Characterization of bread wheat germplasm for spot blotch resistance and its association with yield and yield related traits

Abstract

Spot blotch (Bipolaris sorokinana Sacc. In Borok. Shoem) is an important foliar
disease of wheat in South-East Asia. This is a destructive disease of wheat
in warm and humid wheat growing regions of the world. In India spot
blotch (B sorokinana ) is reported to be important leaf blight disease. Two
hundred accessions obtained from CIMMYT were evaluated against spot
blotch severity under epiphytotic conditions during 2014-2015 and 2015-
2016 at G.B. Pant University of Agriculture and Technology, Pantnagar
to identify resistant genotypes against spot blotch. The accessions were
evaluated in augmented block design (ABD) and data were recorded for
six characters viz., disease severity, days to 75% heading, days to maturity,
plant height, thousand grain weight and grain yield. The statistical analysis
revealed that variance was found highest for area under disease progress
curve AUDPC followed by grain yield and lowest for days to maturity.
Spot blotch severity has significant and negative correlation with grain
yield, thousand grain weight, plant height, days to 75% heading and days to
maturity. Simultaneously, AUDPC has shown negative correlation with all
the characters. Out of 200 accessions, 78 were found resistant to spot blotch
over 2 years and four accessions were found highly resistant on the basis of
area under disease progress curve (AUDPC) in both the years which could
be used as donors for the development of spot blotch resistant varieties of
wheat. The development of disease resistant cultivars is considered as the
most effective control strategy for spot blotch.