Enhanced grain yield has been achieved in bread wheat (Triticum aestivum L.) through development and cultivation of superior genotypes incorporating yield-related agronomic and physiological traits derived from genetically diverse and complementary genetic pool. Despite significant breeding progress, yield levels in wheat have remained relatively low and stagnant under marginal growing environments. There is a need for genetic improvement of wheat using yield-promoting morpho-physiological attributes and desired genotypes under the target production environments to meet the demand for food and feed. This review presents breeding progress in wheat for yield gains using agronomic and physiological traits. Further, the paper discusses globally available wheat genetic resources to identify and select promising genotypes possessing useful agronomic and physiological traits to enhance water, nutrient-, and radiation-use efficiency to improve grain yield potential and tolerance to abiotic stresses (i.e. elevated CO2, high temperature, and drought stresses). Finally, the paper highlights quantitative trait loci (QTL) linked to agronomic and physiological traits to aid breeding of high-performing wheat genotypes.

/pdf/agronomic-and-physiological-traits-and-associated-1hghsnnb0v.pdf

Agronomic and Physiological Traits, and Associated Quantitative Trait Loci (QTL) Affecting Yield Response in Wheat (Triticum aestivum L.): A Review.

The growth of wheat tillers and plant nitrogen-use efficiency (NUE) will gradually deteriorate in response to high plant density and over-application of N. Therefore, in this study, a 2-year field study was conducted with three levels of plant densities (75 ×104plants ha-1, D1; 300 ×104plants ha-1, D2; 525 ×104plants ha-1, D3) and three levels of N application rates (120 kg N ha-1, N1; 240 kg N ha-1, N2; 360 kg N ha-1, N3) to determine how to optimize plant density and N application to regulate tiller growth and to assess the contribution of such measures to enhancing grain yield (GY) and NUE. The results indicated that an increase in plant density significantly increased the number of superior tillers and the number of spikes per m2(SN), resulting in a higher GY and higher partial factor productivity of applied N (PFPN). However, there was no significant difference in GY and PFPN between plant densities D2 and D3. Increasing the N application rate significantly increased the vascular bundle number (NVB) and area (AVB), however, excess N application (N3) did not significantly improve these parameters. N application significantly increased GY, whereas there was a significant decrease in PFPN in response to an increase in N application rate. The two years results suggested that increasing the plant density (from 75 ×104plants ha-1to 336 ×104plants ha-1) in conjunction with the application of 290 kg N ha-1N will maximize GY, and also increase PFPN(39.7 kg kg-1), compared with the application of 360 kg N ha-1N. Therefore, an appropriate combination of increased planting density with reduced N application could regulate tiller number and favor the superior tiller group, to produce wheat populations with enhanced yield and NUE.

Optimizing plant density and nitrogen application to manipulate tiller growth and increase grain yield and nitrogen-use efficiency in winter wheat

Tillering contributes greatly to grain yield in wheat. Investigating the mechanisms of tillering provides a theoretical foundation and genetic resources for the molecular breeding of wheat. The regulation of tillering is a complex molecular process that involves a multitude of factors. Little is known about the molecular mechanisms in the wheat genome, although progress has been made in rice. Here we review the developmental characteristics of tillers and summarize current knowledge of the roles of endogenous and environmental factors in wheat tillering. We propose directions for future studies and advanced technologies to be used for gene identification and functional studies.

Genetic, hormonal, and environmental control of tillering in wheat

Plant hormones play important roles in regulating the occurrence of crop tillers. However, little is known about the relationships and the underlying mechanisms between endogenous hormones and the occurrence of wheat tillers induced by exogenous hormones. In this study, two winter wheat cultivars, Xinong 979 and Xiaoyan 22, were used to investigate the effects of the exogenous application of indole-3-acetic acid (IAA) and zeatin (Z) on the occurrence of wheat tillers and investigate underlying mechanisms regulating the occurrence of tillers. The results showed that the application of IAA inhibited the occurrence of tillers, and external Z application promoted the occurrence rate of tillers under low nitrogen conditions. Further analysis of the results showed that exogenous IAA completely inhibited the growth of tiller buds, while exogenous Z significantly promoted the growth rate of tiller buds in low nitrogen conditions. Endogenous hormones exhibit important functions in regulating the growth of tiller buds, which contents were affected by exogenous hormones. Furthermore, according to the principal component analysis and correlation analysis, the growth of tiller buds was significantly positively correlated with the content of endogenous Z, whereas it was significantly negatively correlated with the ratios of endogenous IAA to endogenous Z (IAA:Z) and endogenous abscisic acid (ABA) to endogenous Z (ABA:Z). Moreover, no significant correlation was observed between the growth of the tiller buds and the endogenous IAA, endogenous gibberellins (GAs), and endogenous ABA content. These results suggested that Z played key roles in regulating the tiller occurrence, and exogenous hormones regulated the growth of wheat tiller buds via affecting the Z contents, thus regulating the occurrence of wheat tiller.

