Pyramiding rust

•Download as PPTX, PDF•

1 like•684 views

This study aimed to enhance soybean rust resistance through marker-assisted gene pyramiding of the Rpp2, Rpp3, and Rpp4 genes. Study 1 validated the use of SSR markers linked to each gene for pyramiding. Study 2 evaluated combinations of the genes for resistance. Results showed complementary gene interactions increased resistance, though effectiveness depended on genetic background. Rpp3 conferred more dominant resistance. The study recommends further introgressing gene combinations into elite lines and evaluating durability of resistance.

Enhancing soybean rust resistance through Rpp2,
Rpp3 and Rpp4 pair wise gene pyramiding

M. Maphosa, Talwana, H & Tukamuhabwa, P

Introduction

•Soybean rust is an obligate fungal parasite with multiple
hosts
•It is a polycyclic disease with multiple re-infections

•Genetic resistance is a long term solution

•However, single genes have been overcome in certain
areas whilst others show increasing susceptibility

•To enhance single gene resistance & broaden the base for
available resistance genes

Introduction

•Conventional gene pyramiding is a challenge

•It is not practically feasible in some cases

•Marker assisted gene pyramiding may be a possible solution

•Given that some of the resistance genes have markers
associated with them

•No attempt has be done to use identified SSR for MAS
pyramiding & effect of pyramiding genes

Study 1

•Validate the use of SSR in pyramiding resistance genes Rpp2,
Rpp3 and Rpp4

Study 1

Marker Linkage Group Position1 Resistance Gene Reference
(cM)

Sat_255 J 43.85 Rpp2 Silva et al. (2008)

Satt620 J 53.71 Rpp2 Silva et al. (2008)

Satt460 C2 111.87 Rpp3 Hyten et al. (2009)

Sat263 C2 118.78 Rpp3 Hyten et al. (2009)

Satt288 G 76.77 Rpp4 Yamanaka et al. (2008)

AF162283 G 87.94 Rpp4 Yamanaka et al.(2008)

Study 2

•Evaluating the most effective resistance gene combination
using sporulation & severity indices

Study 2

• All parents has severities higher that the pair wise
combinations
•In the F3 generation

Major Findings

• Complementary gene interactions occurred resulting in
enhanced resistance
• The effectiveness of resistance is influenced by the genetic
background of introgression
• Independent genetic control of severity and sporulation in
soybean rust
• Disproportinate contribution of resistance, Rpp3 more
dominant

Recommendations

• MAS gene pyramiding is feasible

• Introgression to elite lines

• Evalution of pairwise genes in other areas

• Assessing for durability of the resistance

Acknowledgements

•RUFORUM

•International Foundation for Science (4968-1)

•Makerere University Soybean breeding programme

This document discusses marker-assisted selection (MAS), which uses DNA markers linked to target genes or quantitative trait loci (QTLs) to assist plant breeding. The key points are: 1. Markers must be tightly linked (less than 5 cM) to the target loci to be reliable indicators for selection. Using flanking markers improves reliability. 2. Markers must also be polymorphic between parental lines to differentiate parental genomes. 3. The general steps in MAS are selecting parents, developing breeding populations, isolating DNA, scoring markers, and correlating markers with traits. 4. MAS accelerates backcrossing by allowing selection based on background markers rather than visual inspection

Back and test cross

Pravin Cholke

1. A back cross is a cross between an F1 individual and one of its parents. A test cross is specifically a cross between an F1 individual and its homozygous recessive parent. 2. Back crosses and test crosses are important for determining genotypes, obtaining pure lines, and introducing desirable traits through successive crosses. 3. A test cross, unlike a general back cross, will result in a 1:1 ratio of dominant to recessive phenotypes in the F2 generation, allowing determination of genetic constitution.

Presentation on Backcross Method of Breeding

Dr. Kaushik Kumar Panigrahi

This document discusses the backcross breeding method. It defines key terms like recurrent parent and donor parent. It explains that backcrossing is used to transfer traits from a donor parent to a recurrent parent while recovering the genotype of the recurrent parent. Over 5-7 backcrosses are typically done. The procedure differs depending on whether the gene being transferred is dominant or recessive. Backcrossing has been used successfully to develop disease resistance in many crops. It allows for trait transfer between related species.

Adaptive_introgression_Adriana_June

Adriana Suarez-Gonzalez

This study analyzed introgression from P. balsamifera into P. trichocarpa and found evidence that introgressed regions may provide adaptations. Three introgressed regions were identified on chromosomes 6, 12, and 15. The region on chromosome 15 showed enrichment for genes involved in development and signals of balancing selection, suggesting adaptive introgression. Introgressed alleles in this region were associated with higher chlorophyll content in P. trichocarpa, which could confer faster growth. Further genome-wide and phenotypic analyses are needed to better understand the adaptive effects of introgression.

