperature (r = -0.37), evening relative humidity (r = -0.01) and rainfall (r= -0.13), while painted bug showed significant positive correlation with morning relative humidity (r = 0.54) and rainfall (r= 0.53) and non-significant negative correlation with maximum temperature (r = -0.04) and minimum temperature (r= -0.16) however cabbage butterfly showed non-significant positive correlation with maximum temperature (r = 0.09) and morning and evening relative humidity (r = 0.12) and (r = 0.01) and a non-significant negative correlation with minimum temperature (r= -0.25) and rainfall (r= -0.13), respectively during rabi 2016-17. However, during rabi 2017-18 aphid population indicated non-significant positive correlation with rainfall (r = 0.22) and non-significant negative correlation with maximum temperature (r= -0.11), minimum temperature (r= -0.28), morning relative humidity (r= -0.46) and evening relative humidity (r= -0.26) and painted bug population indicated positive correlation with maximum temperature (r= 0.48) and minimum temperature (r= 0.27) and a significant negative correlation with morning humidity (r= -0.50) and a non-significant negative correlation with evening relative humidity (r= -0.21) and rainfall (r= -0.36), while the larval population of cabbage butterfly indicated non-significant positive correlation with maximum temperature (r= 0.25) and morning and evening relative humidity (r= 0.44) and (r= 0.39), and a non-significant negative correlation with minimum temperature (r= -0.43), and rainfall (r= -0.28). [ABSTRACT FROM AUTHOR]

We investigated the susceptibility of five cabbage varieties ('Oxylus', 'Super Cross', 'Vantar F1 Hybrid', 'Santa'F1 and 'Fortune') to aphids. Trials were set up in the Accra plains for two rainy seasons in 2017. The first trial examined aphid infestation and the second included weekly blanket spray of neem oil at 0.48 L/ha (60 ml/15 L water) during the second rainy season. Five systematically sampled cabbage leaves per plot were examined for the numbers of aphids and associated natural enemies (predators). Symptoms of aphid attack (incidence and severity of infestation) were also recorded. Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) were the two aphid species observed and their numbers differed significantly between varieties in both seasons during the first but not the second trial. Few aphids settled on 'Oxylus', while more occurred on 'Fortune'. L. e. pseudobrassicae was the most abundant aphid on all the varieties. Aphid numbers were significantly decreased by neem application. Occurrence of natural enemies did not differ significantly between varieties, except for spiders during the major rainy season. There was no significant difference in aphid infestation between varieties during the first season as all of them completely succumbed to the infestation, while in the second season aphid incidence and severity of infestation was highest on 'Fortune', with 'Oxylus' being the least attacked by aphids. The crop yield was zero during the first season without protection for all the varieties. However, in the second season, lower yields (0.19–3.66 t/ha) was obtained with cabbage without protection, and much higher yields (14.8–21.1 t/ha) were obtained on neem-treated plots. [ABSTRACT FROM AUTHOR]

One of the major oil yielding crops Indian mustard [Brassica juncea (L.) Czern. & Coss.] is highly susceptible to mustard aphid, a hemipteran sap sucking insect-pest. Leaf-transcriptome of mustard treated with different aphid species as host and non-host revealed variable expression of three sugar transporter genes. One of these transporters BjSWEET11 was constitutively expressed under a CaMV 35S promoter in B. juncea through Agrobacterium-mediated plant transformation. The transgenic plants after requisite molecular analysis for the presence and expression of the introduced gene were assayed for their deterring effects on the infestation by mustard aphid (Lipaphis erysimi). Attenuating effect of the enhanced BjSWEET11 expression on multiplication and population growth of mustard aphids demonstrated likely involvement of this transporter in endogenous plant defense mechanism.

Lipaphis erysimi Kaltenbach is one of the economically important pests of Indian mustard Brassica juncea. Plant defense against these pests include impairing digestive processes in the insect gut. Thus, for an effective pest management, it is imperative to understand the digestive enzymes present in the pest. The present study involves the characterization of mustard aphid α-amylase and the efficacy of a potent insecticidal agent, RiD (Rorippa indica defensin) against it. The total protein of L. erysimi was analysed to determine the α-amylase activity present in it. The relative α-amylase activity in the total protein was assayed by the dinitrosalicylic acid (DNS) procedure, using 1% soluble starch as substrate and was observed to be 2.32 ± 0.025 U/mL of the total protein. The optimum temperature for α-amylase activity was found to be 35 °C and optimum pH was recorded as 6.5. Presence of RiD showed a decrease in the α-amylase activity in a non-competitive way. Moreover, cryo-sections of the aphid midgut also revealed bound RiD in the confocal analysis. [ABSTRACT FROM AUTHOR]

