Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Cultural and Pathogenic Variations in Isolate of Rhizoctonia Species from Plants and Soils of Potato Fields in Bangladesh.

M. M. Khandaker
Jagannath university, Dhaka.

M. K. A. Bhuiyan
Bangladesh Sheikh Mujibur Rahman Agricultural University, Salna, Gazupur.

M. A. H. B. Bhuiyan
Bangladesh Sheikh Mujibur Rahman Agricultural University, Salna, Gazupur.

A. Khair
Jagannath university, Dhaka.

Abstract/ Executive Summary:

The study was conducted to determine the cultural, morphological and pathogenic variability in the isolates of Rhizoctonia spp. causing stem canker and bloch scarf of potato. A wide variation was observed in cultural and pathogenic characteristics among the 60 isolates Rhizoctonia spp and Rhizoctonia solani, isolated from, stem, tubers plants and soli of potato. The linear mycelial growth varied form 15.67 to 28.88 mm per 24 hr. the highest mycelia growth rate was founded in isolate BTB 115 followed by DK 64. The lowest growth rate was recorded in P158 isolate. The colony structures were compact, fluffy and slightly fluffy in 45, 10 and 5 isolate. Concentric zones on mycelia colony appeared in 24 isolates, while colonies of 36 isolates were free from zonation. Sclerotic formed singly or in crust and were distributed throughout the plate, either in concentric zones or as cluster at the centre of the plate. Among 60 isolates 14 were binucleate isolates of Rhizoctonia spp. the rest 46 were multinucleate isolates of R solani. Pathogenicity test of all the multinucleate and binucleate Rhizoctonia spp. isolates were carried out on potato.binuclate isolate of Rhizoctonia spp were found almost avirulent on potato. Among 60 isolates, 12 did not infect potato plants, 8 showed symptoms of only stem canker and 2 isolates caused black scurf symptoms. Other 38 isolates showed symptoms of the both stem canker and black scurf. Based on incidence and severity of stem canker and black scurf 38 isolates were classified into five group. Group I, II, III and IV contained 20, 11, 4, 2 isolates. Only one isolate was placed in Group V. the isolates DK 64 and BTB115 were recorded as most virulent causing the highest disease severity on stems of potato plants.

Keywords: Potato, Disease, Pathogenic of potato, Vegetables.

Location: BSMRAU, Salna, Gazipur.

Start Date: 01-07-2005

End Date: 30-06-2006

Program Area: Pest Management

Commodity: Potato

Objectives:

To determine the cultural, morphological and pathogenic variability in the isolated of Rhizoctonia spp. causing stem canker and black scurf of potato in Bangladesh.

Methodology:

A total of 60 isolates of R solani were isolates infected stems, tubers and soils of potato. Pure culture of the isolates were prepared and multiplied on PDA in Petri dishes. Mycelial agar blocks were cut from the growing edge of three days old PDA culture of each isolate using a flame sterilized 5 mm cork borer and transferred to the centre of 90 mm diameter Petri dishes containing solidified PDA. The inoculated plates were incubated for 20 days at 25±1⁰c. Three replicated plants were used for each isolate.

The nuclear status of all isolate of R. solani and Rhizoctonia spp were observed by staining with safranin O solution according to the procedure as described by Bandoni. The safranin O solution was prepared by mixing 6 ml of .75% (w/v) safranin in 50% (v/v) ethanol, 10 ml of 3% (w/v) KOH, 5 ml of glycerol and 79 of distilled water.

Pathogen city test of all the isolates of Rhizoctonia spp was conducted in the experiment plot of BSMRAU, Salna, Gazipur during the crop season 2005-06. A soil experiment plot was inoculated with wheat grains colonized with the isolates of the pathogen. Wheat grains without colonization with any isolates were mixed with soil of the control plots. After 10 days of inoculation potato seeds were sown. Individual unit size was .6 m x 1.0 m. in each unit plot, 10 seed potato tubers were planted in two row. Data on total number of plants and tubers, number of infected plants and tuber were recorded. The severity of stem canker as well as black scurf was recorded following an indexing scale of 0-5, where 0 = no disease symptom, to 5 = plant completely girdled the stem.

PDI = Summation of all ratings/ Number of plants observed x Maximum rating X 100

The experiment was laid out in RCBD with 3 replications for each isolate. Data recorded on various parameters were analyzed using MSTAT-C programme.

Source of Information: Bangladesh Journal od Agriculture, vol. 36(1)2011,(pa no.71-79) ISSN 0253-5408, 87Bangladesh Agricultural Research Council

Article Link (Online Journal):

Funding Source:

1. Government

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Among 60 isolates 14 were binucleate isolates of Rhizoctonia spp. the rest 46 were multinucleate isolates of R solani. Pathogenicity test of all the multinucleate and binucleate Rhizoctonia spp. isolates were carried out on potato.binuclate isolate of Rhizoctonia spp were found almost avirulent on potato. Among 60 isolates, 12 did not infect potato plants, 8 showed symptoms of only stem canker and 2 isolates caused black scurf symptoms. Other 38 isolates showed symptoms of the both stem canker and black scurf. Based on incidence and severity of stem canker and black scurf 38 isolates were classified into five group. Group I, II, III and IV contained 20, 11, 4, 2 isolates. Only one isolate was placed in Group V. the isolates DK 64 and BTB115 were recorded as most virulent causing the highest disease severity on stems of potato plants.

Knowledge Management: Journal