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DIVERSITY ANALYSIS OF Drechslera maydis, THE INCITANT OF MAYDIS LEAF BLIGHT OF MAIZE AND ITS MANAGEMENT
(Punjab Agricultural University, Ludhiana, 2022) Bagaria, Pravin Kumar; Vineet Kumar
The investigation entitled “Diversity analysis of Drechslera maydis, the incitant of maydis leaf blight of maize and its management” was carried out at PAU Ludhiana and ICAR-IIMR, Ludhiana during 2019-2021. The sixty-nine isolates of D. maydis were collected from Punjab and other states showed significant variation in terms of cultural, morphological, and pathological characteristics. The majority of isolates (31) were having greyish black growth of the mycelium on the PDA medium, while 10, 11 and 17 isolates were black, grey and whitish grey, respectively. Most of the isolates (37) showed rough appressed type growth pattern, whereas sectoring and irregular margins were present in 36 isolates. The twenty isolates recorded slow growth (6.0 mm/day). The isolates Dm_8, Dm_46, Dm_58, and Dm_69 showed minimum number septa (3-5 septa/conidium) whereas maximum number of septa (8-12) were observed in isolate Dm_22. Similarly, maximum and minimum spore count (×104/ml) were recorded in isolates, Dm_29 (58) and Dm_51 (11), respectively. Isolate Dm_25 (Ladhowal) recorded minimum incubation (2 days), maximum average lesion numbers (15.03), and highest PDI (94.07%) on susceptible genotype, CM 600, while Dm_26 (Gujarat), the least aggressive isolate, showed maximum incubation period of 4 days with minimum average lesions (11.73) and minimum PDI (61.85%). The isolates were clustered into four groups based on the PDI and representative isolates, viz., Dm_25, Dm_27, Dm_44, Dm_49, and Dm_61 were selected from these groups which were further tested on 10 maize genotypes. The isolate Dm_25 showed maximum average PDI (63.9%), number of lesions (11.1) and AUDPC (846.6), while Dm_27 exhibited minimum average PDI (50.7%), number of lesions (9.1) and AUDPC (668.8). Forty-eight unique polymorphic SSRs were obtained through in-silico analysis of D. maydis strains and filtered to 15 SSRs for further amplification and validation. Six markers (SSR1, SSR4, SSR5, SSR10, SSR13, and SSR15) exhibited high polymorphism with PIC values ranging from 0.81-0.92. Among the 69 isolates, maximum melanin production at 25ºC was recorded in the isolate Dm_25 (2.62 μg/g) while minimum production of melanin (0.37 μg/g) was recorded in Dm_62 isolate. The majority of isolates showed maximum melanin production at temperature range of 25-30°C. Out of 234 maize inbred lines screened under artificial epiphytotic conditions, thirteen genotypes (HKI 42050, V-373, IML66-1, HKI 484-5, LM 13, HKI 163, UMI 112, DQL- 2017, DQL- 2030, DQL- 2231, DQL- 2300-1-1, DQL-2294, and DQL-2105) were found resistant to MLB pathogen. The evaluation of SAR chemicals revealed that maximum disease control (36.72%) and highest yield (29.59 q/ha) were recorded in foliar application of BABA at 200 mg/L followed by ASM (28.66% and 28.34 q/ha) and SA (25.73% and 28.06 q/ha) at 200 mg/L, respectively, as compared to the inoculated control (24.62 q/ha). An overall trend of an upsurge in defensive enzymes (PAL, β-1,3 glucanase and chitinase), antioxidative enzymes (POX and PPO), total phenols and flavonoids was found in inoculated plants of Punjab Sweet Corn 1 treated with SAR chemicals up to 6 days after treatment. Thus, these resistant genotypes may serve as an important source in resistance breeding program against maydis leaf blight and SAR chemicals could be applied for disease management in maize.
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Mapping of stripe rust resistance gene(s) in recombinant inbred lines of Triticum aestivum L.