Efficacy of insecticides and biological control agents in an Integrated Pest Management (IPM) program requires a full understanding of both these factors and their interactions. With this in mind, a study was conducted to build an IPM strategy to control Myzus persicae (Homoptera: Aphididae) in field Mustard (Brassica compestris) crops using a combination of insecticides and biological control agents. Five different insecticides (methomyl, matrine, carbosulfan, thiamethoxam, and pymetrozine) were used to test the survival of Aphidius matricariae wasps under field and laboratory conditions. Under laboratory conditions five different concentrations (1%, 0.5%, 0.25%, 0.13% 0.06%) along with the control were made of each insecticide. Parasitoids exposed to Pymetrozine showed the highest percent emergence at 82.96%, 65.18%, 64.07%, 53.70% and 46.66% of from mummified aphids followed by thiamethoxam, carbosulfan, matrine and methomyl, whereas under field conditions none of these insecticides showed negative impacts on the emergence of A. matricariae wasps. In the presence of insecticides, no significant effect on emergence of A.matricariae wasps from mummified aphids was observed with pymetrozine showing 90.91% emergence of A. matricariae wasps, carbosulfan 81.25%, matrine 80.27%, thiamethoxam 77.29% and methomyl 75.49% emergence, respectively. In addition to observing the effect of insecticides on the emergence of A. matricariae, efficacy of these insecticides against populations of M. persicae was also studied. In order of efficacy, thiamethoxam > matrine > pymetrozine > carbosulfan > methomyl showing 91.37%, 89.61%, 72.46%, 56.6% and 54.35% reductions in aphid populations, respectively. The results of this study show that a biological control agent together with these insecticides can be used simultaneously as part of an IPM program to control M. persicae in field Mustard. [ABSTRACT FROM AUTHOR]

Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae) is one of the most promising ladybird beetle against many sucking pests. Predation rates, developmental biology, life table, and field assessment of this ladybird were examined against mustard aphid, Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae), on broccoli. Data on the life history were collected at 23 ± 1°C and 70 ± 1% RH and were evaluated using the two-sex, age-stage life table. Results showed that the two-sex, age-stage life table-based net reproductive rate (R 0) was 11.264 ± 6.197 offspring. The adult females lived longer (33.8 ± 2.356 d) than the adult males (32.2 ± 0.841 d). The fourth instar consumed most of L. erysimi (113.97 ± 5.76) compared to the other larval stages of the predator. Male (1,821) and female (2,673) consumed more aphids than larvae. The net consumption rate was 741.78 ± 89.91 aphids. Other aphidophagous predators such as Coccinella septempunctata L., Micraspis discolor (F.), Coccinella transversalis (F.), and syrphid (Diptera: Syrphidae) were also noted in broccoli. Our research showed that inoculative release of 150 or 200 adults per 1,000 m2 for two times on broccoli achieved a significant decrease in aphids L. erysimi and Brevicoryne brassicae L. (Hemiptera: Aphididae) (>95%). The release rate of 150 adults per 1,000 m2 for two times may, therefore, be recommended to manage the aphid population on broccoli. [ABSTRACT FROM AUTHOR]

Fertilizers utilization does not only play an important role in increasing the crop yield, but also they may influence the plant nutritional quality, thereby it affects the ecological interactions between herbivores and their natural enemies. In a field study, the effect of nitrogen fertilization (0, 75, 150 and 225 kg N ha−1) on population of mustard aphid, Lipaphis erysimi Kalt. (Hemiptera: Aphididae) and predatory gall midge, Aphidoletes aphidimyza (Diptera: Cecidomyiidae), in canola (Brassica napus L.), as well as their interactive impact on the plant yield was investigated. The population of aphid and predator were positively affected by nitrogen fertilization; the maximum abundances of which were observed in plants with 150 and 225 kg N ha−1 applied. However, predator to prey ratio was lower in the highest N level in comparison with the moderate level. The maximum suppression of the aphid by the predator was also observed in the moderate N level. The interactive effect of nitrogen fertilizing and the predator presence positively influenced the canola grain yield. The lowest yield losses due to aphid infestation were observed in plants fertilized with 150 kg N ha−1 in the presence of the predator. In this fertilization level, the plants could compensate the aphid damage more than the other treatment levels; hence, they produced significantly more grain yield. These findings indicate that adequate plant nutrition can help plants compensate for aphid damage and also positively affect the predator efficiency, leading to an improvement in the canola yield. [ABSTRACT FROM AUTHOR]

