- Maize genotypes received under AICRP (Maize) were screened against turcicum leaf blight of maize. Trap nursery trials were conducted for naturally occurring diseases on maize genotypes.
- Samples have been collected and new reports of diseases have been published.
- Samples were collected from Meghalaya, Assam, Arunachal Pradesh, Sikkim and Tripura. Phytophthora was identified based on morphological keys and confirmed using PCR based molecular tools with ITS1/ITS2 and A2/I2 primers
- Trichoderma were isolated and based on ITS region sequencing, the 7 species of Trichoderma could be identified as T. asperellum, T. brevicompactum, T. harzianum, T. koningiopsi, T. virens and T. viride. Among them,6 Trichoderma spp. were tested for bio-efficacy against P. citrophthora using dual culture technique, effect of volatile compounds and non-volatile compounds. In dual culture, T. harzianum was found effective, whereas in volatile compounds experiment, T. brevicompactum was superior over other species.In non-volatile effect experiment, T. brevicompactum followed by T. harzianum were found superior.
- Two different formulations of Trichoderma viz. sorghum grain based and jaggery based have been produced and being evaluated on Phytophthora inoculated citrus seedlings.
- The pathogen (Ralstonia solanacearum) causing wilt disease of solanaceous crops and ginger was isolated and identified using specific 16SRNA OLI1/Y2 and 759/760 primers. Isolates were subjected to biovar grouping and grouped under Biovar-3, which indicated that Ralstonia isolates from NEH states fall under Biovar-3 category. The sequevar analysis of Ralstonia is being carried out with universally accepted “Multi-locus sequence typing” (MLST) scheme using house-keeping genes. We have characterized representative isolates using fliC (Flagellin protein encoding gene C), gapA (Glyceraldehyde 3-Phosphate dehydrogenase Oxireductase), hrpB (Regulatory Transcription regulator), gdhA (glutamate dehydrogenase oxidoreductase) genes. The sequences have been processed and submitted to NCBI gene bank.
- Bacillus subtilis and Pseudomonas fluorescens were isolated from soil and tested against Ralstonia solanacearum. Both P. fluorescens and Bacillus subtilis were found producing clear zone of inhibition against R. solanacearum.
- Thirteen genotypes of tomato were screened against bacterial wilt (Ralstonia solanacearum) under inoculated sick plot conditions. The variety ‘Pusa ruby’ recorded maximum disease incidence and lowest yield, whereas the minimum disease with maximum yield was recorded with Meghalaya Tomato-1.
- Under management trials against bacterial wilt (R. solanacearum) of solanaceous crops and ginger, the lowest per cent infection was recorded in ATW (1:3:5) treated plots.
- The pathogen (Pythium myriotylum) was isolated from soft rot of ginger. Maximum infection was noted from pre-infected rhizomes. Under management trials, the lowest per cent infection, highest yield and minimum yield loss was recorded in the plot treated with Poultry Manure (2.5t/h) + Mulching (Ambrosia spp.) + Ridomil MZ-72 @ 2g/l.
- The pathogen (Phytophthora palmivora) from bud rot of arecanut was isolated. Under management trials in protected conditions, the minimum PDI was obtained from seedlings applied with Aliette 80 WP @ 2.5g/l of water followed by Ridomil MZ-72 @ 2.5g/l of water. The bio-agents T. viride (phylloplane) followed by T. viride (soil) and T. harzianum attained minimum PDI among bio-agents.
- Symptomatological identification and PCR detectionof Papaya ring spot virus, Banana bunchy top virus from Meghalaya was done.
- Symptom identical to vein banding was identified in king chilli (Capsicum chinense), bird eye chilli (Capsicum frutesense).The PCR assay confirmed the presence of poty-virus infection in symptomatic king chilli plants. Further, confirmation at species level is being done.
- Disease screening of 125 local maize germplasms of North East India and seven maize varieties; RCM 1-3, Hemant, RCM-76, RCM-75, DS 61, Vijay Composite and Local Yellow has been done against Turcicum leaf blight (TLB) and Banded leaf and sheath blight (BLSB). None of the local germplasms or varieties showed resistance to the Turcicum leaf blight, while RCM-76 showed minimum severity among all maize germplasms/varieties tested.
- The symptomatic leaves, affected by BLSB, were collected from the field and the causal fungus Rhizoctonia solani was isolated in laboratory for further screening.
- Characterization of Elsinoe spp. causing scab disease of citrus and its management through native bio-control agents in NEH Region was carried out.
- New species of mushroom have been collected and deposited. The technology for mushroom cultivation was standardized. Training to the farmers was imparted.
Continuation of previous work
- Continuation of variability studies of Phytophthora among NE states
- Submission of various gene sequences of R. solanacearum, those has been already processed to PAMDB/NCBI/EMBL
- Repetition of field trial against bacterial wilt and preparation of commercial formulations.
- Repetition of field screening of maize germplasms/varieties against TLB and BLSB.
- Repetition of field screening of rice germplasms/varieties against blast and sheath blight.
- Molecular detection and characterization of virus associated with solanaceous vegetables particularly in tomato and chilli.
- Continuation of research on mushroom cultivation technology.