Simultaneously improving Fusarium head blight (FHB) resistance and grain yield is challenging in wheat breeding. The correlations between spikelet compactness (SC), grain number per spike (GNS), thousand-grain weight (TGW) and FHB resistance remains unclear in common wheat. Identification of major quantitative trait loci (QTL) conferring FHB resistance and yield components, and development of breeder-friendly markers for the QTL are prerequisites for marker-assisted selection (MAS). Here, a recombinant inbred line (RIL) population derived from a cross between a resistant cultivar Yangmai 12 (YM12) and a susceptible cultivar Yanzhan 1 (YZ1) was used to map QTL for FHB resistance and yield components. A total of 22 QTL were identified; among these, six are likely to be new for corresponding traits. A QTL cluster (Qclu.yas-2D) for FHB type Ⅱ resistance, SC, GNS, and TGW was detected on chromosome 2D. Breeder-friendly kompetitive allele-specific PCR (KASP) markers flanking the interval of Qclu.yas-2D were developed and validated in a diverse panel of 166 wheat cultivars and advanced lines. The YM12 alleles of Qclu.yas-2D significantly increased FHB resistance, SC, and GNS but decreased TGW in the validation population. The KASP markers developed for Qclu.yas-2D have great potential for breeding high-yielding wheat cultivars with enhanced FHB resistance.

The MADS-box gene plays an important role in regulating plant growth and development. In this study, a SEP3-like MADS-box gene TaSEP3-1 was isolated from bread wheat. The expression patterns of the three homoeologs TaSEP3-A1, TaSEP3-B1, and TaSEP3-D1 were similar, and higher expression levels were detected in floral organs and developing kernels. TaSEP3-D1 was located in the nucleus and cytoplasm and possessed transactivation activity in yeast. Homoeolog sequence polymorphism analysis identified four, three, and four haplotypes of TaSEP3-A1, TaSEP3-B1, and TaSEP3-D1, respectively, and the haplotypes of TaSEP3-D1 had larger effects on agronomic traits than those of TaSEP3-A1 and TaSEP3-B1. D1_h4, significantly associated with heading date, plant height, and other yield-related traits, was the favored haplotype of TaSEP3-D1. Transgenic wheat genotypes overexpressing TaSEP3-D1 exhibited delayed heading and reduced plant height, indicating a role in regulating heading date and plant development. These results shed light on the role of TaSEP3-D1 in wheat plant development. The favored haplotype of TaSEP3-D1 can be applied in breeding to improve plant architecture and yield in wheat.

Plant germplasm underpins much of crop genetic improvement. Millions of germplasm accessions have been collected and conserved ex situ and/or in situ, and the major challenge is now how to exploit and utilize this abundant resource. Genomics-based plant germplasm research (GPGR) or “Genoplasmics” is a novel cross-disciplinary research field that seeks to apply the principles and techniques of genomics to germplasm research. We describe in this paper the concept, strategy, and approach behind GPGR, and summarize current progress in the areas of the definition and construction of core collections, enhancement of germplasm with core collections, and gene discovery from core collections. GPGR is opening a new era in germplasm research. The contribution, progress and achievements of GPGR in the future are predicted.

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most destructive wheat (Triticum aestivum L.) diseases worldwide. Identification of quantitative trait loci (QTL) conferring FHB resistance followed by marker assisted selection (MAS) is an efficient approach to breed FHB-resistant varieties. In this study, 38 additive QTL and 18 pairs of epistatic QTL for FHB resistance were detected in four environments using a population of recombinant inbred lines (RILs) derived from varieties Neixiang 188 and Yanzhan 1. Six QTL clusters were located on chromosomes 2D, 4B, 4D, 5A, 5D and 7B, suggesting possible polytrophic functions. Six elite lines with good FHB resistance and agronomic traits were selected from the same population using the associated markers. Our results suggest that MAS of multiple QTL will be effective and efficient in wheat breeding.