(Punjab Agricultural University, Ludhiana, 2022) Waris, Mohammad; Jaspal Kaur
Stripe rust caused by Puccinia striiformis f.sp. tritici (Pst) has been identified as the most devastating wheat rust disease and is considered one of the major constraints on wheat (Triticum aestivum L.). The pathogen's polycyclic and airborne nature causes the emergence of novel pathotypes, resulting in the breakdown of many resistance genes and considerable losses in grain yield and quality. To combat the emergence of novel pathotypes, breeders and plant pathologists are constantly on the lookout for stable and long-lasting sources of resistance. Thus, this research work was designed to find novel sources of resistance. A 441 germplasm entries were evaluated, first for their seedling response against the most prevalent pathotypes of Puccinia striiformis f.sp. tritici (238S119, 110S119, and 46S119). Based on infection-type data, out of the 441 lines, 30 lines were found highly resistant to all three pathotypes tested, and 27 lines were highly susceptible. The same entries were also tested for adult plant resistance against stripe rust under field conditions at Ludhiana and Gurdaspur during 2019-21. From the field response against stripe rust infection, i.e., based on final rust severity (FRS) and area under disease progress curve (AUDPC) for all three years at Ludhiana and Gurdaspur, the lines were categorized into highly resistant, resistant, moderately resistant, moderately susceptible, and susceptible. To see the performance of genotypes in multi-environments the data was subjected to GGE biplot analysis. Wheat genotypes were inconsistent in terms of stripe rust reaction at the tested locations. IC111939 (G1) was found to be the "ideal" genotype in both environments. Gene postulation in the 45 lines which shows both all-stage resistance as well as adult plant resistance was done by using 13 known YR geneassociated markers pertaining to 5 Yr genes (Yr5, Yr10, Yr15, Yr24, and Yr26). Yr5 presence was detected in sixteen lines with two linked markers, i.e., Xwmc175 and Xgwm120; Yr10 was detected in ten lines linked with the marker Xpsp3000; Yr15 was detected in fourteen lines with two linked markers, i.e., Xgwm413 and Xgwm273; Yr24/26 was detected in 15 lines with two linked markers, namely Xbarc181 and Xbarc187. For mapping of stripe rust resistance genes in RILs of bread whe at, four F5:6 RIL populations (IC530087 x PBW621, IC530078 x PBW621, IC553914 x PBW621, and IC529094 x PBW621) were tested with stripe rust pathotypes at the seedling stage (238S119, 46S119, and 110S119) as well as at the adult plant stage against a mixture of pathotypes. The same amounts of DNA from ten resistant (R) and ten susceptible (S) lines from each of the four populations were used to make the R and S bulks. A BSA-based 90K SNP array was performed, and 81,423 SNPs were reduced to 71,991 KASP SNPs. The polymorphic SNPs were then used for the mapping of stripe rust resistance genes in all the RILs. A total of 66 KASP markers were developed from the sequencing data. Out of 66 KASP markers, 35 were found to be polymorphic between the parents, and 19 were validated on RIL populations. Mapping using these 19 markers led to the identification of five major QTLs, qYr-pau1A_P5, qYr-pau-5B_P5At, qYr-pau-5A-p11, qYr-pau-6A, qYr-pau-2B_P7, and one minor QTL, qYrpau-P9-3b, on chromosomes 1A, 5B, 5A, 6A, 2B, and 3B, respectively. KASP markers associated with these genes can be directly utilized for marker-assisted breeding in wheat.
