Zhikang Li

• Doctor of Philosophy
• Principal Investigator (Guest Professor) at Anhui Agricultural University

Breeding of rice varieties with low carbon dioxide equivalent (CO2e) emission is essential in reducing global greenhouse gas (GHG) emissions. In this study, we compared the gross CO2e emission of two newly developed green super rice (GSR) varieties with elite hybrids and nationally released farmer-cultivated varieties from production to post-produc...

Graph-based pangenome is gaining more popularity than linear pangenome because it stores more comprehensive information of variations. However, traditional linear genome browser has its own advantages, especially the tremendous resources accumulated historically. With the fast-growing number of individual genomes and their annotations available, th...

Cation exchanger (CAX) genes play an important role in plant growth/development and response to biotic and abiotic stresses. Here, we tried to obtain important information on the functionalities and phenotypic effects of CAX gene family by systematic analyses of their expression patterns, genetic diversity (gene CDS haplotypes, structural variation...

By using PacBio HiFi technology, we produced over 700 Gb of long-read sequencing (LRS) raw data; and by using Illumina paired-end whole-genome shotgun (WGS) sequencing technology, we generated more than 70 Gb of short-read sequencing (SRS) data. With LRS data, we assembled one genome and then generate a set of annotation data for an early-matured G...

CAX genes play an important role in plant growth/development and response to biotic and abiotic stresses. Here, we tried to obtain important information on the functionalities and phenotypic effects of CAX gene family by systematic analyses of their expression patterns, genetic diversity (gene CDS haplotypes, structural variations, gene presence/ab...

RNA‐binding proteins (RBPs) are components of the post‐transcriptional regulatory system, but their regulatory effects on complex traits remain unknown. Using an integrated strategy involving map‐based cloning, functional characterizations, and transcriptomic and population genomic analyses, we revealed that RBP‐K (LOC_Os08g23120), RBP‐A (LOC_Os11g...

Milling quality (MQ) and grain shape (GS) of rice (Oryza sativa L.) are correlated traits, both determine farmers’ final profit. More than one population under multiple environments may provide valuable information for breeding selection on these MQ-GS correlations. However, suitable analytical methods for reciprocal introgression lines with linkag...

Background Salinity is one of the main abiotic factors that restrict plant growth, physiology, and crop productivity is salt stress. About 33% of the total irrigated land suffers from severe salinity because of intensive underground water extraction and irrigation with brackish water. Thus, it is important to understand the genetic mechanism and id...

Background The amino acid content (AAC) of the rice grain is one of the most important determinants of nutritional quality in rice. Understanding the genetic basis of grain AAC and mining favorable alleles of target genes for AAC are important for developing new cultivars with improved nutritional quality. Results Using a diverse panel of 164 acce...

Glutamate-like receptor (GLR) genes are a group of regulatory genes involved in many physiological processes of plants. With 26 members in the rice genome, the functionalities of most rice GLR genes remain unknown. To facilitate their potential uses in rice improvement, an integrated strategy involving CRISPR-Cas9 mediated knockouts, deep mining an...

Milling quality (MQ) and grain shape (GS) of rice ( Oryza sativa L.) are correlated traits and both determining farmers’ final profit. More than one population under multiple environments may provide valuable information for breeding selection on this MQ-GS correlations. However, suitable analytical methods for reciprocal introgression lines with l...

Introduction Saline-alkali stress is one of the main abiotic factors limiting rice production worldwide. With the widespread use of rice direct seeding technology, it has become increasingly important to improve rice saline-alkali tolerance at the germination stage. Methods To understand the genetic basis of saline-alkali tolerance and facilitate...

The plant hormone abscisic acid (ABA) is crucial for plant seed germination and abiotic stress tolerance. However, the association between ABA sensitivity and plant abiotic stress tolerance remains largely unknown. In this study, 436 rice accessions were assessed for their sensitivity to ABA during seed germination. The considerable diversity in AB...

Auxin is an important phytohormone in plants, and auxin signaling pathways in rice play key roles in regulating its growth, development, and productivity. To investigate how rice grain yield traits are regulated by auxin signaling pathways and to facilitate their application in rice improvement, we validated the functional relationships among regul...

Introduction Drought and submergence are contrasting abiotic stresses that often occur in the same rice crop season and cause complete crop failure in many rain-fed lowland areas of Asia. Methods To develop rice varieties with good tolerances to drought and submergence, 260 introgression lines (ILs) selected for drought tolerance (DT) from nine BC...

Single nucleotide polymorphism (SNP) genotyping arrays provide an optimal high-throughput platform for genetic research and molecular breeding programs in both animals and plants. In this study, a high-quality and custom-designed Rice3K56 SNP array was developed with the resequencing data of 3024 rice accessions worldwide, which was then tested ext...

