Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents ...Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil.展开更多
One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote pl...One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote plant growth was investigated.The dual culture tests highlighted the strong antagonistic activity of five fungal(ranging from 89%–70%)and five bacterial(72%–61%)endophytes.Subsequent examination focused on volatile compounds produced by selected isolates to counter the blast pathogen.Among these,the highest chitinase(13.76μg mL−1)and siderophore(56.64%),was exhibited by Aspergillus flavus,and the highest HCN production was shown by Stenotrophomonas maltophilia(36.15μM mL−1).In terms of growth promotion traits,Aspergillus flavus and Enterobacter cloacae excelled in activities viz,phosphorous solubilization,ammonia production,auxin and gibberellic acid production,and nitrogen fixation.The Identity of these endophytes was confirmed through molecular analysis as Trichoderma afroharzianum,Trichoderma harzianum,Penicillium rubens,Aspergillus flavus,Stenotrophomonas rhizophila,Stenotrophomonas maltophilia,Bacillus cereus,Enterobacter cloacae,and Bacillus licheniformis.Under greenhouse conditions,the highest disease control was shown by isolate Bacillus licheniformis and A.flavus with an inhibition of 79%,followed by S.rhizophila(77%)and T.afroharzianum(73%).The overall results of this study showed that Bacillus licheniformis and Stenotrophomonas rhizophila have great potential to be used as bio-stimulant and biocontrol agents to manage rice blast disease.展开更多
Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided ...Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided in 4 lots viz., untreated (neither Ca nor HWT), Ca alone (pre-harvest 3 sprays of CaCl2 (1.0% w/v) in the orchard), HWT (42℃ for 2 h). Apples of all four lots were stored in cold storage maintained at 0℃ ± 1℃ and 90% - 95% relative humidity for 6 months. After storage, fruits were removed to ambient conditions for 5 days, and then observations on decay area and incidence, bitter pit incidence, fruit Ca content, lipoxygenase (LOX) and antioxidant (AOX) activity, fruit firmness and fruit quality parameters were recorded. After 6 months in cold storage plus 5 day at 22℃ ± 2℃ and 70% + 4% RH, apples, which received Ca as pre-harvest spray or those which received postharvest hot water treatment or Ca + HWT had significantly lesser decay area (decay lesions) caused by Penicillium expansum or Botrytis cinerea than untreated ones (control). Ca + HWT treatment was significantly more effective on B. cinerea than P. expansum. Untreated apples exhibited higher incidence of bitter pit (18.2%) than those treated with Ca or HWT or both. Fruit Ca content (2.92% DM) were significantly lower and conversely the LOX activity (6.9 μmoles min–1×g–1FW) was higher in untreated apples. Similarly, total phenolics and AOX activity were also lower in the untreated apples than Ca or HWT treated. HWT or Ca treated apples have beneficial effects on fruit firmness, peel colour and quality parameters like TSS and ascorbic acid content. Thus, it is concluded that pre-harvest sprays of calcium chloride with postharvest HWT is highly useful for “Royal Delicious” for reducing decay loss, maintaining firmness, high levels of antioxidants and fruit quality.展开更多
An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced...An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced in the research station of North Bengal Agricultural University (27.06°N 88.47°E) situated in north eastern Himalayan region of Darjeeling district in the state of West Bengal from Sikkim Sangtok (27°25'N 88°31'E) of north Sikkim area in India for the purpose of conservation. As we noticed some irregular development of floral organs, we investigated some pertinent questions regarding ecological aberrations found in plants. We found plants introduced in north eastern Himalayan region changed their homology of number flower petals and position of stamens seen naturally in north western Himalayan region as per the reports. Was there any genetic or extreme environmental stress condition caused a sudden change in floral structure as it is generally known as a rare phenomenon and frequently not seen? What were the correlations of different floral parts and fitness of population in different morphotypes? We predicted possible outcomes of seed setting by univariate regression models in a particular environment in addition to this investigation. We proposed three models of heterozygousity for answering the reasons of unstable floral form from a general known floral form, where silent mutations help the plants to survive in adverse conditions in spite of deformed or variable formed of floral morphology.展开更多
Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been int...Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been introduced into some African countries in recent years to improve CGM control was followed with specific PCR assays.Two primer pairs,展开更多
Evaluation of various fungicides against needle blight disease of pine was carried out at Shed Kashmir University of Agriculture Sciences and Technology of Kashmir (India) during the year 2008 and 2009. Applica- tio...Evaluation of various fungicides against needle blight disease of pine was carried out at Shed Kashmir University of Agriculture Sciences and Technology of Kashmir (India) during the year 2008 and 2009. Applica- tion of various fungicides were evaluated in vivo at dif- ferent concentrations. However in both, mist-chamber and poly-chamber, the Blue pine (Pinus wallichiana Jackson) seedlings treated with hexaconazole 5EC (@ 0.03 %) or carbendazim 50WP (@ 0.1%) depicted significantly less disease incidence and intensity. The seedlings treated with mancozeb 75WP (@ 0.3 %) and chlorothalonil 75WP (@ 0.3 %) exhibited less disease incidence and intensity. Increase in relative humidity from 60 to 100 % signifi- cantly enhanced needle blight disease incidence and intensity. In field trial the fungitoxicants used either as single spray or protectant followed by systemic fungitoxi- cant spray significantly reduced disease incidence in Blue pine compared to check. The mean disease incidence in fungitoxicant treated plants varied from 11.82 to 25.51% as compared to 36.03 % in control.展开更多
Coorg mandarin is a famous ecotype of mandarin grown in multi-tier cropping system in coffee and pepper plantations in Coorg region of India. The roving survey indicated disease incidence of Huanglongbing (HLB) and ...Coorg mandarin is a famous ecotype of mandarin grown in multi-tier cropping system in coffee and pepper plantations in Coorg region of India. The roving survey indicated disease incidence of Huanglongbing (HLB) and Phytophthora, ranging between 35%-64.2% and 22.5%-35.6% in different places of Coorg region. A total of 177 Phytophthora infected (plant roots 59, soil 118), and 576 greening or HLB infected Coorg mandarin samples were collected from 184 Coorg mandarin orchards, of these I II Phytophthora isolates were isolated and characterized in this study on the basis of colony growth patterns and morphological structures. Based on the virulence, only 52 of 111 Phytophthora isolates were amplified by PCR using universal internal transcriber spacer (ITS) primers, cloned and sequenced. The sequences analysis of Phytophthora isolates revealed more than 97% nucleotide (nt) similarity within themselves, except eight isolates ofP. palmivora and four isolates ofP. nicotianae had varied nt identity (70.6% to 97.4%) with other Phytophthora species compared. Similarly, 523 of 576 Coorg mandarin samples were confirmed the presence of HLB infection by PCR using 16S rRNA gene specific universal primers. The representative five of 523 Coorg mandarin isolates showed nt identity ranged from 94.4% to 95.3% with Candidatus Liberibacter asiaticus (AB008366) isolate infecting citrus in Asia and one isolate of HLB shared nt identity of 96.9% with Ca. L. asiaticus (KJ944269).展开更多
Bacterial wilt complex disease of tomato(Solanum lycopersicum L.)was incited jointly by bacterial wilt pathogen Ralstonia solanacearum and Meloidogyne incognita worldwide.Bio-efficacy of bacterial antagonists i.e.B.am...Bacterial wilt complex disease of tomato(Solanum lycopersicum L.)was incited jointly by bacterial wilt pathogen Ralstonia solanacearum and Meloidogyne incognita worldwide.Bio-efficacy of bacterial antagonists i.e.B.amyloliquefaciens DSBA-11 and P.fluorescens DTPF-3 was studied against the wilt disease complex in tomato at National Phytotran facility Indian Agricultural Research Institute(IARI),New Delhi,at 26±2°C.Minimum wilt disease incidence(26.00%)with the highest bio-control efficacy(64.15%),less juvenile population(19.33 J2/g of soil)of M.incognita was recorded in the combined application of DTPF-3+DSBA-11 after 30 d of inoculation under glasshouse conditions.In a field study,minimum bacterial wilt disease incidences 19.0%and 20.4%were recorded in the bleaching powder treatment followed by mixed application of DSBA-11+DTPF-3,19.6%and 21.2%wilt incidence in 2014 and 2015 respectively.However,a reduction of root-knot gall index was recorded a maximum of 59.76%and 69.62%in DSBA-11+DTPF-3 treated plants followed by 54.88%and 60.13%over control in DTPF-3 treatment in 2014 and 2015 respectively.The yield of tomato fruit was increased over control by 17.48%and 16.97%in 2014 and 2015 respectively under field conditions.A combination of P.fluorescens DTPF-3+B.amyloliquefaciens DSBA-11 suppressed bacterial wilt and root-knot diseases and also increased the yield of the tomato fruit significantly(p<0.05)under field conditions.展开更多