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Mapping of Karnal Bunt (Tilletia indica Mitra) resistance gene(s) in recombinant inbred lines of bread wheat
(Punjab Agricultural University, Ludhiana, 2022) Bromand, Ferdaws
The current study was conducted to evaluate a set of 972 NBPGR (National Bureau of Plant Genetics and Resources) accessions and three recombinant inbred lines (RILs) derived from Karnal bunt (KB) resistant donors viz., ALDAN, CMH77.308, and H567.71 in the background of susceptible parent WH542 at PAU, Ludhiana during crop seasons from 20192022. Out of the total 972 accessions evaluated for resistance against Tilletia indica; 417 lines were found resistant over the three years. These 417 lines included 302 highly resistant lines with zero percent KB infection and 115 lines having KB infection up to 5.0 percent. The phenotyping of three RIL populations of ALDAN „S‟ IAS 58 x WH 542, 208 lines screened for KB resistance reported 24 lines having complete resistance i.e., 0% KB infection and the rest of the 184 lines exhibited 0.1 to >20 percent infection. In RIL population CMH 77.308 x WH 542, out of 75 lines screened for KB resistance, 15 lines were reported to be completely resistant having 0.00 percent KB infection and the rest 60 lines showed 0.1 to >20 percent infection. Likewise, in the RIL population H567.71/3*PAR x WH542, a total number of 72 lines screened for KB resistance, 12 RILs were reported to be completely resistant i.e., 0% KB infection the rest 60 lines showed 0.1 to >20 percent infection. A further panel of 63 lines from two RIL populations i.e. ALDAN „S‟ IAS 58 x WH542 and H567.71/3*PAR x WH542 were subjected to genotyping using SNP markers. This panel consisted of 55 resistant and 8 highly susceptible lines from the two crosses. As a consequence, the present study has identified three major QTLs: qKB.pau.AW-4A.1, qKB.pau.AW-4A.2, and qKB.pau.AW1A from ALDAN „S‟ IAS 58 x WH542 RIL populations. Similarly, qKB.pau.HW-1A.1, qKB.pau.HW-1B, and qKB.pau.HW-1A.2 are the notable QTLs detected from the H567.71/3*PAR x WH542 RIL populations during 2019–2020 and 2020–21. The QTLs detected across these environments may be considered more stable and robust as well as may be utilized in the further breeding program for KB resistance.
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Etiology and management of pod rot of mungbean [Vigna radiata (L.) Wilczek]
(Punjab Agricultural University, Ludhiana, 2022) Harwinder Singh; Amarjit Singh
Mungbean [Vigna radiata (L.) Wilczek] is one of the most important pulse crops cultivated in three different seasons, viz., kharif, rabi and summer. However, it is prone to large number of fungal, bacterial and viral pathogens which cause various diseases. Pod rot of mungbean [Vigna radiata (L.) Wilczek] has been emerged as serious disease problem in Punjab and adjoining states in the recent years. The disease appears as discoloration of pods simultaneously with other symptoms such as rotting, shrivling, softening and rotting of seeds in mungbean particularly in the Kharif season crop. The occurance of pod rot was observed in varying intensities on different cultivars in different districts of Punjab. Among the seven districts, the maximum disease incidence i.e. 55.59 per cent was found in Ludhiana followed by Gurdaspur (53.91%), Faridkot (52.06%), whereas the minimum disease incidence of 15.76 per cent was found in Moga. The pathogens associated with syndromes of pod rot were identified as Fusarium equiseti and Fusarium chlamydosporum through morphological as well as molecular characterization by using ITS and EF1/EF2 primers. Pathogenicity of the isolated organisms was established through Koch’s Postulates. Temperature ranges of 2535oC and pH range of 5.5-7.5 were found more conducive for the growth of F. equiseti and F. chlamydosporum as well as the pod rot disease development. Sucrose as carbon source whereas Potassium nitrate as nitrogen source was found to be more supportive for the growth of both the pathogens. Among the tested media, four i.e., Potato dextrose gar, Czapek’s dox agar, Richard’s agar, oat agar were found more supportive for the colony growth of both pathogens. Out of the seventy five mutant genotypes of mungbean screened against the pod rot under natural epiphytotic conditions, only ML 2524 showed the Resistant (R) reaction whereas forty one showed moderately resistance (MR), twenty four moderately susceptible (MS) whereas nine showed susceptible (S) reaction to pod rot disease. A combination of Trifloxystrobin + Tebuconazole (75% WG) @ 0.07 per cent followed by tebuconazole 25 EC @ 0.1 per cent were proved to be most effective under in vitro as well as in vivo conditions.
