Susceptible Reaction Research Articles

Reaction of Gidami Coffee Collections against the Major Diseases

Ethiopia's largest export commodity is coffee arabica, one of the most significant goods that significantly contribute to the national economy. However, diseases including coffee berry, coffee leaf rust, and coffee wilt have been significantly reducing its yield. In order to assess Gidami coffee arabica accessions’ reaction to serious fungal infections, this study was started. The total of 100 genotypes was evaluated under Gera and Haru field situations for these major diseases. Whereas, 92 accessions with two checks were tested under greenhouse condition for coffee wilt. The results showed a highly significant variation (p<0.001) among genotypes in both conditions with 0–51%, 4–36%, and 0–100% disease severity ranges respectively. Except the four accessions namely G67/13, G71/13, G54/13, and G66/13, most of them showed susceptible reactions to CBD under Gera conditions. As well, 36 and 12 coffee accessions revealed <10% CLR reactivity at Haru and Gera conditions respectively. But none of the accessions had resistance levels higher than the two checks (Challa and 8136) at either of the locations. In other word, Gera had much greater levels of CBD and CLR pressure than Haru. On the other hand, only two accessions, G57 and G20, showed 100% CWD survival rate in greenhouse environments. This study showed how plant genetics and environmental variables affect diseases development and demonstrated that the response of Gidami coffee accessions to the major coffee diseases highly influenced by geographical and genetic variables. Therefore, continual and massive genotype screening across the locations must be taken into account in order to get resistance genotypes as the best disease mitigation to overcome the coffee diseases problem.

Phenotypic and genotypic evaluation of Turkish bread wheat (Triticum aestivum L.) varieties to stripe rust (Puccinia striiformis f.sp. tritici)

AbstractWheat stripe rust, which is caused by the basidiomycetes fungal pathogen Puccinia striiformis f.sp. tritici (Pst), is one of the most destructive diseases of wheat in Türkiye and worldwide. In this study, a total of 99 bread wheat varieties were assessed at the adult plant stage under natural infection conditions during the 2021–2022 and 2022–2023 growing seasons. Additionally, specific molecular markers were used to genotype the stripe rust resistance genes Yr26, Yr32, Yr36, Yr44 and YrSP. Disease severity was determined using the modified Cobb scale and infection reactions of each bread wheat varieties were evaluated, and also coefficient of infection value was calculated based on those parameters. To determine whether the wheat varieties had resistance gene(s), specific molecular markers associated with the resistance genes Yr26, Yr32, Yr36, Yr44 and YrSP were used. In the field trials, the majority of the tested varieties showed moderately susceptible and susceptible reactions in both years. According to the molecular results, they were positive for Yr32 in three varieties, Yr36 in 25 varieties, YrSP in two varieties and none of them had Yr26. Furthermore, some varieties carried combinations of these genes, such as Yr32 + Yr36, Yr32 + Yr44, Yr36 + Yr44, Yr36 + YrSP, Yr32 + Yr36 + Yr44 and Yr32 + Yr36 + Yr44 + YrSP. On the other hand, it was not determined these resistance genes in 16 varieties. In the literature, these resistance genes were first identified in Turkish bread wheat varieties. In addition, these findings are valuable for the development of wheat cultivars with effective and more durable resistance to stripe rust in Türkiye.

Distribution of Mosaic Disease in Ridge Gourd (Luffa acutangula (L.) Roxb.), Characterization of Associated Virus and Screening for Virus Resistance