Exogenous Hormonal Application Regulates the Occurrence of Wheat Tillers by Changing Endogenous Hormones.

Maximum tiller number and productive tiller number are important traits for wheat grain yield, but research involving the temporal expression of tiller number at different quantitative trait loci (QTL) levels is limited. In the present study, a population set of 371 recombined inbred lines derived from a cross between Chuan-Nong18 and T1208 was used to construct a high-density genetic map using a Wheat55K SNP Array and to perform dynamic QTL analysis of the tiller number at four growth stages. A high-density genetic map containing 11,583 SNP markers and 59 SSR markers that spanned 4,513.95 cM and was distributed across 21 wheat chromosomes was constructed. A total of 28 single environmental QTL were identified in the recombined inbred lines population, and among these, seven QTL were stable and used for multi-environmental and dynamic analysis. These QTL were mapped to chromosomes 2D, 4A, 4D, 5A, 5D, and 7D, respectively. Each QTL explained 1.63-21.22% of the observed phenotypic variation, with an additive effect from -20.51 to 11.59. Dynamic analysis showed that cqTN-2D.2 can be detected at four growth stages of tillering, explaining 4.92-17.16% of the observed phenotypic variations and spanning 13.71 Mb (AX-109283238-AX-110544009: 82189047-95895626) according to the physical location of the flanking markers. The effects of the stable QTL were validated in the recombined inbred lines population, and the beneficial alleles could be utilized in future marker-assisted selection. Several candidate genes for MTN and PTN were predicted. The results provide a better understanding of the QTL selectively expressing the control of tiller number and will facilitate future map-based cloning. 9.17% SNP markers showed best hits to the Chinese Spring contigs. It was indicated that Wheat55K Array was efficient and valid to construct a high-density wheat genetic map.

/pdf/utilization-of-a-wheat55k-snp-array-for-mapping-of-major-qtl-333xcmx8y2.pdf

Utilization of a Wheat55K SNP Array for mapping of major QTL for temporal expression of the tiller number.

SNP-based QTL mapping provided useful information for novel loci that can be used in breeding programs to control tillering and improve yield in wheat via marker-assisted selection.
 Tillering is one of the most important agronomic traits affecting biomass and grain yield potential in wheat. Wheat lines with very limited tillering capacity are more productive than free-tillering lines under severe drought conditions. In this study, three recombinant inbred line (RIL) populations were generated and used, having H461, a low-tillering genotype, as a common parent. A linkage map containing 7808 single nucleotide polymorphism loci was constructed on the basis of H461/CN16 RIL population. Three QTL controlling low tillering were identified on Chromosome (Chr.) 2D (Qltn.sicau-2D), Chr. 2B (Qltn.sicau-2B), and Chr. 5A (Qltn.sicau-5A). Qltn.sicau-2D, Qltn.sicau-2B, and Qltn.sicau-5A explained up to 19.1, 14.6, and 9.6 % of the phenotypic variance, respectively. Comparing with previous findings, Qltn.sicau-2D and Qltn.sicau-2B should thus be novel tillering QTL. The effects of these QTL were further validated in two additional RIL populations. Significant effects of Qltn.sicau-2D were detected across all growth stages in different genetic backgrounds, making it an ideal target for breeding programs as well as for further characterization of the gene(s) underlying this locus.

Identification and validation of novel low-tiller number QTL in common wheat

The invention discloses a molecular marker SSR52 which is closely linked with wheat few-tillering gene Ltn3, wherein the nucleotide sequence of the molecular marker SSR52 is represented as the SEQ ID No.1. Genetic distance between the molecular marker and the wheat few-tillering gene Ltn3 is 0.3 cM. A test result proves that the molecular marker can accurately trace the wheat few-tillering gene and predict tillering characters of wheat, thereby further carrying molecular-designing breeding conveniently. The invention also discloses a method of identifying the molecular marker of the wheat few-tillering gene Ltn3. By means of the method, accuracy of tillering prediction can be increased, success rate of specific plant type breeding can be increased, and achievement of an object of increasing per unit area yield of wheat is accelerated.

Molecular marker SSR52 of wheat few-tillering gene Ltn3 and application thereof

Wheat new few-tillering QTL (quantitative trait locus), primer pair, molecular marker, molecular marking method and application

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Mo Hongjun

Author Tools

Chat about Author

Papers

Identification and validation of novel low-tiller number QTL in common wheat

Molecular marker SSR52 of wheat few-tillering gene Ltn3 and application thereof

Wheat new few-tillering QTL (quantitative trait locus), primer pair, molecular marker, molecular marking method and application