Open Access
Pathological and molecular variation in Puccinia triticina the incitant of leaf/brown rust of wheat and host resistance
(Punjab Agricultural University, Ludhiana, 2021) Harmandeep Kaur; Jaspal Kaur
Leaf/brown rust of wheat, caused by Puccinia triticina (Pt), is one of the most important diseases of wheat worldwide. To study the virulence pattern/ diversity of P. triticina, the surveys for leaf rust occurrence were conducted in Punjab during 2018-2021. SBS Nagar (Saroya block) Ludhiana west, Rupnagar (Anandpur sahib) and Gurdaspur were observed as hot spot areas for leaf rust of wheat and disease severity recorded was in the range of 5-40S at different locations. From virulence profiling of the leaf rust infected samples collected from Punjab, it was found that Pt pathotypes 77-5, 77-9, 77-13 (121R60-1,7 ) and 1R 31 are known to occur in Punjab with varied frequencies. Out of which the prevalence of pathotype 77-9 was maximum (62.85%) followed by 121R60-1,7(31.42%). The genetic diversity among Pt isolates was studied using SSR markers which demonstrated that the new pathotype (121R60-1, 7) is more closely related to the pathotype77-9. To know the effectiveness of Lr genes, the leaf rust differentials (Indian and in Thatcher background) and commercial wheat cultivars/ known Lr gene lines were scored against P. triticina infection at four different locations of Punjab (Ludhiana, Gurdaspur, SBS Nagar & Abohar). The lines carrying Lr genes; Lr 9, Lr 19, Lr 24, Lr 25, Lr 28, Lr 29, Lr 32, Lr 42, Lr 45, Lr 47, Lr 52, Lr 57, Lr 58, Lr 76 exhibited resistance against the most prevalent pathotypes (77-5, 77-9 and 121R60-1, 7) of P. triticina in Punjab. One hundread and ninty seven wheat germplasm lines were evaluated at the seedling stage as well as at the adult plant stage against these pathotypes. Based on the seedling reaction test and adult plant response at Ludhiana and Gurdaspur during 2018-2021, it was inferred that thirty six lines showed highly resistant reaction whereas twenty six lines were highly susceptible with AUDPC value >400 and FRS value >40S. DNA of all these test lines was amplified with Lr gene specific markers to identify the gene(s) present in these lines. Based on the molecular data and race specific infection response at seedling as well as at adult plant stage; the leaf rust resistance genes Lr 9, Lr19, Lr24, Lr25, Lr 28, Lr29, Lr32, Lr42, Lr45, Lr47, Lr52, Lr57, Lr58 and Lr76 were postulated in these lines. All stage resistance was imparted by the genes; Lr9, Lr19, Lr24 and Lr28 against prevalent Pt pathotypes in Punjab. The F3 and F5 generation of seven populations were evaluated against P. triticina from 2018-2021 under field conditions at PAU (Ludhiana). The genotypic ratio 1:2:1 and 1:1 for F3 and F5 population respectively fit significantly on the phenotypic data. For gene mapping the resistant and susceptible bulks along with resistant and susceptible parents were genotyped with 90K SNP chip Ilumina array. The SNPs located on the chromosome 5A for population (IC 321853 X HD 3086); 7B for population (IC 549520 X HD 3086); 1B,1D and 6A for population (IC 252609 X HD 3086); 1A, 1D, 3B, 4B and 5A for population (IC 252742 X HD 3086) and 1A, 1B, 2B, 3B and 7A for population (IC 539316 X HD 3086) were selected for designing the KASP markers.
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Biology of Ustilaginoidea virens (Cooke.) Takahashi and mapping QTL for resistance to false smut in rice (Oryza sativa L.)
