Incidence of black point (Alternaria sp.) in elite advanced bread wheat (Triticum aestivum) lines

Abstract

Eighty four elite advanced bread wheat lines were evaluated for resistance to black point during the crop season 2015-2016 at the Norman E. Borlaug Experimental Station in the Yaqui Valley, Mexico. Sowing dates were November 12, 19 and 26, 2015. Harvest and threshing were done manually in ten spikes per line, and the evaluation by visual inspection, counting healthy and infected grains to calculate the percentage of infection. The range of infection for the first sowing date was 0 to 19.8 %, with an average of 1.9; thirty nine lines did not show infected grains; for the second date it was 0 to 32.7 %, with an average of 4.8; twenty seven lines did not show infected grains; while for the third date, it was 0 to 44.9 % with an average of 6.8, and eighteen lines did not show infected grains. Eight lines did not show infected grains in the three dates. Lines with the highest average percentage of infection were: WHEAR/KUKUNA/3/C80.1/3* BATAVIA//2*WBLL1*2/4/WBLL1/KUKUNA//TACUPETOF2001/3/UP2338*2/VIVITSI with 20.8, and WAXWING*2/ KRONSTADF2004/3/TRCH/SRTU//KACHU/4/SAUAL/YANAC//SAUAL with 20.5%. Within the infection categories based on the average of the three dates, thirty lines were within the 0.1-2.5 % infection category, fourteen within 2.6-5.0 %, twenty three within 5.1-10.0 %, and nine lines within 10.1-30.0 %. The infection average of the group was 4.5 % with a range of 0 to 20.8 %, but some lines showed high percentage of infection in the dates, like WHEAR/KUKUNA/3/C80.1/3*BATAVIA//2*WBLL1*2/4/WBLL1/KUKUNA//TACUPETOF2001/3/UP2338*2/ VIVITSI, WAXWING*2/KRONSTADF2004/3/TRCH/SRTU//KACHU/4/SAUAL/YANAC//SAUAL, and BAV92//IRENA/ KAUZ/3/HUITES/4/DOLL/5/SERI.1B//KAUZ/HEVO/3/AMAD*2/4/KIRITATI with 44.9, 44.7, and 37.1 %, respectively, in the third date.