Identification of quantitative trait loci(QTLs)controlling yield and yield-related traits in rice was performed in the F_(2) mapping population derived from parental rice genotypes DHMAS and K343.A total of 30 QTLs go...Identification of quantitative trait loci(QTLs)controlling yield and yield-related traits in rice was performed in the F_(2) mapping population derived from parental rice genotypes DHMAS and K343.A total of 30 QTLs governing nine different traits were identified using the composite interval mapping(CIM)method.Four QTLs were mapped for number of tillers per plant on chromosomes 1(2 QTLs),2 and 3;three QTLs for panicle number per plant on chromosomes 1(2 QTLs)and 3;four QTLs for plant height on chromosomes 2,4,5 and 6;one QTL for spikelet density on chromosome 5;four QTLs for spikelet fertility percentage(SFP)on chromosomes 2,3 and 5(2 QTLs);two QTLs for grain length on chromosomes 1 and 8;three QTLs for grain width on chromosomes1,3 and 8;three QTLs for 1000-grain weight(TGW)on chromosomes 1,4 and 8 and six QTLs for yield per plant(YPP)on chromosomes 2(3 QTLs),4,6 and 8.Most of the QTLs were detected on chromosome 2,so further studies on chromosome 2 could help unlock some new chapters of QTL for this cross of rice variety.Identified QTLs elucidating high phenotypic variance can be used for marker-assisted selection(MAS)breeding.Further,the exploitation of information regarding molecular markers tightly linked to QTLs governing these traits will facilitate future crop improvement strategies in rice.展开更多
Change in global climate is primarily due to rising concentrations of greenhouse gases in the atmosphere that is mostly caused by human activities.The important factors affecting the occurrence and spread of the plant...Change in global climate is primarily due to rising concentrations of greenhouse gases in the atmosphere that is mostly caused by human activities.The important factors affecting the occurrence and spread of the plant diseases are temperature,moisture,light,and CO_(2) concentration.These factors cause physiological changes in plants that result in increase in intensity of crop diseases.Climate change causes a significant impact on germination,reproduction,sporulation and spore dispersal of pathogens.Climate change affects all life stages of the pathogen as well as its host to cause impact on host-pathogen interaction which facilitates the emergence of new races of the pathogen ultimately breakdowns the host resistance.It also affects the microbial community in the soil which is beneficial to the plants in various aspects.The minor diseases become major ones due to alteration in climatic parameters thus posing a threat to the food security.展开更多
Investigations were done to obtain potential phosphate solubilising strains from endophytic mycoflora isolated from the orchid,Pomatocalpa decipiens.928 endophytic phosphate solubilising fungal isolates were obtained ...Investigations were done to obtain potential phosphate solubilising strains from endophytic mycoflora isolated from the orchid,Pomatocalpa decipiens.928 endophytic phosphate solubilising fungal isolates were obtained from 2400 leaf segments(0.38%recovery)from rare epiphytic orchid Pomatocalpa decipiens present in the Barbara hills of Odisha(India).A number of isolates belonged to different genera such as Paecilomyces,Curvularia,Aspergillus,Cladosporium,Penicillium,Colletotrichum,while others,which were unidentified were classified as mycelia sterilia.Root sampling done from 25 different sites resulted in isolation of 20 endophytic phosphate solubilising fungal isolates from 300 segments(0.1%recovery).Aspergillus,Paecilomyces,Fusarium,Penicillium,and mycelia sterilia were mostly obtained.The qualitative and quantitative assessments of Phosphate(P)solubilisation were performed using TCP and Rock phosphate as P source for those strains.Aspergillus niger(leaf isolate)showed a maximum of 33.2 and 22.7%solubilisation in presence of TCP and Rock phosphate respectively whereas Aspergillus niger(Root isolate)showed a maximum of about 23.9%and 36.2%solubilisation in presence of TCP and Rock phosphate respectively.展开更多
Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving ...Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitelfy species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. Al the haplotypes detected in the study could be assigned to these three cryptic species fol owing the species demarcation criteria of 3.5%divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu-tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a signiifcantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitelfy species in India and yel ow mosaic disease observed during sampling survey.展开更多