(Punjab Agricultural University, Ludhiana, 2021) Kamboj, Ishwinder; Lore, Jagjeet Singh
The false smut of rice is caused by fungus Ustilaginoidea virens (Villosciclava virens). The disease causes 0.2-49% yield losses besides qualitative losses. The knowledge of disease cycle about the pathogen and the availability of resistant sources for false smut is lacking. The present study was conducted with various treatments for seed-borne, soil-borne and air-borne nature of primary inoculum in pot experiment. The disease incidence and percent infected panicles was more in case of plants with uncovered panicles (10-36%) than covered panicles (0-9%), in infected soil (9-33%) than in sterilized soil (8-13%) and in case of plants raised from infected seed (0-10%) than from healthy seed (0%). The percent infection was the highest in case of air-borne experiment in plants with uncovered panicles than in plants grown in infected soil whereas the plants raised from infected seeds reported only 5% infection. In another experiment, screening of 212 rice accessions against false smut disease under field conditions resulted in selection of 27 resistant lines. These lines were further screened under artificial conditions against the disease along with susceptible checks (GSR123 and PR116) resulted in selection of 19 resistant lines. Out of 19, the lines CANAROXA and IAC 47 with good agronomic trait were used as donors for preparing crosses with PR126 and PR116, respectively. Out of 78 SSR markers, the markers which show polymorphism in PR116  IAC 47 includes RM16493, RM18457, RM25149 and RM28404 on chromosome 4, 5, 10 and 12, respectively. On the other hand, the polymorphic markers in case of PR126  CANAROXA includes RM104, RM289, RM7434, RM8243, RM264, RM25149, RM10 and RM26643 on chromosome 1, 5, 6, 8, 10 and 11, respectively. These polymorphic markers were used to identify genetic diversity in the mapping population. However, the identified polymorphic markers in this study fail to depict the association between the marker and false smut resistance gene due to lack of definite pattern of markers at loci. Further analysis in next generation will help us to uncover the association between the marker and the false smut resistance gene.
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Potential of indigenous strains of Bacillus spp. against black scurf and common scab of potato
(Punjab Agricultural University, Ludhiana, 2022) Gurveer Singh; Buttar, Daljeet Singh
Black scurf and common scab are the two major diseases which are affecting the potato crop throughout the Punjab. 22 isolates of Rhizoctonia solani, 9 isolates of Streptomyces scabies and 26 isolates of Bacillus spp. were isolated, purified and identified on the basis of morphological and biochemical characteristics from highly infected potato tubers and rhizospheric soil samples. Under the dual culture assay the maximum per cent mycelial growth inhibition was shown by B4 isolate (56.67 per cent) of Bacillus spp. Under the antifungal volatile production assay, the maximum mycelial growth inhibition of 75.00 per cent was shown by B4 isolate of Bacillus spp. which was statistically at par with B7 (73.52 %). In the culture filtrate assay, at 50 per cent concentration B4 isolate showed maximum mycelial inhibition of 75.19 per cent. Under the dual culture assay and the maximum zone of inhibition (45.33 mm) was shown by B4 which was at par with that of B7 (44.23 mm) against S. scabies S4. During quantitative analysis of chitinase production, the maximum production was found in B7 isolate (8.19 unit/ml) followed by B4 isolate (8.02 unit/ ml). Under siderophore production assay, the isolate B4 showed maximum production of siderophores (9.22unit/ml) which was statistically at par with that of B7 (9.19 unit/ml). The B7 isolate exhibited maximum β-1,3-glucanase production (4.09 unit/ml) which was followed by that of B4 (4.06 unit/ml). Molecular identification of R. solani R2, S. scabies S4 and Bacillus spp. was done and accessions were obtained. B. subtilis B2, B. subtilis B4 and B. amyloliquefaciens B7 were selected for their evaluation under the pot house and field conditions. During the two consecutive years (2019 and 2020) the Tuber Dip 15g + Soil 3.5kg (B4) treatment gave highest tuber sprouting (97.78 and 94.44%). Under the field evaluation the chemical (Emesto Prime) treatment (5.33%) was at par with Tuber Dip 15g + Soil 2.5kg (B4) and Tuber Dip 15g + Soil 3.5kg (B 4) with black scurf severity of 8.00 and 6.67 per cent. The common scab severity under chemical (3% boric acid) was 5.56 which was numerically less than other treatments but was at par with the Tuber Dip 10g + Soil 3.5kg (B 4) and Tuber Dip 10g + Soil 3.5kg (B 7) treatments which exhibited disease severity of 12.22 and 16.67 per cent. Tuber Dip 15g + Soil 3.5kg (B 4) also leads to high plant growth (71.47 and 59.31 cm during 2019 and 2020) and yield (154.29 and 147.77 qt/acre during 2019 and 2020) of potato. Under field conditions the Tuber Dip 15g + Soil 3.5kg with B. subtilis B4 had showed maximum cfu/g of 6.4 × 109 and 7.3 × 109 during 2019 and 2020, respectively at 0 days which was effective upto 45 days of crop growth period. B. subtilis B4 had maximum spore count at zero day (8.3 × 1010). The temperature of 4°C and 0°C were found to be most effective one for storage of talc based bioformulation in polythene bags for more than nine months. Based on the findings B. subtilis B4 acts as most potent strain of Bacillus spp. against both the diseases.
