High-quality genome assembly of the soybean fungal pathogen Cercospora kikuchii

Molecular Breeding to Overcome Biotic Stresses in Soybean: Update

Soybean (Glycine max (L.) Merr.) is an important leguminous crop and biotic stresses are a global concern for soybean growers. In recent decades, significant development has been carried outtowards identification of the diseases caused by pathogens, sources of resistance and determination of loci conferring resistance to different diseases on linkage maps of soybean. Host-plant resistance is generally accepted as the bestsolution because of its role in the management of environmental and economic conditions of farmers owing to low input in terms of chemicals. The main objectives of soybean crop improvement are based on the identification of sources of resistance or tolerance against various biotic as well as abiotic stresses and utilization of these sources for further hybridization and transgenic processes for development of new cultivars for stress management. The focus of the present review is to summarize genetic aspects of various diseases caused by pathogens in soybean and molecular breeding research work conducted to date.

High-Quality Genome Assembly of Olea europaea subsp. cuspidata Provides Insights Into Its Resistance to Fungal Diseases in the Summer Rain Belt in East Asia

The olive tree (Olea europaea L.) is the most iconic fruit crop of the Mediterranean Basin. Since the plant was introduced to China in the 1960s, the summer rain climate makes it susceptible to pathogens, leading to some olive diseases. Olea europaea L. subsp. cuspidata is natively distributed in the Yunnan province of China. It has a smaller fruit size, lower oil content, and higher resistance compared to subsp. europaea, which makes subsp. cuspidata a critical germplasm resource to be investigated. Here, a high-quality genome of subsp. cuspidata with 1.38 Gb in size was assembled and anchored onto 23 pseudochromosomes with a mounting rate of 85.57%. It represents 96.6% completeness [benchmarking universal single-copy orthologs (BUSCO)] with a contig N50 of 14.72 Mb and a scaffold N50 of 52.68 Mb, which shows a significant improvement compared with other olive genomes assembled. The evaluation of the genome assembly showed that 92.31% of resequencing reads and an average of 96.52% of assembled transcripts could be aligned to the assembled genome. We found that a positively selected gene, evm.model.Chr16.1133, was shared with the results of transcriptome analysis. This gene belongs to the susceptible gene and negatively regulates the disease resistance process. Furthermore, we identified the Cercospora genus which causes the leaf spot disease in the infected leaves. The high-quality chromosome-level genomic information presented here may facilitate the conservation and utilization of germplasm resources of this subspecies and provide an essential genetic basis for further research into the differences in oil content and resistance between subsp. cuspidata and europaea.