We have studied the genotoxic and apoptotic potential of ferric oxide nanoparticles(Fe_2O_3-NPs) in Raphanus sativus(radish).Fe_2O_3-NPs retarded the root length and seed germination in radish.Ultrathin sections o...We have studied the genotoxic and apoptotic potential of ferric oxide nanoparticles(Fe_2O_3-NPs) in Raphanus sativus(radish).Fe_2O_3-NPs retarded the root length and seed germination in radish.Ultrathin sections of treated roots showed subcellular localization of Fe_2O_3-NPs,along with the appearance of damaged mitochondria and excessive vacuolization.Flow cytometric analysis of Fe_2O_3-NPs(1.0 mg/m L) treated groups exhibited 219.5%,161%,120.4% and 161.4% increase in intracellular reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),nitric oxide(NO) and Ca2+influx in radish protoplasts.A concentration dependent increase in the antioxidative enzymes glutathione(GSH),catalase(CAT),superoxide dismutase(SOD) and lipid peroxidation(LPO) has been recorded.Comet assay showed a concentration dependent increase in deoxyribonucleic acid(DNA) strand breaks in Fe_2O_3-NPs treated groups.Cell cycle analysis revealed 88.4% of cells in sub-G1 apoptotic phase,suggesting cell death in Fe_2O_3-NPs(2.0 mg/m L) treated group.Taking together,the genotoxicity induced by Fe_2O_3-NPs highlights the importance of environmental risk associated with improper disposal of nanoparticles(NPs) and radish can serve as a good indicator for measuring the phytotoxicity of NPs grown in NP-polluted environment.展开更多
Kinnow mandarin is a high value citrus crop in the fruit industry.However,the fruits are vulnerable to a variety of phytopathogens and suffer huge quantitative and qualitative losses.Pathogenic filamentous fungi like ...Kinnow mandarin is a high value citrus crop in the fruit industry.However,the fruits are vulnerable to a variety of phytopathogens and suffer huge quantitative and qualitative losses.Pathogenic filamentous fungi like Penicillium digitatum,Penicillium italicum,and Geotrichum candidum are mainly responsible for postharvest losses.Alternative to synthetic fungicides,the bacteria and yeast-based biocontrol approaches are the most efficient means for controlling postharvest diseases.The antagonistic potential of five biocontrol agents such as Debaryomyces hansenii,Lactobacillus plantarum,Metschnikowia pulcherima,Pichia guilliermondi and Rhodotorula minuta var.minuta was assessed under both in vitro and in vivo conditions against the mycelial growth of postharvest pathogens using dual culture method.The results revealed that R.minuta var.minuta was the most promising antagonist with 71.98%,76.18%and 67.46%mean mycelial growth inhibition of P.digitatum,P.italicum and G.candidum respectively,over untreated potato dextrose agar(PDA)plates after 192 h of incubation under in vitro.Further,under in vivo,the fruits treated with R.minuta var.minuta did not impair the quality and sensory attributes during ambient storage.Hence,R.minuta var.minuta proved an eco-friendly and safer substitute to synthetic fungicides for postharvest disease management of Kinnow mandarin fruits.展开更多
Xanthomonas axonopodis pv. punicae (Xap) causing bacterial blight is an important pathogen that incurs significant losses to the exportability of pomegranate. Xap uses the Xop TTSS-effector, via the type three secre...Xanthomonas axonopodis pv. punicae (Xap) causing bacterial blight is an important pathogen that incurs significant losses to the exportability of pomegranate. Xap uses the Xop TTSS-effector, via the type three secretion system, to suppress pomegranate immunity. Here, we investigate the role of XopL during blight pathogenesis. We observed that XopL is essential for its in planta growth and full virulence. Leaves inoculated with Xap AxopL produced restricted water-soaked lesions compared to those inoculated with wild-type Xap. XopL supports Xap for its sustained multiplication in pomegranate by suppress- ing the plant cell death (PCD) event. We further demon- strated that XopL suppresses immune responses, such as callose deposition and production of reactive oxygen species (ROS). RT-qPCR analysis revealed that immune responsive genes were upregulated when challenged with Xap AxopL, whereas upregulation of such genes was compromised in the complemented strain containing the xopL gene. The transiently expressed XopL::EYFP fusion protein was local- ized to the plasma membrane, indicating the possible site of its action. Altogether, this study highlights that XopL is an important TTSS-effector of Xap that suppresses plant immune responses, including PCD, presumably to support the multiplication of Xap for a sufficient time-period during blight disease development.展开更多
文摘Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil.