Plant height (PH) in rice (Oryza sativa) is an important trait for its adaptation and agricultural performance. Discovery of the semi-dwarf1 (SD1) mutation initiated the Green Revolution, boosting rice yield and fitness, but the underlying genetic regulation of PH in rice remains largely unknown. Here, we performed genome-wide association study (GW...

The stable performance of cultivars is a prerequisite for enhanced yield production to ensure food security. Identification of the stable yield performing genotype is the necessity of any breeding program to improve the livelihood of farmers. The present study was performed to evaluate the genotype and environment interaction of 22 green super rice...

Since its development and wide adoption in China, hybrid rice has reached the yield plateau for more than three decades. To understand the genetic basis of heterosis in rice and accelerate hybrid rice breeding, the yield performances of the elite rice hybrid, Quan-you-si-miao (QYSM) were genetically dissected by whole-genome sequencing, large-scale...

Optimum growing temperature is necessary for maximum yield-potential in any crop. The global atmospheric temperature is changing more rapidly and irregularly every year. High temperature at the flowering/reproductive stage in rice causes partial to complete pollen sterility, resulting in significant reduction in grain yield. Green Super Rice (GSR)...

Key message Novel alleles of two reported tiller angle genes and eleven candidate genes for rice tiller angle were identified by combining GWAS with transcriptomic, qRT-PCR and haplotype analysis. Abstract Rice tiller angle is a key agronomic trait determining rice grain yield. Several quantitative trait loci (QTLs) affecting rice tiller angle hav...

Introduction: Rice, Oryza sativa L. (Os), is one of the oldest domesticated cereals that has also gone through extensive improvement in modern breeding. Objectives: How rice was domesticated and impacted by modern breeding. Methods: We performed comprehensive analyses of genomic sequences of 504 accessions of Os and 456 accessions of O. rufipogon...

Glycerolipids are essential for rice development and grain quality but its genetic regulation remains unknown. Here, we report its genetic base using metabolite-based genome-wide association study (mGWAS) and metabolite-based quantitative traits locus (mQTL) analyses based on lipidomic profiles of seeds from 587 Asian cultivated rice accessions and...

Grain size is one of the essential determinants of rice yield. Our previous studies revealed that ethylene plays an important role in grain size control; however, the precise mechanism remains to be determined. Here, we report that the ethylene response factor OsERF115 functions as a key downstream regulator for ethylene‐mediated grain development....

The power of selection and phenotypic plasticity of seven rice grain yield (GY) traits was dissected using DNA markers and 226 Minghui86 introgression lines (ILs) phenotyped across four contrast environments of long‐day versus short‐day and drought versus irrigated conditions. Linkage mapping identified 77 main‐effect quantitative trait loci (QTLs)...

The concept of a pan-genome, which is the collection of all genomes from a population, has shown great potential in genomics study, especially for crop sciences. The rice pan-genome constructed from the second-generation sequencing (SGS) data is about 270 Mb larger than Nipponbare, the rice reference genome (NipRG), but it still suffers from incomp...

Optimum soil water availability is vital for maximum yield production in rice which is challenged by increasing spells of drought. The reproductive stage drought is among the main limiting factors leading to the drastic reduction in grain yield. The objective of this study was to investigate the molecular and morphophysiological responses of pre-an...

Multiple stress tolerance at the seed germination stage is crucial for better crop establishment in the direct-seeded rice ecosystem. Therefore, identifying rice genes/quantitative trait loci (QTLs) associated with salinity and anaerobic tolerance at the germination stage is a prerequisite for adaptive breeding. Here, we studied 498 highly diverse...

N⁶-methyladenosine (m⁶A) methylation represents a new layer of the epitranscriptomic regulation of plant development and growth. However, the effects of m⁶A on rice responses to environmental stimuli remain unclear. In this study, we performed a methylated-RNA immunoprecipitation sequencing analysis and compared the changes in m⁶A methylation and g...

Rice tiller angle is a key agronomic trait determining rice grain yield. Several quantitative trait loci (QTLs) affecting rice tiller angle have been mapped in the past decades. little is known about the genetic base of tiller angle in rice, because rice tiller angle is a complex polygenic trait. In this study, we performed genome-wide association...

Achieving sufficient food with finite resources and leaving lesser impact on the environment to feed the growing global population has always been a great challenge. Here we review the concept and practices of Green Super Rice (GSR) that has led to a paradigm shift in the goals of crop genetic improvement and models of food production for promoting...

Panicle architecture is one of the major factors influencing productivity of rice crops. The regulatory mechanisms underlying this complex trait are still unclear and genetic resources for rice breeders to improve panicle architecture are limited. Here, we have performed a genome-wide association study (GWAS) to analyze and identify genetic determi...

