National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
Spot blotch caused by Bipolaris sorokiniana is quite important disease and regular breeding programme is in place using resistant donors in different wheat and triticale breeding stations in India. Keeping in view of this, the pre-coordinated yield trial entries are also screened against this disease besides rusts at hot spot locations under artificially inoculated and disease epiphytotic conditions. Pre-coordinated yield trial entries of bread and durum wheats as well as triticales contributed by different wheat breeding centres; Hisar, Ludhiana, Gurdaspur, Pantnagar, Karnal, Jammu, Meerut, New Delhi, Durgapura, Sriganganagar, Malan, Almora, Shimla, Sagar, Powarkheda, Bhavnagar, Bilaspur, Kota, Gwalior, Indore, Vijapur, Jabalpur, Ranchi, Pusa (Bihar), Patna, Faizabad, Sabour, Varanasi, Dharwad, Pune, Niphad, Akola, Parbhani and Wellington, situated in six agroclimatic zones were screened. The evaluation was done from 2005–06, 2006–07 and 2007–08 crop seasons by taking 1490, 1520 and 1510 numbers of entries, respectively. The testing centres for spot blotch were, Faizabad, IARI Pusa (Bihar), Varanasi, Kalyani, Ranchi and Coochbehar. A genotype having an average score ranging from 00–35 in 0–9 scale was considered resistant against spot blotch. The susceptible checks served as control. The per cent leaf blight resistant entries in different zones were in the range of 0.0–49.6%. The highest resistant entries (49.6%) were in north western plains zone (NWPZ), followed by north eastern plains zone (NEPZ) (24.6%), northern hills zone (NHZ) (18.6%), central zone (CZ) (2.3%) and southern hills zone (SHZ)(0.0%). The per cent entries showing resistance to leaf blight + three rusts, two rusts, one rust or no resistance to rusts were 27.8, 28.0, 26.8 and 14.0%, respectively. Out of these, the entries possessing resistance to leaf blight + stem rust, leaf blight+ leaf rust (north), leaf blight+ leaf rust (south) and leaf blight+ stripe rust were 52.2, 75.0, 63.8 and 60.7%, respectively. The above data indicated that leaf blight resistance may be achieved along with rust resistance in wheat and triticales and such possibility is more in case of leaf and stripe rusts as compared to stem rust. The combined resistance to leaf rust and spot blotch will be quite effective in containing the losses in yield and quality in wheat in north eastern plains zone in particular as well as increase the yield in other zones. The supply of data of pre-coordinated entries on status of resistance of entries of wheat and triticale has given choice to the breeders of better selection and proposing entries in coordinated yield trials.