基金The authors extend their appreciation to the Researchers Supporting Project Number(RSP2023R298),King Saud University,Riyadh,Saudi Arabia.
文摘One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote plant growth was investigated.The dual culture tests highlighted the strong antagonistic activity of five fungal(ranging from 89%–70%)and five bacterial(72%–61%)endophytes.Subsequent examination focused on volatile compounds produced by selected isolates to counter the blast pathogen.Among these,the highest chitinase(13.76μg mL−1)and siderophore(56.64%),was exhibited by Aspergillus flavus,and the highest HCN production was shown by Stenotrophomonas maltophilia(36.15μM mL−1).In terms of growth promotion traits,Aspergillus flavus and Enterobacter cloacae excelled in activities viz,phosphorous solubilization,ammonia production,auxin and gibberellic acid production,and nitrogen fixation.The Identity of these endophytes was confirmed through molecular analysis as Trichoderma afroharzianum,Trichoderma harzianum,Penicillium rubens,Aspergillus flavus,Stenotrophomonas rhizophila,Stenotrophomonas maltophilia,Bacillus cereus,Enterobacter cloacae,and Bacillus licheniformis.Under greenhouse conditions,the highest disease control was shown by isolate Bacillus licheniformis and A.flavus with an inhibition of 79%,followed by S.rhizophila(77%)and T.afroharzianum(73%).The overall results of this study showed that Bacillus licheniformis and Stenotrophomonas rhizophila have great potential to be used as bio-stimulant and biocontrol agents to manage rice blast disease.
文摘Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided in 4 lots viz., untreated (neither Ca nor HWT), Ca alone (pre-harvest 3 sprays of CaCl2 (1.0% w/v) in the orchard), HWT (42℃ for 2 h). Apples of all four lots were stored in cold storage maintained at 0℃ ± 1℃ and 90% - 95% relative humidity for 6 months. After storage, fruits were removed to ambient conditions for 5 days, and then observations on decay area and incidence, bitter pit incidence, fruit Ca content, lipoxygenase (LOX) and antioxidant (AOX) activity, fruit firmness and fruit quality parameters were recorded. After 6 months in cold storage plus 5 day at 22℃ ± 2℃ and 70% + 4% RH, apples, which received Ca as pre-harvest spray or those which received postharvest hot water treatment or Ca + HWT had significantly lesser decay area (decay lesions) caused by Penicillium expansum or Botrytis cinerea than untreated ones (control). Ca + HWT treatment was significantly more effective on B. cinerea than P. expansum. Untreated apples exhibited higher incidence of bitter pit (18.2%) than those treated with Ca or HWT or both. Fruit Ca content (2.92% DM) were significantly lower and conversely the LOX activity (6.9 μmoles min–1×g–1FW) was higher in untreated apples. Similarly, total phenolics and AOX activity were also lower in the untreated apples than Ca or HWT treated. HWT or Ca treated apples have beneficial effects on fruit firmness, peel colour and quality parameters like TSS and ascorbic acid content. Thus, it is concluded that pre-harvest sprays of calcium chloride with postharvest HWT is highly useful for “Royal Delicious” for reducing decay loss, maintaining firmness, high levels of antioxidants and fruit quality.
文摘An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced in the research station of North Bengal Agricultural University (27.06°N 88.47°E) situated in north eastern Himalayan region of Darjeeling district in the state of West Bengal from Sikkim Sangtok (27°25'N 88°31'E) of north Sikkim area in India for the purpose of conservation. As we noticed some irregular development of floral organs, we investigated some pertinent questions regarding ecological aberrations found in plants. We found plants introduced in north eastern Himalayan region changed their homology of number flower petals and position of stamens seen naturally in north western Himalayan region as per the reports. Was there any genetic or extreme environmental stress condition caused a sudden change in floral structure as it is generally known as a rare phenomenon and frequently not seen? What were the correlations of different floral parts and fitness of population in different morphotypes? We predicted possible outcomes of seed setting by univariate regression models in a particular environment in addition to this investigation. We proposed three models of heterozygousity for answering the reasons of unstable floral form from a general known floral form, where silent mutations help the plants to survive in adverse conditions in spite of deformed or variable formed of floral morphology.