Aims: A survey was conducted in the ridge gourd growing areas of Kasaragod, Kannur and Kozhikkode district, India, to assess the prevalence of virus diseases. Molecular detection and characterization indicated the presence of mixed infection of Tomato leaf curl New Delhi virus (ToLCNDV) and Cucumber mosaic virus (CMV) in infected samples of ridge gourd collected from surveyed locations. Additionally, a screening of popular varieties/hybrids was undertaken to identify resistance sources against the Begomovirus in Ridge gourd.
 Study Design: CRD design for screening for resistance genotype.
 Place and Duration of Study: Department of Plant Pathology, College of Agriculture, Padannakkad. November 2022 - 2023.
 Methodology: Twenty-five ridge gourd plants were selected from a field and scored during survey. Major weeds and insects in and around the location were collected and identified. Screening for resistance was carried out in vitro by grafting infected scion on to healthy ridge gourd plants. Begomovirus infections were confirmed by polymerase chain reaction (PCR) using specific coat protein primers. Presence of CMV was detected using specific primers.
 Results: Disease incidence (DI) of surveyed locations ranged from 5.3-100 per cent and vulnerability index (VI) from 26.57-84.08. Kunjathur, Thalangady, and Hosabettu areas of Kasaragod district recorded the highest incidence (100%). The highest VI (84.08) was recorded in Thalangady (Kasaragod). Bemisia tabaci and Aphis gossypii were the associated insects and Synedrella sp., Ageratum conizoides and Alternanthera sp. were the associated weeds.
 Screening of varieties indicated moderately susceptible reactions of RG7 and RG10 after 60 days of grafting. PCR based molecular detection of ToLCNDV using coat protein specific primers yielded amplicons of approximately 575 bp. All the isolated sequences were found to be related to ToLCNDV on sequencing and blast analysis. Phylogenetic studies revealed that isolates from Thrikaripur, Mavichery, and Poolacode were closely related to each other. Cucumber mosaic virus, a RNA virus was also detected from isolated samples using specific primers of CMV with an amplicon size of 400 bp.
 Conclusion: The study revealed that the ridge gourd cultivated in areas of Kasaragod, Kannur and Kozhikode were infected with ToLCNDV and CMV; RG7 and RG10 were moderately susceptible among the varieties and hybrids screened. The presence of the begomovirus was detected in weeds indicating its role in perpetuation and spread of the virus disease in the field.

Stem Rot of Pearl Millet Prevalence, Symptomatology, Disease Cycle, Disease Rating Scale and Pathogen Characterization in Pearl Millet-Klebsiella Pathosystem.

The oldest and most extensively cultivated form of millet, known as pearl millet (Pennisetum glaucum (L.) R. Br. Syn. Pennisetum americanum (L.) Leeke), is raised over 312.00 lakh hectares in Asian and African countries. India is regarded as the significant hotspot for pearl millet diversity. In the Indian state of Haryana, where pearl millet is grown, a new and catastrophic bacterial disease known as stem rot of pearl millet spurred by the bacterium Klebsiella aerogenes (formerly Enterobacter) was first observed during fall 2018. The disease appears in form of small to long streaks on leaves, lesions on stem, and slimy rot appearance of stem. The associated bacterium showed close resemblance to Klebsiella aerogenes that was confirmed by a molecular evaluation based on 16S rDNA and gyrA gene nucleotide sequences. The isolates were also identified to be Klebsiella aerogenes based on biochemical assays, where Klebsiella isolates differed in D-trehalose and succinate alkalisation tests. During fall 2021-2023, the disease has spread all the pearl millet-growing districts of the state, extending up to 70% disease incidence in the affected fields. The disease is causing considering grain as well as fodder losses. The proposed scale, consisting of six levels (0-5), is developed where scores 0, 1, 2, 3, 4, and 5 have been categorized as highly resistant, resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible disease reaction, respectively. The disease cycle, survival of pathogen, and possible losses have also been studied to understand other features of the disease.

Pseudocercospora fijiensis mycelia-based infection system enhances investigational efficacy of P. fijiensis-banana pathosystem

Screening procedures for black Sigatoka have limitations. Thus, there is need for alternative screening procedure. A robust controlled-environment methodology for testing reaction of banana genotypes to Pseudocercospora fijiensis is, thus, still required. The objective of this study was, therefore, to assess the effect of P. fijiensis fragmented mycelia-based inoculum on black Sigatoka development in banana under screen house conditions with the view of developing a procedure for early assessment of resistance. Black Sigatoka severity increased significantly (P < 0.05) over time in all genotypes apart from Kayinja. Significant differences (P < 0.05) in severity were also recorded among the genotypes at 3, 4, 5 and 6 weeks after inoculation. All east African highland banana and plantain genotypes tested exhibited susceptible reaction, characterized by rapid progression of symptoms to necrotic lesions. Kayinja and M9 hybrids exhibited resistant reactions, characterized by small necrotic specks and chlorotic or brown blotches, respectively. The fragmented mycelia-based infection system classified the banana genotypes into resistant and susceptible clones, making it a reliable and efficient infection technique to assess black Sigatoka disease damage. The infection system is recommended for early screening for black Sigatoka resistance.

