Components of partial resistance against Neck Blast (Pyricularia Oryzae) in basmati rice
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
The neck blast disease caused by Pyricularia oryzae was highly prevalent throughout the Punjab state with disease incidence ranging from 5.6 to 52.4 per cent on various basmati varieties. Highest disease incidence was observed in Mahal Kalan village of Barnala district. Amongst varieties, Pusa Basmati 1121 had highest value of disease incidence followed by Pusa Basmati 1401, Pusa Basmati 1509 and CSR 30. Significant variability amongst the neck blast isolates of the pathogen was observed with respect to various morphological and cultural characters viz., colony colour, colony texture, colony margin, mean radial growth (mm), spore size and sporulation intensity. The average sporulation intensity of the isolates on Oatmeal agar medium was 7.55×106 conidia /ml which was higher than the average sporulation intensity of isolates on Paspalum grass medium i.e. 6.97×106 conidia /ml. Three isolates namely NB 55, NB 57 and NB 60 were categorized as fast growing isolates with radial growth of >8mm per day. Various architectural features viz., flag leaf angle, flag leaf length, flag leaf width, panicle axis, panicle diameter, degree of exertion of panicle, culm length, 50% flowering and node aging were recorded in order to find correlation with various disease parameters viz., lesion length, panicle blast severity, area under disease progress curve (AUDPC), incubation period, disease incidence (%) and apparent rate of infection (R). Overall, flag leaf angle, panicle axis and node ageing emerged out to be three important components of partial resistance. Forty five basmati rice genotypes were screened under both artificial and natural conditions against the disease. Four genotypes i.e. Tetep, INGR 15001, INGR 15002 and Pusa Basmati 1637 were found to be moderately resistant to most virulent isolate NB 7 with susceptibility index was below 3 and they could be used as donors in breeding for disease resistance.
Description
Keywords
null
Citation
Sohal, Manarshroop Kaur (2020). Components of partial resistance against Neck Blast (Pyricularia Oryzae) in basmati rice (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.