Rice remains a major staple food source for the rapidly growing world population. However, regular occurrences of carcinogenic arsenic (As) minerals in waterlogged paddy topsoil pose a great threat to rice production and consumers across the globe. Although As contamination in rice has been well recognized over the past two decades, no suitable ric...

Interactions and co‐evolution between plants and herbivorous insects are critically important in agriculture. Brown planthopper (BPH) is the most severe insect of rice, and the biotypes adapt to feed on different rice genotypes. Here, we present genomics analyses on 1,520 global rice germplasms for resistance to three BPH biotypes. Genome‐wide asso...

Gibberellin 2-oxidase (GA2ox) plays an important role in the GA catabolic pathway and the molecular function of the OsGA2ox genes in plant abiotic stress tolerance remains largely unknown. In this study, we functionally characterized the rice gibberellin 2-oxidase 8 (OsGA2ox8) gene. The OsGA2ox8 protein was localized in the nucleus, cell membrane,...

A one-/two-dimensional genome-wide association study (GWAS) strategy was adopted to investigate the genetic systems underlying the reciprocal adaptation of rice (Oryza sativa) and its bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo) using the whole-genome sequencing and large-scale phenotyping data of 701 rice accessions and 23 diverse Xoo s...

The frequent fluctuations in global climate variability (GCV), decreases in farmland and irrigation water, soil degradation and erosion, and increasing fertilizer costs are the significant factors in declining rice productivity, mainly in Asia and Africa. Under GCV scenarios, it is a challenging task to meet the rice food demand of the growing popu...

Low-temperature stress (LTS) is one of the major abiotic stresses that affect crop growth and ultimately decrease grain yield. The development of rice varieties with low-temperature stress tolerance has been a severe challenge for rice breeders for a long time. The lack of consistency of the quantitative trait loci (QTLs) governing LTS tolerance fo...

Nitrogen is one of the most important nutrients for rice growth and development. Breeding of nitrogen deficiency tolerance (NDT) variety is considered to be the most economic measure to solve the constrain of low nitrogen stress on grain yield in rice. An interconnected breeding (IB) population of 497 lines developed using Huanghuazhan (HHZ) as the...

Future demands for increased productivity and resilience to abiotic/biotic stresses of major crops require new technologies of breeding by design (BBD) built on massive information from functional and population genomics research. A novel strategy of breeding by selective introgression (BBSI) has been proposed and practiced for simultaneous improve...

Integration of transcriptomics and metabolomics data can provide detailed information for better understanding the molecular mechanisms underlying salt tolerance in rice. In the present study, we report a comprehensive analysis of the transcriptome and metabolome of rice overexpressing the OsDRAP1 gene, which encodes an ERF transcription factor and...

The polymorphisms within the gene coding regions represent the most important part of the overall genetic diversity in rice. We characterized the gene-CDS-haplotype (gcHap) diversity of 45,963 rice genes in 3,010 rice accessions. With an average 226±390 gcHaps per gene in rice populations, all rice genes could be classified into three main categori...

High salinity is one of the major abiotic stresses limiting rice production. Melatonin has been implicated in the salt tolerance of rice. However, the molecular basis of melatonin-mediated salt tolerance in rice remains unclear. In the present study, we performed an integrated transcriptome and metabolome profiling of rice seedlings treated with sa...

Background Bacterial blight, which is caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease worldwide. Rice introgression line H471, derived from the recurrent parent Huang-Hua-Zhan (HHZ) and the donor parent PSBRC28, exhibits broad-spectrum resistance to Xoo, including to the highly virulent Xoo strain PXO99A, whereas its pa...

Dominant early heading (DEH) in rice (Oryza sativa L.) is of interest in both breeding and genetics. The genetic mechanisms underlying DEH have remained largely unclear. We have developed a near-isogenic DEH line without yield drag named DEH_229 by sister-line backcross (BC) breeding with MH63, a restorer, as the genetic background. We conducted a...

Weed competitive ability (WCA) is vital for the improvement of grain yield under direct-seeded and aerobic rice ecosystems where weeds are a major limiting factor. Early seed germination (ESG) and early seedling vigor (ESV) are the crucial traits for WCA. This study attempted to map the quantitative trait loci (QTLs) and hotspot regions governing E...

Rice black-streaked dwarf disease (RBSDD) caused by rice black-streaked dwarf virus (RBSDV) is one of the most destructive viral diseases of rice. Thus, it is imperative that resistant rice germplasms are screened for novel RBSDV-resistant genes. The RBSDV resistance of a diverse global collection comprising 1,953 rice accessions was evaluated unde...