文摘Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been introduced into some African countries in recent years to improve CGM control was followed with specific PCR assays.Two primer pairs,
文摘Evaluation of various fungicides against needle blight disease of pine was carried out at Shed Kashmir University of Agriculture Sciences and Technology of Kashmir (India) during the year 2008 and 2009. Applica- tion of various fungicides were evaluated in vivo at dif- ferent concentrations. However in both, mist-chamber and poly-chamber, the Blue pine (Pinus wallichiana Jackson) seedlings treated with hexaconazole 5EC (@ 0.03 %) or carbendazim 50WP (@ 0.1%) depicted significantly less disease incidence and intensity. The seedlings treated with mancozeb 75WP (@ 0.3 %) and chlorothalonil 75WP (@ 0.3 %) exhibited less disease incidence and intensity. Increase in relative humidity from 60 to 100 % signifi- cantly enhanced needle blight disease incidence and intensity. In field trial the fungitoxicants used either as single spray or protectant followed by systemic fungitoxi- cant spray significantly reduced disease incidence in Blue pine compared to check. The mean disease incidence in fungitoxicant treated plants varied from 11.82 to 25.51% as compared to 36.03 % in control.
文摘Coorg mandarin is a famous ecotype of mandarin grown in multi-tier cropping system in coffee and pepper plantations in Coorg region of India. The roving survey indicated disease incidence of Huanglongbing (HLB) and Phytophthora, ranging between 35%-64.2% and 22.5%-35.6% in different places of Coorg region. A total of 177 Phytophthora infected (plant roots 59, soil 118), and 576 greening or HLB infected Coorg mandarin samples were collected from 184 Coorg mandarin orchards, of these I II Phytophthora isolates were isolated and characterized in this study on the basis of colony growth patterns and morphological structures. Based on the virulence, only 52 of 111 Phytophthora isolates were amplified by PCR using universal internal transcriber spacer (ITS) primers, cloned and sequenced. The sequences analysis of Phytophthora isolates revealed more than 97% nucleotide (nt) similarity within themselves, except eight isolates ofP. palmivora and four isolates ofP. nicotianae had varied nt identity (70.6% to 97.4%) with other Phytophthora species compared. Similarly, 523 of 576 Coorg mandarin samples were confirmed the presence of HLB infection by PCR using 16S rRNA gene specific universal primers. The representative five of 523 Coorg mandarin isolates showed nt identity ranged from 94.4% to 95.3% with Candidatus Liberibacter asiaticus (AB008366) isolate infecting citrus in Asia and one isolate of HLB shared nt identity of 96.9% with Ca. L. asiaticus (KJ944269).
文摘Bacterial wilt complex disease of tomato(Solanum lycopersicum L.)was incited jointly by bacterial wilt pathogen Ralstonia solanacearum and Meloidogyne incognita worldwide.Bio-efficacy of bacterial antagonists i.e.B.amyloliquefaciens DSBA-11 and P.fluorescens DTPF-3 was studied against the wilt disease complex in tomato at National Phytotran facility Indian Agricultural Research Institute(IARI),New Delhi,at 26±2°C.Minimum wilt disease incidence(26.00%)with the highest bio-control efficacy(64.15%),less juvenile population(19.33 J2/g of soil)of M.incognita was recorded in the combined application of DTPF-3+DSBA-11 after 30 d of inoculation under glasshouse conditions.In a field study,minimum bacterial wilt disease incidences 19.0%and 20.4%were recorded in the bleaching powder treatment followed by mixed application of DSBA-11+DTPF-3,19.6%and 21.2%wilt incidence in 2014 and 2015 respectively.However,a reduction of root-knot gall index was recorded a maximum of 59.76%and 69.62%in DSBA-11+DTPF-3 treated plants followed by 54.88%and 60.13%over control in DTPF-3 treatment in 2014 and 2015 respectively.The yield of tomato fruit was increased over control by 17.48%and 16.97%in 2014 and 2015 respectively under field conditions.A combination of P.fluorescens DTPF-3+B.amyloliquefaciens DSBA-11 suppressed bacterial wilt and root-knot diseases and also increased the yield of the tomato fruit significantly(p<0.05)under field conditions.
