Summary: | Rice sheath rot has become a highly destructive rice disease with a high variability in yield loss levels varying from 20 to
85%. It is caused by many pathogenic agents varying depending on the area, grown varieties, prevailing environmental
conditions, the farming system, other pests, etc. Therefore, sheath rot disease can be effectively managed through crop
improvement strategies viz., discovery of resistance sources from varieties, germplasm, landraces, wild genetic resources and
further deploying them in breeding programmes. In this study, the level of resistance to sheath rot in 43 rice germplasm
accessions were screened and the results were grouped using Darwin 6.0 statistical package from dissimilarity analysis. The
percent disease index (PDI) was calculated and varietal reactions were presented. Out of 43 lines screened against sheath rot,
six entries viz., Gowri, NLR 3449, Navara, Soorakkuruvai, Keralakandasala, krishnahemavathi were categorised as
moderately resistant. Most of the lines and varieties viz., JGL 348, Abhya, LFR293, MDU5, Kalinga, Annada, Kodaikannan,
TP-100008, TP-10106, Kuruvaikalanjium, Kalyani, Maranella, Seeragasamba, Thondi, Kavara, TPS-4, TPS-5, TP 08053
were found as moderately susceptible. However, the germplasm lines Swarna, Kattanur, Dhalaheera and JGL 3855 have
been reported to be resistant to sheath rot. Sixteen germplasm lines viz., Bharathi, Uma, CO 39, Neikuruvai, CO 50,
Rajalakshmi, Karsamba, JGL 1798, CO 51, BPT 5204, Virendra, JGL 1798, CO 51, BPT 5204 and Aman were designated
as susceptible and three germplasm lines viz., Athira, Malampunchan, Adukan were found as highly susceptible. None of the
entry in the present study was recorded as immune. The present investigation revealed that the resistant and moderately
resistant genotypes viz., Swarna, Kattanur, Dhalaheera, JGL 3855, Gowri, NLR3449, Navara, Soorakuruvai,
Keralakandasala, and Krishnahemavathi can be utilised in resistant breeding programmes for the development of sheath rot
resistant lines in rice.
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