FIELD ASSESSMENT OF PROMISING SUGARCANE GERMPLASM AGAINST WHIP SMUT DISEASE UNDER ARTIFICIAL INOCULATED CONDITION

Twenty four promising sugarcane germplasm of different maturity groups along with checks were screened against whip smut disease under artificial condition during season 2020-21 to identify sources of disease resistance at Central Sugarcane Research Station, Padegaon Maharashtra. Fourteen germplasm designated viz., Co PDN 19004, Co PDN 19007, Co PDN 19011, Co PDN 19016, Co PDN 19017, Co PDN 19025, Co PDN 19028, Co PDN 19041, Co PDN 19042, PDN 15012, CoM 11082, MS 10001, Co 86032 and CoM 0265 showed resistant reaction to smut disease while 10 genotypes exhibited moderately resistant reaction to smut disease under artificially inoculated conditions in the field. Susceptible checks Co 740 had susceptible reaction indicated much disease pressure with susceptible reaction. This resistant germplasm may be further utilized as donor for further breeding programs to evolve new resistant variety against whip smut of sugarcane.

Identification Sources of Resistance from rice Germplasm Against Sheath Rot Disease under Artificial Epiphytotic Conditions

Twenty nine entries along with three checks were screened against sheath rot disease under artificial epiphytotic conditions during Kharif 2018 and 2019 to identify sources of disease resistance under field condition. Four entries designated viz., NVSR-317, NVSR-411, NVSR-405 and Sambha mahsuri exhibited resistant reaction whereas, 23 entries viz., NVSR-348, NVSR-350, NVSR-355, NVSR-2101, NVSR-2103, NVSR328, NVSR-329, NVSR-2528, NVSR-2565, NVSR-2566, NVSR-330, NVSR-331, NVSR-335, NVSR-338, NVSR360, NVSR-364, NVSR-365, NVSR-370, NVSR-374, NVSR-384, NVSR-389, NVSR-2435 and NVSR-406 showed the moderately resistant reaction and rest of the entries were recorded moderately susceptible and susceptible in their reactions against the sheath rot disease under artificial inoculation. Both susceptible checks GR-11 and TN-1 had scale-7 indicated much disease pressure with susceptible reaction. These resistant germplasm may be further utilized as donor for further breeding programs to evolve new resistant variety against sheath rot.

Threshold dynamics of a nonlocal dispersal SIS epidemic model with free boundaries

To study the influence of the moving front of the infected interval and the spatial movement of individuals on the spreading or vanishing of infectious disease, we consider a nonlocal susceptible–infected–susceptible (SIS) reaction–diffusion model with media coverage, hospital bed numbers and free boundaries. The principal eigenvalue of the integral operator is defined, and the impacts of the diffusion rate of infected individuals and interval length on the principal eigenvalue are analyzed. Furthermore, sufficient conditions for spreading and vanishing of the disease are derived. Our results show that large media coverage and hospital bed numbers are beneficial to the prevention and control of disease. The difference between the model with nonlocal diffusion and that with local diffusion is also discussed and nonlocal diffusion leads to more possibilities.

Identification of Resistant and Susceptible Sources against Blast Diseases in Finger Millet [Eleusine coracana L. (Gaertn.)

The study was undertaken to evaluate the 490 finger millet (Eleusine coracana L.) genotypes (released, pre-release and breeding genotypes) including two check varieties viz., Indaf 5 (susceptible) and GPU-28 (resistant) against neck and finger blast disease at Hill Millet Research Station, Waghai, The Dangs, Gujarat during kharif, 2018 to 2022. Among all the 490 genotypes, 148 genotypes have shown resistant reaction under high disease pressure field conditions for neck and finger blast disease. However, 44 germplasm genotypes have shown consistent susceptible reaction during five years tested viz; kharif, 2018 to 2022. The genotypes viz., CFMV 2, GN-8, VL-376, PR-202 and GPU-67, showed the higher immune reaction under natural field condition. The pooled percent disease intensity of neck and finger blast diseases ranged from 2.90 to 72.4 per cent and 3.9 to 84.2 per cent respectively, in all tested genotypes including national and local checks. The resistant check variety GPU-28 exhibited resistant reaction to both neck and finger blast. In susceptible check variety Indaf-5 recorded the pooled diseases intensity of 61.74 % for neck blast and 73.6 % for finger blast. In which 72.4 and 84.2 is the highest percent pooled disease intensity of neck and finger blasts recorded in finger millet entry WN 666 which is the most highly susceptible reaction noted across five years of study in blast susceptible zone of Gujarat.