Open Access
Molecular and biochemical bases for resistance to Alternaria blight in Indian mustard
(Punjab Agricultural University, Ludhiana, 2022) Bharmera, Pooja; Sandhu, P.S.
Alternaria blight of oilseed brassicas caused by Alternaria brassicae is of great economic significance and considered the most destructive and widespread disease of all continents. The survey was conducted for Alternaria blight in Indian mustard during the 2019-20 and 2020-21 crop seasons to study its prevalence and to collect isolates from different geographical regions of Punjab and other mustard growing areas of India. The disease was found to be prevalent in low to moderate form with average disease severity of 26.97 and 22.16% in Punjab and 27.96 and 26.00% in other regions of India during both years. The 49 isolates collected from the survey were observed to be significantly variable in terms of cultural, morphological, and pathological characteristics. On the basis of these characteristics, Ab31- PAU, Ludhiana isolate was found the most virulent pathotype, and Ab04-Daun Kalan, Patiala was the least virulent isolate. The effective inoculation method against Alternaria blight under laboratory experiment (both in detached true and cotyledonary leaf assay) was spore suspension drop + agarose gel however, in pot experiment under polyhouse condition, the foliar spray was found the most efficient method for the screening of germplasm. Further, 261 germplasm lines of Indian mustard were screened against the local isolate Ab31-PAU, Ludhiana of Alternaria brassicae by foliar spray inoculation method. The average disease severity was 47.31% (24.85-72.13%), 44.70% (21.8967.42%), and 46.06% (23.37-69.77%) for 2019-20, 2020-21, and pooled years, respectively. Four genotypes viz., IM-152, ZEM-3356, IM-87, and J-8 outperformed among the germplasm lines against the pathogen. Associative transcriptomics study was done for Alternaria blight resistance, three genes related to Alternaria blight infection (TSD2, FAD3, and AT1G45231), six genes for plant innate immunity having NLR domain (F24L7_13, NPH4, ILL2, TIR1, FUS6, and CDC48), and two genes related to the phenylpropanoid pathway (ABCB2 and F7A10.28) were identified. Accordingly, these putative genes showed the importance in defense pathway mechanisms. Eighteen genotypes that showed moderate resistant response were found to be promising w.r.t. different biochemical parameters studied. An overall trend of an upsurge in plant secondary metabolites (glucosinolates and total phenols) and defensive enzymes (peroxidase, superoxide dismutase, and phenylalanine ammonia-lyase) was detected after inoculation in diverse genotypes together with the susceptible check (Rohini). A significant negative correlation was observed between all biochemical components and percent disease severity. The correlation was the maximum for PAL enzyme activity with percent disease severity. Thus, these resistant genotypes may serve as an important source of resistance in breeding for Alternaria blight resistance in oilseed Brassica.
