Natural incidence of black point (Alternaria sp.) in a group of elite advanced bread wheat (Triticum aestivum) lines

One hundred and sixty eight elite advanced bread wheat lines were evaluated for resistance to black point during the crop season 2014-2015 at the Norman E. Borlaug Experimental Station in the Yaqui Valley, Mexico. Sowing dates were November 19 and 28, and December 8, 2014. 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 34.6%, with an average of 2.7; sixty lines did not show infected grains; for the second date it was 0 to 43.6%, with an average of 3.1%; fifty lines did not show infected grains; while for the third date, it was 0 to 14.7%, and seventy one lines did not show infected grains. Five lines did not show infected grains in the three dates. Lines with the highest average percentage of infection were: WAXWING/KRONSTADF2004//2*FRNCLN with 18.6%, PFAU/MILAN/5/CHEN/AEGILOPS SQUARROSA (TAUS)//BCN/3/VEE#7/BOW/4/PASTOR/6/WHEAR/4/ SNI/TRAP#1/3/KAUZ*2/TRAP//KAUZ/5/C80.1/3*BATAVIA//2*WBLL1/7/C80.1/3*BATAVIA//2*WBLL1/5/REH/HARE//2*BCN/3/CROC_1/AE.SQUARROSA (213)//PGO/4/HUITES with 16.0, and WBLL1*2/BRAMBLING//SAAR/ 2*WAXWING/4/PBW343*2/KUKUNA//KRONSTAD F2004/3/PBW343*2/KUKUNA with 15.4%. Within the infection categories based on the average of the three dates, one hundred and twelve lines were within the 0.1-2.5% infection category, thirty one within 2.6-5.0%, thirteen within 5.1-10.0%, and seven lines within 10.1-30.0%. The infection average of the group was 2.3% with a range of 0 to 18.6%, but some lines showed high percentage of infection in the dates, like PFAU/MILAN/5/CHEN/AEGILOPSSQUARROSA(TAUS)//BCN/3/VEE#7/BOW/4/PASTOR/6/WHEAR/4/ SNI/TRAP#1/3/KAUZ*2/TRAP//KAUZ/5/C80.1/3*BATAVIA//2*WBLL1/7/C80.1/3*BATAVIA//2*WBLL1/5/REH/HARE//2*BCN/3/CROC_1/AE.SQUARROSA (213)//PGO/4/HUITES which showed 43.6% in the second date.