Perspectives on Applied Aspects of Breeding for Rust Resistance

Borlaug Global Rust Initiative

This document summarizes a panel discussion on breeding wheat for rust resistance. The panelists discussed challenges such as under-resourced breeding programs and complex traits. Core traits for CIMMYT wheats were identified as high yield, rust resistance, drought tolerance, and quality. Additional traits were listed for specific environments. Progress was reported in identifying rust resistance genes and developing lines with improved yield potential through international shuttle breeding between Mexico and Kenya. The importance of integrating diverse resistance genes and quantitative resistance for durability was emphasized.

GP120 pdf

Jordan Ashworth

This document summarizes research analyzing changes in the stability of the HIV-1 envelope protein gp120 during infection within two patients. Gp120 sequences were extracted from samples taken at multiple time points from each patient and analyzed evolutionarily. For one patient sampled over 212 days, gp120 stability decreased over time as mutations accumulated. Most mutations had a neutral effect on stability early in infection, but later mutations were more common in gp120's outer domain and decreased stability. This pattern was not seen in the other patient only sampled over 30 days. The decreasing stability over time raises questions about how this impacts HIV-1 fitness and host immune evasion.

Backcross method for dominant and recessive gene transfer.

Pawan Nagar

This document discusses the backcross method for transferring dominant and recessive genes. The backcross method involves using a recurrent parent that lacks a desired trait and a donor parent that has the trait in order to transfer the trait to the recurrent parent over multiple generations. For dominant traits, backcrosses can be done sequentially, while for recessive traits, F2 generations must be grown after the first and subsequent backcrosses to identify plants with the recessive trait. The backcross method allows a trait to be transferred without significantly changing the genotype of the recurrent parent. Some examples of traits transferred through backcrossing include rust resistance in wheat and downy mildew resistance in pearl millet.

Nikhil ahlawat

Sardar Vallabhbhai Patel University of Agriculture and Technology Meerut 250110

This document provides an overview of quantitative trait locus (QTL) mapping. It discusses what a QTL is, the types of mapping populations used in QTL mapping like recombinant inbred lines (RILs) and near isogenic lines (NILs), and statistical methods for QTL mapping including single marker analysis, interval mapping, and composite interval mapping. The document also covers factors that affect the power of QTL mapping and limitations of QTL mapping like low resolution and small effects of individual QTLs.

This document summarizes information about CircoFLEX, a PCV2 vaccine produced by Boehringer Ingelheim using their PCA TM and Impran FLEX TM technologies. It discusses results from trials showing CircoFLEX was effective at reducing mortality and increasing weight gain when given to pigs at 21 and 42 days of age. It also summarizes results from multiple trials and field studies demonstrating the benefits of CircoFLEX compared to other PCV2 vaccines when given as a single dose at 3 weeks of age.

Chiranjeev patel thesis viva voce

Sardar Vallabhbhai Patel University of Agriculture and Technology Meerut 250110

Topic- Genetic Variability and Stability Analysis in Greengram [Vigna radiata (L.) Wilczek] PRESENTED BY CHIRANJEEV Id. No. – 4213, M. Sc. (Ag.) In the presence of External examiner and Members of Advisory Committee Venue: Seminar class room On date: 27/10/2020 DEPARTMENT OF GENETICS AND PLANT BREEDING SARDAR VALLABHBHAI PATEL UNIVERSITY OF AGRICULTURE AND TECHNOLOGY MEERUT-250110 (U.P.) India

Tilling, Eco- Tilling and MAS for crop improvement

Dr. Shobha D. Surbhaiyya

wheat association mapping LTN

Senthil Natesan

This document summarizes a study that used genome wide association mapping (GWAS) and genomic selection (GS) to identify genetic markers linked to leaf tip necrosis (LTN) in wheat. GWAS identified markers linked to known LTN genes Lr34, Lr46, and Lr68, as well as novel loci on chromosomes 2BL, 3BS, 5BL and 7BS. Genomic selection models were able to accurately predict LTN, with the G-BLUP model achieving the highest prediction accuracy. The study demonstrated the utility of genotyping by sequencing (GBS) markers, GWAS and GS for dissecting complex traits in wheat breeding.

Peptide nucleic acid restores colistin susceptibility through modulation of M...

MarianaJaramilloGmez

1 gpb 621 quantitative genetics introduction

SaravananK153

This document provides an introduction to principles of quantitative genetics. It discusses the history and development of the field, beginning with Mendel's foundational work in genetics and Galton's development of statistical techniques. It describes how early geneticists differed in their views of inheritance as qualitative vs quantitative. Key figures who helped establish quantitative genetics are mentioned, including Fisher who integrated Mendelian and statistical approaches. The document outlines differences between Mendelian and polygenic traits. It also discusses types of statistics used in quantitative genetics like first and second degree statistics, as well as biometrical techniques and parameters used in plant breeding like assessment of variability, selection of elite genotypes, choice of parents, and stability analysis.

Prof dev needs

Pyramiding rust

Recommended

Recommended

More Related Content

What's hot

What's hot (6)

More from RUFORUM

More from RUFORUM (20)

Pyramiding rust