A field experiment on mustard var. Varuna was conducted during Rabi season of year 2013-14 and 2014-15 at CSAUA&T, Kanpur. Among the various insecticides evaluated against the mustard aphid, Lipaphis erysimi Kalt, imidacloprid 17.8 SL @ 0.2 g/litre showed highest reduction Significantly lower mean aphid intensity 14 days after second spray 6.89 and 19.66 aphids/10 cm apical shoot were recorded on the crop treated with imidacloprid 17.8 SL with 94.09 and 90.34 percent reduction over control which provided significantly highest seed yield 2287 and 2235 kg/ha with 40.73 and 37.79 percent increase in yield, respectively. Application of Thiamethoxam 25% WP was found second best treatment with 8.49 and 23.46aphids/10 cm apical shoot 14 days after second spraying with 89.91 and 87.54 percent reduction over control during both year with provided 2229 and 2216 kg/ha with 37.71 and 36.62 percent increase in yield. The ranking of insecticides on the basis percent reduction over control after second spraying after 14 days for the management of aphids most effective were imidacloprid 17.8SL and thiametoxam25 WP and least effective spinosad 45 SC. Among biopesticides M. anisopoliae 1.15 WP was more effective than B. bassiana 1.15WP.Among the chemical insecticides imidacloprid 17.8 SL found safe followed by thiamethoxam 25WP with less number of percent reducing over control. [ABSTRACT FROM AUTHOR]

Aphids are the utmost common and predominant pest of oilseed brassica crops which caused 70-80% of losses in yield. So, a study was conducted to check the comparative incidence and abundance of canola aphids, Brevicoryne brassicae, Lipaphis erysimi and Myzus persicae. Results revealed that the incidence of all aphids appeared on the leaves and the inflorescences in 3rd week of January and 2nd week of February and continued till the harvesting of Faisal Canola variety. The per leaf peak population of L. erysimi, B. brassicae and M. persicae (17.66, 12.59 and 8.49, respectively) and per inflorescence (3.82, 2.93 and 2.19, respectively) was recorded. The highest mean population ranges 60.45-70.90/leaf and 8.24- 8.94/inflorescence were observed from 08-February to 01-March and 08-February to 05- March, respectively. The temperature range of 17.67-23.33°C was suitable for the development of aphids. Predator species, Chrysoperla carnea, Coccinella undecimpunctata, and Coccinella septempunctata were recorded while the population of aphids was adequately established on the canola variety. The population of all predators increased as an increase in the population and decreased as the population of aphids decline. The present study will be helpful to take precautionary measures for the management of canola aphids when reached at economic injury level (5 aphids/leaf) on canola crop. [ABSTRACT FROM AUTHOR]

Highlights • Acmella oleracea had insecticidal action against Myzus persicae and Lipaphis erysimi. • Ethanolic extract resulted in 90% mortality of aphids and reduced its fecundity. • The extract toxicity was attributed to two alkamides. • A. oleracea extract showed no toxicity to the natural enemies of aphids. Abstract This study was conducted to evaluate the toxicity of paracress (Acmella oleracea) extracts to the aphids Myzus persicae (Sulz.) and Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae), and the extracts selectivity to the aphid parasitoid Diaeretiella rapae McIntosh (Hymenoptera: Braconidae) and to the predator Orius insidiosus (Say) (Hemiptera: Anthocoridae). We evaluated water and ethanol extracts from A. oleracea. The ethanol extract caused 90% mortality of both aphid species within 70 h and reduced their fecundity, whereas the water extract was inactive. In addition, this extract caused no mortality of the natural enemies. In an attempt to identify bioactive compounds in the ethanol extract, three alkamides, spilanthol, undeca-2 E -en-8,10-diynoic acid isobutylamide (compound 2) and (2 E)- N -(2-methylbutyl)-2-undecene-8,10-diynamide (compound 3), were isolated and tested on L. erysimi. From the isolated alkamides, spilanthol and compound 2 showed high insecticidal activity against L. erysimi , indicating that they contributed to the observed extract activity. The results of this study demonstrate the potential of the ethanol extract of A. oleracea as a botanical insecticide in the management of aphids in brassicas. [ABSTRACT FROM AUTHOR]

