SCREENING OF SUNFLOWER GERMPLASM FOR RESISTANCE TO ALTERNARIA LEAF SPOT

Abstract

Leaf spot of sunflower caused by Alternaria helianthi has been
considered as a potentially destructive disease of sunflower all over
the world (Allen et aI" 1983; Balasubramhanyam and KoIte, 1980;
Reddy and Gupta, 1977), Yield losses as high as 80 per cent have
been reported under favourable weather conditions in India due
to this disease (Agrawath et ai" 1979; Balasubrahmanyam and KoIte,
1980). Though destructive levels of Alternaria leaf spot have been
reported in India, no concerted efforts were made to screen the
available germplasm systematically to locate the field resistence,
as no resistant sources are available against this disease both in
cultivated as well as in related wild species of Helianthus (Morris
et ai.,1983). Significant genetic variability to Alternaria leaf spot has,
however, been reported in sunflower (Agrawath et ai., 1979; Carson,
1985; Nagaraju et ai., 1992a),