Open Access
POTENTIAL OF NATIVE STRAINS OF BIOAGENTS FOR THE MANAGEMENT OF DAMPING OFF IN ONION AND TOMATO
(Punjab Agricultural University, Ludhiana, 2020) Suma, Moka; Narinder Singh
Damping off is a destructive disease in onion and tomato caused by Fusarium oxysporum f.sp.cepae and Rhizoctonia solani in nursery growing areas of Punjab. Rhizospheric soil samples were collected from onion and tomato growing nurseries of Sangrur, Ludhiana and Amritsar districts of Punjab and analysed for antagonistic microflora. Seventeen isolates of Trichoderma and fifteen isolates of Pseudomonas were isolated and screened in vitro against the Fusarium oxysporum f.sp.cepae and Rhizoctonia solani causing damping off in onion and tomato respectively through dual culture technique, volatile and non-volatile compounds. Among all tested isolates Trichoderma isolate (T8) has shown maximum inhibition of Fusarium oxysporum f.sp.cepae (71.42%) and Rhizoctonia solani (84.22%) by dual culture. This isolate also showed maximum inhibition to Fusarium oxysporum f.sp. cepae and Rhizoctonia solani by volatile and non volatile metabolites of Trichoderma isolates. Pseudomonas isolate Pf10 has showed maximum mycelial inhibition of Fusarium oxysporum f.sp.cepae (64.37%) and Rhizoctonia solani (65.93%) by dual culture. It also showed mycelial inhibition of Fusarium oxysporum f.sp.cepae and Rhizoctonia solani by volatile and non volatile compounds released from Pseudomonas isolates. Biochemical tests for estimation of cell wall degrading enzymes has shown the ability of the Trichoderma isolate (T8) and Pseudomonas isolate (Pf10) to produce high level of chitinase (17.57 and 14.20 unit/ml respectively) and β-1,3-glucanase (1.42 and 1.52 unit/ml respectively). Pf10 also showed highest siderophore production of 33.67mm. The efficacy of talc based bioformulations of Trichoderma (T8) and Pseudomonas isolate (Pf10) when applied alone as well as in combination under pot and field conditions was checked against damping off of onion and tomato. In onion under field conditions, Pseudomonas (Pf10) and Trichoderma (T8) when applied as seed+soil treatment @15g/kg showed maximum inhibition of disease (89.99 and 88.75 percent respectively). They also acted as plant growth promoters with root length (14.64 and 14.17 cm), shoot length (25.33 and 25.00cm), fresh weight (4.51 and 4.45g), dry weight (1.82 and 1.80g) and finally yield (195.76 and 193.94 q/acre) of the crop. In tomato under field conditions Pf10 and T8 when applied as seed+soil treatment@15g showed maximum inhibition of damping off disease (88.89 and 85.71 per cent) with yield of 221.86 and 221.40 q/acre respectively. Pf10 and T8 (seed+soil treatments@15g) also acted as plant growth promoters with pooled root length (23.67 and 22.50 cm), shoot length (34.49 and 33.79cm), fresh weight (4.53 and 4.49g) and dry weight (2.22 and 2.19g) respectively during 2018 and 2019. Rhisosphere soil sampling from treated onion and tomato nursery up to 45 days showed decrease in antagonistic population up to 15 days and then it started increasing. The selected antagonists showed promising rhizospheric competency throughout the growing season that was enough to control damping off disease of onion and tomato in both pot and field conditions. Molecular identification of the Trichoderma T8 using endochitinase ech42 gene specific primers was done and found that it is closely related to Trichoderma asperellum and Pseudomonas isolate Pf10 using universal primer and sequence analysis showed similarity with Pseudomonas fluorescens. Study of shelf life of the talc based bioformulation revealed that antagonist Trichoderma asperellum (T8) and P. fluorescens (Pf10) can remain potent for 6 months when stored at room temperature while at low temperature storage (4° and 0°C) they can remain potent upto one year. For Mass multiplication sugarcane press mud, rice leaves and wheat bran supported rapid, maximum growth and sporulation of Trichoderma asperellum T8 at 25°C

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