The NIL Pusa1718-14-2-150 was the best performer in first
mega environment (Fig. 2). A comparison plot based on “ideal
genotype” revealed Pusa1718-14-2-150 as the best performer as
well stable across locations as compared to its recurrent parent
PB1121. Based on the position of PB6, it can be deduced that
the PB6-NILs Pusa1728-23-33-31-56 and Pusa1884-9-12-14 were
comparatively superior performing and stable across environments
(Supplementary Fig. S3).
3.6. Screening of the NILs for blast resistance
Screening of blast gene introgressed NILs under artificial epiphytotics
using a total of 35 M. oryzae isolates revealed that NILs and
the donor parent carrying blast resistance gene Pi2 were resistant
against 32 isolates and susceptible for 3 isolates namely, Mo-ni-
15, Mo-ni-67 and Mo-ei-bara1, depicting a resistance spectrum of
91.0% (Fig. 3; Supplementary Table S2). However, the NILs carrying
Pi54 were resistant only against ten isolates, but susceptible
against 25 isolates, depicting a resistance spectrum of 29%. Interestingly,
Pi54 was found to impart resistance against all three
isolates that compromised Pi2 gene. Further, during two consecutive
years of field screening for blast resistance, the monogenic-NILs
carrying Pi2 were found highly resistant at both the locations UBNMalan
and UBN-Hazaribagh, while, the NILs carrying Pi54 were
highly susceptible at UBN-Malan and moderately resistant at UBNHazaribagh.
The pyramided lines carrying Pi2 + Pi54 in the background of
PB1121 and PB6 exhibited resistance against all 35 isolates, showing
a 100% resistance spectrum. Further, these pyramids were
found to be highly resistant to blast disease at UBN-Malan, UBN