An attempt has been made to quantify the effect of weather parameters and ladybird beetle on population fluctuation of aphid using path analysis of data collected during rabi 2012-13 and 2013-14 at Junagadh Agricultural University, Junagadh. The result revealed that the direct effect of minimum and maximum temperatures on aphid population was negative and low (-0.4939 and -0.2628, respectively) while it was positive and moderate (0.5443) by mean temperature. The direct effect of morning relative humidity was positive and very high (1.8615), while mean relative humidity exhibited negatively very high direct effect (-3.3158) on aphid population. Residual value indicated that all these biotic and abiotic factors had a total combined effect of 86.01 per cent on population build-up of mustard aphid. It indicated that only 13.99 per cent effect was through other unknown factors existing in the ecosystem during both seasons.

Nematode resistance protein HSPRO2 of Arabidopsis thaliana has important roles in defence response to the bacterium (Pseudomonas syringae) and shows response against oxidative stress and salicylic acid. We have explored the gene encoding it from Rorippa indica (L.) Hiern, a wild relative of cultivated crucifers experimentally challenged with mustard aphid Lipaphis erysimi. The gene seems to be a strong candidate for aphid tolerance in cultivated mustards. Presently we are reporting the results of a time-course quantitative relative expression analysis of HSPRO2 of R. indica where we have observed ~ tenfold increase in its expression in R. indica at 12 hours post infestation with L. erysimi. We have also isolated the full-length gene (1314 bp) by both 5′ and 3′ RACE (Rapid Amplification of cDNA Ends). Genome walking experiment identified the promoter sequence. Expression, purification and characterisation of RiHSPRO2 showed that it encodes for a 437 amino acid peptide. The 66 kDa recombinant RiHSPRO2 protein was purified for studying its efficacy against L. erysimi in an artificial diet-based insect bioassay that revealed LC50 (Lethal Concentration 50) values of RiHSPRO2 significantly within limits against L. erysimi. The present study might have a significant implication in future towards aphid management program of Brassica juncea through the development of aphid-tolerant transgenic plants. [ABSTRACT FROM AUTHOR]

Insect damage leads to changes in biochemical profile of plants. Response of three Brassica juncea-fruticulosa introgression lines (already reported resistant to Lipaphis erysimi) in terms of changes in biochemical constituents after aphid infestation was studied along with B. fruticulosa (resistant parent), B. juncea var. PBR −210 (susceptible parent) and B. rapa ecotype brown sarson BSH-1 (susceptible check). These six genotypes were grown under aphid infested and uninfested conditions and were sampled at peak aphid infestation to analyze the biochemical changes caused by aphid feeding from top 10 cm central twig of plant. A significant reduction in glucosinolates content in aphid infested plants of three introgression lines (I8, I79 and I82) was observed while opposite was observed in B. fruticulosa, PBR-210 and BSH-1. Exactly opposite trend was observed for total phenols where aphid infestation resulted in significant increase in phenols content in the three introgression lines while a decrease was observed in B. fruticulosa, PBR-210 and BSH-1. A general trend of decline in flavonols, total sugars and free amino acids content was observed after aphid infestation in all the genotypes. Glucosinolates and total phenols served as biochemical bases of resistance in the three introgression lines since there was downregulation of glucosinolates and upregulation of total phenols as against opposite trend observed in BSH-1 and PBR-210. [ABSTRACT FROM AUTHOR]

An attempt has been made to quantify the effect of weather parameters and ladybird beetle on population fluctuation of aphid using path analysis of data collected during rabi 2012-13 and 2013-14 at Junagadh Agricultural University, Junagadh. The result revealed that the direct effect of minimum and maximum temperatures on aphid population was negative and low (-0.4939 and -0.2628, respectively) while it was positive and moderate (0.5443) by mean temperature. The direct effect of morning relative humidity was positive and very high (1.8615), while mean relative humidity exhibited negatively very high direct effect (-3.3158) on aphid population. Residual value indicated that all these biotic and abiotic factors had a total combined effect of 86.01 per cent on population build-up of mustard aphid. It indicated that only 13.99 per cent effect was through other unknown factors existing in the ecosystem during both seasons. [ABSTRACT FROM AUTHOR]