Screening of Rice Genotypes for Bacterial Blight of Rice Under Artificial Inoculation Method and Monitoring Field Virulence of Xanthomonas oryzae pv. oryzae

The present study was conducted at the main rice research centre, Navsari Agricultural University, Navsari, Gujarat, India during kharif (July–November, 2020) to study the screening of rice genotypes for bacterial blight of rice under artificial inoculation method and monitoring field virulence of Xanthomonas oryzae pv. oryzae. Thirty genotypes along with two susceptible checks against bacterial blight pathogen under artificial inoculation condition revealed that, 3 genotypes were found moderately resistant viz., NVSR-466, NVSR-396 and ISM. Whereas, 12 genotypes viz., NVSR-411, NVSR-443, NVSR-447, NVSR-453, GNR-6, IR-28, NAUR-1, GNR-2, Gurjari, GNR-4, Krishna kamod and GAR-13 were found susceptible to Xoo and two checks viz., GR-11 and TN-1 were found highly susceptible. Observing to the disease severity, by screening 29 IRBB differentials and two checks employed for research on monitoring virulence of Xoo. Out of 29 differentials, 3 entries were found resistant viz., IRBB-53, IRBB-57 and IRBB-60. Whereas, 3 entries viz., IRBB-50, IRBB-52 and IRBB-61 were moderately susceptible reaction and all the single genes possessing entries were found susceptible to Navsari isolates of Xoo. The goal of this study provided valuable insights to determine the potential management strategies for the disease in rice crops by employing methodology of two rows of 2 meters in length for each entry, the susceptible check TN-1 and GR-11 were planted after the 10th test entry for screening of rice genotypes and monitoring the field virulence of Xoo.

Reaction of safflower breeding lines to Fusarium wilt

Fusarium wilt (Fusarium oxysporum f. sp. carthami) is an important disease of safflower, causing 90% yield loss. The pathogen, being mainly soil-borne, is quite difficult to manage using conventional methods. Keeping this in view, the current study was conducted to identify the resistant breeding lines against wilt. A total of 30 multiparent cross-based breeding lines were screened in wilt sick pot and the results revealed that 29 lines were found immune, while one line showed a moderately susceptible reaction to wilt. These breeding lines can be further used in the resistance breeding programme to develop resistant varieties.

Variability in bacterial endophytes in leaves of transgenic Bt and non-Bt cotton crop varieties and their role in suppression of bacterial leaf blight pathogen X. a. pv. malvacearum and the incited disease reaction

Microbial epiphytes and endophytes are an integral part of the plant system and are known to play various roles in crop growth and crop health management. The transgenic crop plays an important role in crop pest management, however, environmentalists and ecologists have reservations about the cultivation of these crops. Whether the transgenic Bt cotton and non-Bt cotton vary in their microbial habitat ecology is not yet studied. In the present investigations, the leaf endophytic bacteria were detected in the leaves of both transgenic Bt and non-Bt cotton hybrids. However, there were differences in the endophytic bacterial types and their population densities i.e. bacterial colony-forming units (cfu) in the leaves of Bt and non-Bt cotton varieties. At least ten different leaf endophytic bacteria were detected from two cotton varieties i.e. RCH-2 and Bunny (of transgenic Bt and non-Bt versions). A maximum of four types of leaf endophytic bacteria was present in RCH-2 Bt cotton leaves. The population density of leaf endophytic bacteria ranged from 50 cfu/leaf to 5 x 103 cfu/leaf and varied with individual leaf endophyte and cotton variety. These bacterial leaf endophytes were observed to inhibit or suppress the growth of bacterial leaf blight pathogen Xanthomonas axonopodis pv. malvacearum (Xam) under in-vitro test. Leaf endophyte no.7 was more effective followed by leaf endophyte no.4 in suppressing the Xam population and population of other endophytes in the interaction studies. Interaction of leaf endophytes and Xam in cotton leaves suggested that endophytes of transgenic Bunny-Bt were effective on Xam in transgenic Bunny–Bt hybrid only and so these changed the induction of susceptible water-soaking disease reaction into hypersensitive browning resistance reaction (HR). However, these endophytes of Bt-cotton were not effective in the non-Bt version in changing the susceptible reaction of Xam into an HR reaction. This indicated that the endophytes of the respective Bt and non-Bt crops were able to change the susceptible reaction of Xam into a hypersensitive one in their respective host, indicating that the use of leaf endophytes can be effective in their own habitat crop as a biocontrol agent against Xam. The specificity of leaf endophytes has to be considered in biological disease management programs.