Background: High soil salinity can cause significant losses in rice productivity worldwide, mainly because salt inhibits plant growth and reduces grain yield. To cope with environmental changes, plants have evolved several adaptive mechanisms that involve the regulation of many stress-responsive genes. Results: In this study, we identified OsSTA...

Background: Bacterial blight, which is caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease worldwide. Rice introgression line H471, derived from the recurrent parent Huang-Hua-Zhan (HHZ) and the donor parent PSBRC28, exhibits broad-spectrum resistance to Xoo, including to the highly virulent Xoo strain PXO99A, whereas its p...

Background: Bacterial blight, which is caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease worldwide. Rice introgression line H471, derived from the recurrent parent Huang-Hua-Zhan (HHZ) and the donor parent PSBRC28, exhibits broad-spectrum resistance to Xoo, including to the highly virulent Xoo strain PXO99A, whereas its p...

Background: Bacterial blight, which is caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease worldwide. Rice introgression line H471, derived from the recurrent parent Huang-Hua-Zhan (HHZ) and the donor parent PSBRC28, exhibits broad-spectrum resistance to Xoo, including to the highly virulent Xoo strain PXO99A, whereas its p...

Key message: The "Green Super Rice" (GSR) project aims to fundamentally transform crop production techniques and promote the development of green agriculture based on functional genomics and breeding of GSR varieties by whole-genome breeding platforms. Rice (Oryza sativa L.) is one of the leading food crops of the world, and the safe production of...

Over the last few years, pangenome analyses have been applied to eukaryotes, especially to important crops. A handful of eukaryotic pangenome studies have demonstrated widespread variation in gene presence/absence among plant species and its implications on agronomically important traits. In this chapter, we focus on the methodology of pangenome an...

The article Genomic Breeding of Green Super Rice Varieties and Their Deployment in Asia and Africa.

An attempt was made in the current study to identify the main-effect and co-localized quantitative trait loci (QTLs) for germination and early seedling growth traits under low-temperature stress (LTS) conditions in rice. The plant material used in this study was an early backcross population of 230 introgression lines (ILs) in BCIF7 generation deri...

Key message OsPUB67, a U-box E3 ubiquitin ligase, may interact with two drought tolerance negative regulators (OsRZFP34 and OsDIS1) and improve drought tolerance by enhancing the reactive oxygen scavenging ability and stomatal closure. Abstract E3 ubiquitin ligases are major components of the ubiquitination cascade and contribute to the biotic and...

Grain shape is a very important goal in the rice breeding program nowadays. Underlying the genetic basis of grain shape would largely speed the breeding process. In the present study, a diverse panel of 1016 rice accessions from 70 countries and areas worldwide were evaluated for their grain shapes. There were large variations for all three grain s...

Rice is the most important staple food crop, and it feeds more than half of the world population. Brown planthopper (BPH) is a major insect pest of rice that causes 20–80% yield loss through direct and indirect damage. The identification and use of BPH resistance genes can efficiently manage BPH. A molecular marker-based genetic analysis of BPH res...

Rice (Oryza sativa L.) not only provides insurance covering global food security but also works as a model for plant research. Currently, with overwhelmingly accumulated sequencing data, various databases were constructed for different target users, including: the Genome Variation Map (Song et al., 2018), RiceVarMap (Zhao et al., 2015), SNP‐Seek da...

Background: Arsenic (As) is an unwanted toxic mineral that threatens the major rice-growing regions in the world, especially in South Asia. Rice production in Bangladesh and India depends on As-contaminated groundwater sources for irrigating paddy fields, resulting in elevated amounts of As in the topsoil. Arsenic accumulating in rice plants has a...

The production and productivity of rice (Oryza sativa L.) are primarily influenced by the application of the critical nutrients nitrogen (N), phosphorus (P), and potassium (K). However, excessive application of these fertilizers is detrimental to the environment and increases the cost of production. Hence, there is a need to develop varieties that...

Hybrid breeding is the main strategy for improving productivity in many crops, especially in rice and maize. Genomic hybrid breeding is a technology that uses whole genome markers to predict future hybrids. Predicted superior hybrids are then field evaluated and released as new hybrid cultivars after their superior performances are confirmed. This...

The development of green super rice varieties with improved nutrient use efficiency (NuUE) is a vital target area to increase yield and make it more stable under rainfed conditions. In the present study, we followed an early backcross (BC) breeding approach by using a high-yielding and widely adapted Xian variety, Weed Tolerant Rice 1 (WTR-1), as a...

Seedling vigour (SV) is important for direct seeding rice (Oryza sativa L.), especially in a paddy-direct seeding system, but the genetic mechanisms behind the related traits remain largely unknown. Here, we used 744 germplasms, having at least two subsets, for the detection of quantitative trait loci (QTLs) affecting the SV-related traits tiller n...