基金supported by the Researchers Supporting Project(RSP-2021/298),King Saud University in Riyadh,Saudi Arabia.
文摘Identification of quantitative trait loci(QTLs)controlling yield and yield-related traits in rice was performed in the F_(2) mapping population derived from parental rice genotypes DHMAS and K343.A total of 30 QTLs governing nine different traits were identified using the composite interval mapping(CIM)method.Four QTLs were mapped for number of tillers per plant on chromosomes 1(2 QTLs),2 and 3;three QTLs for panicle number per plant on chromosomes 1(2 QTLs)and 3;four QTLs for plant height on chromosomes 2,4,5 and 6;one QTL for spikelet density on chromosome 5;four QTLs for spikelet fertility percentage(SFP)on chromosomes 2,3 and 5(2 QTLs);two QTLs for grain length on chromosomes 1 and 8;three QTLs for grain width on chromosomes1,3 and 8;three QTLs for 1000-grain weight(TGW)on chromosomes 1,4 and 8 and six QTLs for yield per plant(YPP)on chromosomes 2(3 QTLs),4,6 and 8.Most of the QTLs were detected on chromosome 2,so further studies on chromosome 2 could help unlock some new chapters of QTL for this cross of rice variety.Identified QTLs elucidating high phenotypic variance can be used for marker-assisted selection(MAS)breeding.Further,the exploitation of information regarding molecular markers tightly linked to QTLs governing these traits will facilitate future crop improvement strategies in rice.
文摘Change in global climate is primarily due to rising concentrations of greenhouse gases in the atmosphere that is mostly caused by human activities.The important factors affecting the occurrence and spread of the plant diseases are temperature,moisture,light,and CO_(2) concentration.These factors cause physiological changes in plants that result in increase in intensity of crop diseases.Climate change causes a significant impact on germination,reproduction,sporulation and spore dispersal of pathogens.Climate change affects all life stages of the pathogen as well as its host to cause impact on host-pathogen interaction which facilitates the emergence of new races of the pathogen ultimately breakdowns the host resistance.It also affects the microbial community in the soil which is beneficial to the plants in various aspects.The minor diseases become major ones due to alteration in climatic parameters thus posing a threat to the food security.
基金Forest and Environment Department,Govt.of Odisha(State Plan Project)and INSPIRE programme,(No.DST/INSPIRE Fellowship/2013/506)DST,Govt.of India is gratefully acknowledged.
文摘Investigations were done to obtain potential phosphate solubilising strains from endophytic mycoflora isolated from the orchid,Pomatocalpa decipiens.928 endophytic phosphate solubilising fungal isolates were obtained from 2400 leaf segments(0.38%recovery)from rare epiphytic orchid Pomatocalpa decipiens present in the Barbara hills of Odisha(India).A number of isolates belonged to different genera such as Paecilomyces,Curvularia,Aspergillus,Cladosporium,Penicillium,Colletotrichum,while others,which were unidentified were classified as mycelia sterilia.Root sampling done from 25 different sites resulted in isolation of 20 endophytic phosphate solubilising fungal isolates from 300 segments(0.1%recovery).Aspergillus,Paecilomyces,Fusarium,Penicillium,and mycelia sterilia were mostly obtained.The qualitative and quantitative assessments of Phosphate(P)solubilisation were performed using TCP and Rock phosphate as P source for those strains.Aspergillus niger(leaf isolate)showed a maximum of 33.2 and 22.7%solubilisation in presence of TCP and Rock phosphate respectively whereas Aspergillus niger(Root isolate)showed a maximum of about 23.9%and 36.2%solubilisation in presence of TCP and Rock phosphate respectively.
基金Department of Biotechnology, Government of India for liberal funding (Functional Genomics of Yellow Mosaic Viruses of Soybean and Development of Transgenic Resistance in Soybean: BT/PR9631/AGR/02/468/2007)
文摘Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitelfy species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. Al the haplotypes detected in the study could be assigned to these three cryptic species fol owing the species demarcation criteria of 3.5%divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu-tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a signiifcantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitelfy species in India and yel ow mosaic disease observed during sampling survey.