Screening of onion (Allium cepa) genotypes to find out novel resistant source against purple blotch (Alternaria porri)

Purple blotch caused by Alternaria porri (Ellis) Cif., 1930 causes huge losses to bulb crop and seed crop of onion (Allium cepa L.). This is a major disease affecting successful onion production in majority of the onion growing areas. To identify resistant source against purple blotch, 34 onion genotypes with good marketable yield based on field evaluation trial in 2017 and allied species Pusa Soumya were screened under protected conditions during kharif, 2018 at insect proof net house facility of ICAR-Indian Agricultural Research Institute, New Delhi. The pure culture of Alternaria porri, isolated from infected leaf samples of onion crop raised under natural epiphytotic conditions during kharif, 2017. Highest change of disease severity index was observed between 1–2 weeks post inoculation (WPI) while highest disease severity index was recorded at 5 WPI suggesting that preventive measures must be employed as soon as disease symptoms appear in the field. The disease severity index ranged from 0.10–33.33 at 1 WPI, which increased to 9.33–89.33 at 5 WPI. The cultivated allied species Pusa Soumya was identified as novel resistance source with DSI value less than 10.0% at 5 WPI. Four genotypes exhibited moderately susceptible reaction, while 20 genotypes were susceptible and 10 genotypes were highly susceptible. The area under disease progress curve (AUDPC) value ranged from 22.33–240.17. Pusa Soumya had the lowest value and among onion lines Arka Kirtiman was found promising. Three onion genotypes had low relative AUDPC value and can effectively be utilized in resistance breeding programme. The average daily temperature between 20–25°C and relative humidity above 75% was found ideal for disease development.

Need for disease resistance breeding against Corynespora cassiicola in crops

Corynespora cassiicola (Cc) is a genetically diverse ascomycete found worldwide in tropical and subtropical regions. Cc causes necrotrophic diseases in several plant species, including important crops such as rubber tree, tomato, cotton, and cucumber. Evidence suggests the involvement of one or more Cc host-specific toxins in disease progression. Management of Cc crop diseases is based mainly on pesticide sprays. However, the pathogen’s development of resistance to commonly used fungicides is documented. Resistance breeding is an attractive alternative or supplement to chemical control of Cc crop diseases, but research on this topic is very limited. This review describes the current plant resistance breeding efforts towards Cc resistance and discusses the potential influence of host-specific toxins (HSTs) on such efforts. Although some reports of host resistance exist in a few crops, resistant germplasm and knowledge about resistance mechanisms are limited. Some studies have suggested the involvement of HSTs in disease development, including the upregulation of resistance-related proteins in susceptible reactions and the recessive nature of resistance. In light of this, host resistance may not be achieved through commonly used dominant R-genes.

The challenge of managing yellow rust (Puccinia striiformis f.sp. tritici) in winter wheat: how combined climate and pathogen stressors impact variability in genotype reactions

Despite the ongoing evolution of wheat pathogens due to the selection pressures of agro-ecological conditions, many studies have often overlooked the combined impact of both biotic and abiotic factors on disease occurrence. From 2016 to 2023, a comprehensive screening of obligate pathogens, including B. graminis f. sp. tritici, P. graminis f. sp. tritici, P. triticina, and P. striiformis f. sp. tritici, was carried out. This screening was conducted on a phenotyping platform encompassing 2715 winter wheat genotypes and their wild relatives, both with and without resistant genes (Lr, Yr, and Sr) for rust diseases. The data were analyzed using PCAmix, best subsets regression, and linear regression modeling. The findings from this study reveal that the plant reactions to leaf and yellow rust infections is far from straightforward. It is heavily influenced not only by prevalent rust races and climatic factors that impact pathogen life cycles but also by variations in the susceptibility reactions of wheat genotypes to the broader agro-ecological conditions. We also observed a tendency for leaf rust and yellow rust to coexist within the same host plant, even though yellow rust is typically considered more aggressive. We reported for the first time genes related to yellow rust resistance breakdown in Serbia in 2023. Lastly, we underscored the importance of investigating resistance responses to rust diseases not exclusively through the interrelation between resistance genes and pathogen virulence, but also by considering how plants respond to the combined stresses of abiotic and biotic factors. Consequently, our study sets the groundwork for further research into how plants respond to multiple stressors and contributes for further investigations related with effective integrated rust management.

