Screening for resistance to Aspergillus flavus invasion and aflatoxin production in peanut
摘要
Aflatoxin contamination, primarily caused by Aspergillus flavus invasion, poses significant risks to food and seed safety in peanut. This study aimed to evaluate the resistance of various peanut genotypes to A. flavus infection and subsequent aflatoxin production, addressing the need for effective breeding strategies to enhance resistance. A total of 227 peanut germplasm materials, including 172 cultivars, 29 breeding lines, and 26 wild accessions, were assessed for their response to A. flavus infection. The materials underwent artificial inoculation with a standard strain of A. flavus, followed by quantification of aflatoxin B1 (AFT B1) levels. Infection indices were calculated based on visual assessments of spore coverage, and genetic diversity was analyzed among selected materials. The evaluation identified one resistant entry (OPLX-86) (0.44%) and 88 moderately resistant entries (38.77%). The lowest AFT B1 levels were observed in OPLX-11 and 21L94 (11.25 μg/g). A significant positive correlation (r = 0.4748) was found between the infection index and AFT B1 content. Notably, wild peanut accessions demonstrated a higher proportion of moderately resistant and resistant genotypes compared to the cultigen (53.85% vs. 37.31%). Peanut cultivars developed in the central and southern regions in China tend to exhibit stronger resistance to A. flavus infection than those in northern region. Furthermore, resistance was not correlated with oleic or linoleic acid content, indicating that genetic improvements in these traits may not affect resistance to A. flavus. The findings highlight the importance of expanding screening efforts for resistance to A. flavus across diverse peanut germplasm to broaden the gene base for breeding programs. Future research should focus on utilizing wild accessions as valuable genetic resources in developing resistant peanut cultivars.