Use of four Sclerotinia sclerotiorum isolates of different aggressiveness, three inoculations per plant, and delayed multiple evaluations to select common beans with high levels of white mold resistance

作者：Viteri Diego M^*; Otto Kristen; Teran Henry; Schwartz Howard F; Singh Shree P

来源：Euphytica, 2015, 204(2): 457-472.

DOI：10.1007/s10681-015-1366-7

• Breeding for resistance
• Phaseolus vulgaris L.
• P. coccineus L.
• Sclerotinia sclerotiorum (Lib.) de Bary

White mold is a severe disease of common bean worldwide. Partial resistance occurs in the primary and secondary gene pools. Factors essential for identifying high levels of resistance that is effective throughout the growing season are not known. Our objectives were to determine which factors are most essential for identifying high levels of resistance including: (i) pathogen isolates screened, (ii) inoculations/plant, (iii) evaluation dates, (iv) area under disease progress curve (AUDPC), and (v) the SCAR markers linked with WM2.2, WM6.1, WM7.1, WM7.3, and WM8.3 resistance QTL. Thirty-one genotypes were inoculated one to three times/plant with ARS12D and ND710 isolates in the greenhouse in Idaho, and CO467 and NY133 in Colorado. Evaluations were made from 7 to 35 days post-inoculation. Disease severity and AUDPC increased until 21 days in Colorado and 35 days in Idaho. Correlations were positive among isolates at each evaluation date. The presence or absence of white mold resistance QTL was not indicative of resistance response. 'Othello' was susceptible to all isolates with one inoculation, and VC13-5 was resistant to three isolates and intermediate to ND710 after three inoculations per plant; both of these genotypes lacked the five resistance QTL. SE155-9 with WM2.2, WM7.1, and WM8.3 QTL was resistant to CO467 and NY133. However, SE152-6 with the same QTL was resistant and possessed lower AUDPC values to all isolates after three inoculations. Thus, screening with four isolates, three inoculations/plant, and disease evaluations delayed until 21 days or longer helped identify genotypes with high levels of broad-spectrum resistance.

• 出版日期2015-7