Genetic diversity and resistance assessment among maize genotypes against banded leaf and sheath blight (caused by Rhizoctonia solani f. sp. sasakii) utilizing SSR markers

AbstractA field investigation was carried out during the consecutive kharif seasons of 2021 and 2022 to assess the resistance response of 38 maize genotypes against banded leaf and sheath bight (BLSB). The trials were conducted at CCS Haryana Agricultural University, Regional Research Station, Karnal (India) under artificial epiphytotic conditions. Throughout both seasons, six genotypes (HKI 163, HKI 193‐2, HKI 488, IQPMH‐18‐2, HKI 194‐7 and HKI 1128) exhibited resistant reactions, one genotype (HM 8) showed susceptible reaction, whereas 19 genotypes showed moderately resistant response to BLSB. To analyse molecular aspects of BLSB resistance, genomic DNA was extracted and PCR amplification was performed using 22 SSR markers. Ten SSR markers (bnlg238, bnlg161, bnlg127, bnlg339, bnlg615, bnlg1272, phi077, phi080, phi035 and umc1275) revealed distinct banding patterns in resistant and susceptible genotypes. Among these, marker bnlg339 exhibited a band size of 120 bp across 14 genotypes, with six (HKI 163, HKI 193‐2, HQPM 5, IQPMH‐18‐2, HKI 194‐7 and HKI 1128) classified as resistant and eight (HKI 193‐1, HKI 1657, HKI 1378, HPQM 1, HKI 1659, HPQM 2, T Bio 259 ER and HKI 191‐2‐5) as moderately resistant, resembling the amplified profile of the resistant check genotype (HKI 163). Similarly, the markers phi080 and bnlg1272 exhibited differential amplified profile of approximately 150 bp and 240 bp, respectively, in 10 (five resistant and five moderately resistant) and 12 (four resistant and eight moderately resistant) maize genotypes throughout the study. The percentage of polymorphism for the SSR markers varied from 0 to 100%, with an average value of 95.45% per primer among all genotypes. The identification of resistant and moderately resistant genotypes and characterization of specific SSR markers associated with resistance offer practical tools for breeders to develop BLSB‐resistant maize varieties, ultimately enhancing crop resilience and food security.

Interaction of chromium-sulfur-iron during Cr(VI) stabilization by polysulfide-modified nanoscale zero-valent iron for groundwater remediation: Batch experiments and numerical simulation

Sulfidated nano zero-valent iron (nZVI) is a vital technology for stabilizing hexavalent chromium (Cr(VI)) in groundwater. However, it faces challenges such as oxidation susceptibility and unclear reaction mechanisms. In this study, a novel CaSx-modified nZVI material (PS-nZVI) was synthesized through an improved preparation method by using a two-step method to investigate its interactions with chromium, sulfur and iron for Cr(VI) immobilization. Results showed that the addition of PS significantly altered the microstructure and properties of the material. As the PS content increased, the material transformed from nZVI to a flower-like FeSn structure, enhancing its reduction capability and protecting the internal nZVI. PS-nZVI exhibited higher Cr(VI) removal capacity compared to nZVI, with the best efficiency at a PS/Fe molar ratio of 1/10. The removal process followed a pseudo-second-order kinetic model, indicating that chemical adsorption dominated. Initially, PS-nZVI focused on reducing Cr(VI), differentiating it from other sulfide-modified nZVI. The formation of FeSn on the surface of material facilitated the reduction of Fe(III) and Cr(VI) and acted as an electron transfer intermediate, enabling efficient Cr(VI) stabilization. Using a reactive transport model, it can be found that iron contributed 57.4% to Cr(VI) solidification as chromite, while sulfur and iron contributed 95.9% and 4.1%, respectively, to Cr(VI) reduction to Cr(III).

