Minor Differences in Anther Extrusion Affect Resistance to Fusarium Head Blight in Wheat

Abstract

Fusarium head blight (FHB) remains a serious problem due to yield loss and mycotoxin accumulation in wheat production worldwide. We previously reported that the closed‐flowering (no anther extrusion) characteristic was effective for increasing resistance to FHB infection. In this study, we investigated the relationships between the degree of anther extrusion (AE) and FHB damage using double haploid lines (DHLs), derived from F1 plants from crosses between closed‐flowering and opened‐flowering varieties. These DHLs exhibited various degrees of AE, and the degree of AE was significantly different among DHLs, regardless of the year and environment (pot‐ or field‐grown). FHB severity was the lowest in closed‐flowering DHLs, and DHLs with partially extruded anthers showed significantly higher FHB symptoms than those with closed‐flowering phenotypes. In general, DHLs with partially extruded anthers also had relatively severe FHB symptoms compared with those exhibiting full anther extrusion. FHB severity was significantly correlated with Fusarium‐damaged kernels and deoxynivalenol concentration. The results of this study showed that partially extruded anthers were considered to be a source of FHB infection. The closed‐flowering phenotype improved resistance to FHB infection. Meanwhile, phenotypes with rapid anther extrusion and ejection also could contribute to the avoidance of FHB infection.

Comparison of Fusarium head blight resistance in cytoplasmic male sterile, maintainer and restorer lines in winter wheat

“…This resistance is one of two major categories of resistance to FHB: resistance to initial infection (Type I), and resistance to pathogen spread in infected tissue (Type II) (Shroeder and Christensen 1963). Our results are in agreement with those of Kubo et al (2010Kubo et al ( , 2013 who found the severity of FHB infection in cleistogamous (closed flowering) recombinant inbred lines (RILs) and double haploid lines (DHLs) of wheat to be significantly lower than in chasmogamous (opened flowering) RILs and DHLs, hence demonstrating that the closed-flowering (no anther extrusion) characteristic was effective in increasing resistance to FHB infection. In their experiments, the lines set seed, hence seed set did not affect disease severity (as may have occurred in our experiments).…”

“…The three lines all set seed, so the presence of seed may explain our results. The three fertile anther lines which set seed all had higher disease severity than the CMS lines which did not set seed, however, previous research by Kubo et al (2010Kubo et al ( , 2013 indicated seed setting did not affect disease severity. Seed setting alone may not fully explain our results.…”

“…Kubo et al (2010) found that cleistogamous lines initially had reduced FHB infection, but chasmogamous lines were not different for kernel shriveling or mycotoxin levels. Furthermore, Kubo et al (2013) found minor differences in anther extrusion affected FHB resistance in wheat. In this study, again, lines with cleistogamous flowers had lower FHB symptoms, as did lines with rapid anther extrusion.…”

Evaluation of Fusarium Head Blight Resistance in Wheat and the Development of a New Variety by Integrating Type I and II Resistance

“…Skinnes et al also demonstrated that even low anther extrusion is correlated with susceptibility to FHB infection 43 . Therefore, careful long-term observation from flowering to grain filling is required to select plants with complete cleistogamy 21 .…”

Characterization of the Relationships between Wheat Cultivars, Fusarium Head Blight, and Mycoflora Grains

“…This trait was not correlated to grain colonization or FHB resistance (results not shown). However, even little differences in anther extrusion can have a signifi cant impact on the susceptibility of the variety [17]. In a future investigation, the role of anthers on mycofl ora of grains has to be considered.…”