(go to KOMUGI Home) (go to WIS List) (go to NO.92 Contents)

Wheat Information Service
Number 92: 27-29 (2001)
Research information


Loose smut resistant lines in wheat and triticale with combined resistance to Karnal bunt, rusts, powdery mildew and leaf blight

D. P. Singh1, A. K. Sharma1 and A. 8. Grewal2

1Crop Protection Programme, Directorate of Wheat Research, P.B.No.158, Karnal 132 001, India
2Department of Plant Pathology, P.A.U. Ludhiana 141 004, India


Loose smut caused by Ustilago segetum (Pres.) Russel var. tritici (Jensen) is one of the major diseases of wheat in northern India and is responsible for about 1-5 % yield losses every year, on an average (Joshi et al. 1988). The disease is totally seedborn and can easily be controlled by seed treatment with systemic fungicides like carboxin, carbendazim and tebuconazole (Chatrath et al. 1969; Bahadur and Sinha 1978; Sinha and Singh 1996). However, chemical usage has its own drawbacks and till date the adoption of these fungicides by the farmers is not up to the desired level, mainly due to the high cost of fungicides coupled with other issues like non availability of fungicides at proper time, unsuitable packing quantity and above all unfitness of treated left over seeds for consumption. The issues of health and environmental hazards are also drawing attention and pressing for restricted uses of pesticides in agriculture. Keeping these problems in view, efforts were made by some workers in past to identify resistant lines for loose smut (AujIa et al. 1990; Srivastava et al. 1992; Beniwal et al. 1998). However, such lines were not utilized extensively by the breeders since resistance to loose smut alone does not carry much significance in wheat since resistance to diseases like rusts and leaf blight is on the first priority of the wheat breeders. The present study was, therefore, done with an object to evaluate the wheat and triticale lines possessing resistance to other major diseases like rusts, Karnal bunt, powdery mildew and leaf blight, against loose smut, under artificially inoculated conditions so as to identify resistant sources that carry resistance to loose smut along with resistance to other important diseases.

The confirmed resistant lines of wheat and triticale to one or more diseases like rusts, Karnal bunt, powdery mildew and moderately resistant to leaf blight, were tested for their resistance to loose smut disease under artificially inoculated conditions. In all, 132 lines of wheat and triticale, were tested under artificially inoculated conditions. 0ut of these, 50 were resistant to rusts, 60 to Karnal bunt, 14 to leaf blight and 8 to powdery mildew since the past few years (5 or more years) at multilocation hot spot testing. The lines were sown in 2 m long rows during November and five ear heads of each entry were inoculated at growth stage '59' of Zadoks' scale (Zadoks et al. 1974) artificially with loose smut teliospores using modified 'Go-go'method (Joshi et al. 1988), during 1997-98 crop season, at Ludhiana. The inoculated ear heads were tagged and harvested separately. The seeds obtained from such inoculated ear heads were planted during next crop season i. e. 1998-99 and record on smutted and healthy ear heads was taken on tiller basis after ear emergence. The percent loose smut infection was calculated. The entries having 0-5 % loose smut infection, under artificially inoculated conditions were categorized as resistant whereas those showing >5 % infection were identified as susceptible to loose smut.

This work was done under All India Coordinated Wheat Improvement Project, Contribution, No. 60/DWR/ 2000- 01. E-mail: dwr@vsnl.com, Fax: +91-184-251390

-->Next

(go to KOMUGI Home) (go to WIS List) (go to NO.92 Contents)