Evaluation the durable resistance of soybean varieties toward leaf rust caused by Phakopsora pachyrhizi

The main disease of soybean plants is leaf rust caused by the fungus Phakopsora pachyrhizi which can cause a decrease in the yield of up to 60% and has the potential to reduce seed quality. The use of resistant varieties is the main component of rust disease control. The purpose of this research was to determine the resistance level of several soybean varieties to the rust disease caused by Phakopsora pachyrhizi and its effect on the production of each variety. To evaluate the resistance reaction of soybean varieties to rust disease, the IWGSR system was used, as the intensity level of the disease and its effect on the production of each tested soybean variety. The results showed that the Detap 1 variety counted the lowest disease intensity of 22.84% with a susceptible disease reaction and had high productivity, followed by the Agromulyo, Anjasmoro, and Devon 1 varieties which categorized a mildly susceptible disease reaction with a disease intensity of 25.34%, 27.46%, and 28.70% respectively. The Derap 1 and Edamame varieties have a high disease intensity of 35.18% and 29.31% with susceptible disease reactions. The production of the highest number of pods was the Agromulyo variety.

Genetic response of hybrid maize line to downy mildew caused by Peronosclerospora spp. infection

Maize is the second staple food commodity in Indonesia. Apart from being the main source of carbohydrates and protein, the production of maize continues to increase along with the escalation of population growth and animal feed requirements in the last few years. The potential to increase the national production of maize is still feasible because of the yield gap between the potential yields of new superior varieties and the level of yields obtained by farmers. The yield gap caused by biotic stress in maize is mainly caused by pathogens such as downy mildew due to Peronosclerospora spp. Downy mildew distribution is sporadic that can infect a wide area. In Indonesia, it spreads widely and significantly reduces yields in the areas of maize production centres in East Java, Central Java, South Sulawesi, North Sulawesi, Gorontalo, Lampung, and Sumatera. These obstacles can be overcome by integrated pest and disease control technology. One strategy is to discover downy mildew-resistant varieties that can be combined with other control treatments. The phenomenon of resistance to downy mildew infection of several hybrid maize strains began to be detected in the vegetative growth phase, with symptoms beginning at 14 days after planting (DAP), increasing with plant age, and reaching its peak after 28-35 DAP and then the symptoms will gradually disappear until no infection after 42 HST. This study analyses the resistant maize varieties from 2020 to 2022. The data showed the susceptible comparison variety (Anoman) was infected with 88.94% to 100%. In 2020, BMD73 showed a resistant reaction to Philippinensis species, other strains were classified as susceptible in P. maydis except BMD 76. All strains showed highly susceptible and susceptible reactions. In 2021, in P. philippinensis all strains FCP10-FCP16 showed a resistant reaction, but line FCP10-FCP16 had a resistance response that was classified as moderately resistant to P. maydis. The incidence of genetic response in 2022, except BMD86, strains BMD81-BMD85 were classified as resistant, as well as in the P. maydis endemic area all strains showed the same reaction.

Brown Planthopper, Nilaparvata lugens Stål Resistance in Backcross Derived Rice Lines

A prominent rice pest, brown planthopper (BPH) significantly reduces the grain yield in rice across the globe and employing chemical pesticides leads to unwarranted environmental issues. Breeding for BPH resistance is an essential strategy to mitigate the losses caused by them. Host plant resistance through marker assisted selection is a chief strategy to lessen harms caused by BPH and boost rice production. In this study, we have analyzed BPH resistance in the BC1F5 population, which is a backcross derivative of improved CO51 and Ptb33. Improved CO51 has already been introgressed with bacterial blight resistant genes xa5, xa13 and Xa21 and blast resistant gene Pi54 via marker assisted selection (MAS). Ptb33 was used as the donor parent to incorporate BPH resistant genes bph2 and Bph32 to this CO51 background. The genotypically and phenotypically selected 26 lines of BC1F5 generation were screened against BPH along with parents and checks. The bioassay of the population exhibited a range of variation for BPH resistance. Among the 26 near isogenic lines, 18 (2 resistant and 16 are moderately resistant) and eight showed susceptible to moderate susceptible reaction. The 18 resistant lines were further multiplied and are now in hot spot screening.