Pathotyping of Pyricularia oryzae causing neck blast of basmati rice in Punjab
| dc.contributor.advisor | Jain, Jyoti | |
| dc.contributor.author | Jasvir Singh | |
| dc.date.accessioned | 2018-05-25T13:49:38Z | |
| dc.date.available | 2018-05-25T13:49:38Z | |
| dc.date.issued | 2018 | |
| dc.description.abstract | The neck blast disease was prevalent throughout the Punjab state with disease intensity ranging from 5 to 65 per cent on different basmati varieties. The highest disease incidence was observed in south western districts of the state on variety Pusa basmati 1401 followed by the Pusa basmati 1121, Pusa basmati 1509, CSR 30 and PB 3 respectively. The neck blast isolates of Pyricularia oryzae were significantly variable from each other with respect to colony colour, colony texture, colony form, colony margin, mean radial growth (mm), spore size and sporulation intensity. Eighteen isolates were designated as medium growers with Kr value of 6-8mm/24 hours and only three isolates (NB-1, NB-4 and NB-33) as fast growers having Kr > 8mm/24 hours. All the isolates cultured on oatmeal agar medium (OMA) produced higher conidia per ml (7.49×106) than on paspalum grass medium (6.74×106). Seventeen isolates were pathotypically characterized based on different components of aggressiveness viz. area under disease progress curve (AUDPC), lesion length, incubation period (IP 50), disease incidence (%) and sporulation intensity using near isogenic lines (NILs). Hierarchical cluster analysis of these aggressiveness components categorized the isolates into three distinct groups. Isolate NB-7 was found to be the most virulent followed by NB-51whereas isolate NB-6 was the least virulent. None of the single blast resistance gene was effective against different isolates of neck blast. Out of 69 genotypes evaluated, none was found to be resistant against neck blast disease. Only 4 entries viz. Tetep, Pusa basmati 1637, INGR 15001 and INGR 15002 showed moderately resistant reaction to most virulent isolate NB-7 and can be used as donors in neck blast resistance breeding programme. This is the first systematic study on pathotyping of neck blast isolates in Punjab suggesting the occurrence of three distinct pathotypes in the state. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810047666 | |
| dc.keywords | Neck blast, Pyricularia oryzae, Pathotyping, AUDPC, Lesion length, Disease incidence, Sporulation intensity | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 94 | en_US |
| dc.publisher | Punjab Agricultural University, Ludhiana | en_US |
| dc.research.problem | Pathotyping of Pyricularia oryzae causing neck blast of basmati rice in Punjab | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.subject | null | en_US |
| dc.theme | Pathotyping of Pyricularia oryzae causing neck blast of basmati rice in Punjab | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Pathotyping of Pyricularia oryzae causing neck blast of basmati rice in Punjab | en_US |
| dc.type | Thesis | en_US |