基金funded by the National Plan for Science,Technology and Innovation(MAARIFAH)King Abdul Aziz City for Science and Technology,Kingdom of Saudi Arabia,award number 12-BIO2919-02
文摘We have studied the genotoxic and apoptotic potential of ferric oxide nanoparticles(Fe_2O_3-NPs) in Raphanus sativus(radish).Fe_2O_3-NPs retarded the root length and seed germination in radish.Ultrathin sections of treated roots showed subcellular localization of Fe_2O_3-NPs,along with the appearance of damaged mitochondria and excessive vacuolization.Flow cytometric analysis of Fe_2O_3-NPs(1.0 mg/m L) treated groups exhibited 219.5%,161%,120.4% and 161.4% increase in intracellular reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),nitric oxide(NO) and Ca2+influx in radish protoplasts.A concentration dependent increase in the antioxidative enzymes glutathione(GSH),catalase(CAT),superoxide dismutase(SOD) and lipid peroxidation(LPO) has been recorded.Comet assay showed a concentration dependent increase in deoxyribonucleic acid(DNA) strand breaks in Fe_2O_3-NPs treated groups.Cell cycle analysis revealed 88.4% of cells in sub-G1 apoptotic phase,suggesting cell death in Fe_2O_3-NPs(2.0 mg/m L) treated group.Taking together,the genotoxicity induced by Fe_2O_3-NPs highlights the importance of environmental risk associated with improper disposal of nanoparticles(NPs) and radish can serve as a good indicator for measuring the phytotoxicity of NPs grown in NP-polluted environment.
文摘Kinnow mandarin is a high value citrus crop in the fruit industry.However,the fruits are vulnerable to a variety of phytopathogens and suffer huge quantitative and qualitative losses.Pathogenic filamentous fungi like Penicillium digitatum,Penicillium italicum,and Geotrichum candidum are mainly responsible for postharvest losses.Alternative to synthetic fungicides,the bacteria and yeast-based biocontrol approaches are the most efficient means for controlling postharvest diseases.The antagonistic potential of five biocontrol agents such as Debaryomyces hansenii,Lactobacillus plantarum,Metschnikowia pulcherima,Pichia guilliermondi and Rhodotorula minuta var.minuta was assessed under both in vitro and in vivo conditions against the mycelial growth of postharvest pathogens using dual culture method.The results revealed that R.minuta var.minuta was the most promising antagonist with 71.98%,76.18%and 67.46%mean mycelial growth inhibition of P.digitatum,P.italicum and G.candidum respectively,over untreated potato dextrose agar(PDA)plates after 192 h of incubation under in vitro.Further,under in vivo,the fruits treated with R.minuta var.minuta did not impair the quality and sensory attributes during ambient storage.Hence,R.minuta var.minuta proved an eco-friendly and safer substitute to synthetic fungicides for postharvest disease management of Kinnow mandarin fruits.
基金supported by DBT grant (No. BT/PR8871/PBD/16/1052/2013), Govt of India
文摘Xanthomonas axonopodis pv. punicae (Xap) causing bacterial blight is an important pathogen that incurs significant losses to the exportability of pomegranate. Xap uses the Xop TTSS-effector, via the type three secretion system, to suppress pomegranate immunity. Here, we investigate the role of XopL during blight pathogenesis. We observed that XopL is essential for its in planta growth and full virulence. Leaves inoculated with Xap AxopL produced restricted water-soaked lesions compared to those inoculated with wild-type Xap. XopL supports Xap for its sustained multiplication in pomegranate by suppress- ing the plant cell death (PCD) event. We further demon- strated that XopL suppresses immune responses, such as callose deposition and production of reactive oxygen species (ROS). RT-qPCR analysis revealed that immune responsive genes were upregulated when challenged with Xap AxopL, whereas upregulation of such genes was compromised in the complemented strain containing the xopL gene. The transiently expressed XopL::EYFP fusion protein was local- ized to the plasma membrane, indicating the possible site of its action. Altogether, this study highlights that XopL is an important TTSS-effector of Xap that suppresses plant immune responses, including PCD, presumably to support the multiplication of Xap for a sufficient time-period during blight disease development.