scholarly journals Plant genetic resources management and pre-breeding in genomics era

2019 ◽  
Vol 79 (01S) ◽  
Author(s):  
Kuldeep Singh ◽  
Sandeep Kumar ◽  
S. Raj Kumar ◽  
Mohar Singh ◽  
Kavita Gupta

Plant Genetic Resources (PGR) conserved in gene bank provides genetic variability for efficient utilization in breeding programmes. Pre-breeding is required for broadening the genetic base of the crop through identification of useful traits in un-adapted materials and transfer them into better adapted ones for further breeding. So, pre-breeding is a promising alternative (due to use of un-adapted materials) to link genetic resources and breeding programs. Utilization of PGR in crop improvement programmes including prebreeding have been very limited. Advances in genomics have provided us with high-quality reference genomes, sequencing and re-sequencing platforms with reduced cost, marker and QTL assisted selection, genomic selection and population level genotyping platforms. Further, genome editing tools like, CRISPR/Cas9 and its latest modification base editing technology can be used to generate target specific mutants and are important for establishing gene functions with respect to their phenotypes through developing knockout mutations. These new genomic tools can be used to generate, analyse and manipulate the genetic variability for designing cultivars with the desired traits. The genomic tools has not only accelerated the utilization of PGR but also assisted pre-breeding through rapid selection of trait-specific germplasm, reduced periods in breeding cycle for confirming gene of interest in intermediate material and validation of transfer of gene of interest in the cultivated gene pool. In crops, where limited genetic and genomic resources are available, pre-breeding becomes very challenging. We can say that genomics assisted utilization of PGR and prebreeding has accelerated the pace of introgression of complex traits in different crop cultivars.and yield plateau has already been achieved in these cultivars (Chen et al. 2014a). Under these circumstances, use of Plant Genetic Resources (PGR) in crop improvement programs provides an avenue to solve the problem.

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 511A-511
Author(s):  
Peter Bretting

Plants provide humans with food, fiber, feed, ornamentals, industrial products, medicine, shelter, and fuel. As vegetation, they maintain global environmental integrity and the carrying capacity for all life. From an anthropocentric perspective, plants serve as genetic resources (PGR) for sustaining the growing human population. Research on PGR can provide basic knowledge for crop improvement or environmental management that enables renewable, sustainable production of the preceding necessities. PGR also provide the raw material for increasing yield and end product's quality, while requiring fewer inputs (water, nutrients, agrichemicals, etc.). The staples of life—30 or so major grain, oilseed, fiber, and timber species—comprise the “thin green line” vital to human survival, either directly, or through trade and income generation. Many crop genebanks worldwide focus on conserving germplasm of these staples as a shield against genetic vulnerability that may endanger economies and humanity on an international scale. Fewer genebanks and crop improvement programs conserve and develop “minor crops,” so called because of their lesser economic value or restricted cultivation globally. Yet, these minor crops, many categorized as horticultural, may be key to human carrying capacity—especially in geographically or economically marginal zones. The USDA/ARS National Plant Germplasm System (NPGS) contains a great number and diversity of minor crop germplasm. The NPGS, other genebanks, and minor crop breeding programs scattered throughout the world, help safeguard human global carrying capacity by providing the raw genetic material and genetic improvement infrastructure requisite for producing superior minor crops. The latter may represent the best hope for developing new varieties and crops, new crop rotations, and new renewable products that in the future may enhance producer profitability or even ensure producer and consumer survival.


Author(s):  
Pallavi Sinha ◽  
Vikas K. Singh ◽  
Abhishek Bohra ◽  
Arvind Kumar ◽  
Jochen C. Reif ◽  
...  

Abstract Key message Integrating genomics technologies and breeding methods to tweak core parameters of the breeder’s equation could accelerate delivery of climate-resilient and nutrient rich crops for future food security. Abstract Accelerating genetic gain in crop improvement programs with respect to climate resilience and nutrition traits, and the realization of the improved gain in farmers’ fields require integration of several approaches. This article focuses on innovative approaches to address core components of the breeder’s equation. A prerequisite to enhancing genetic variance (σ2g) is the identification or creation of favorable alleles/haplotypes and their deployment for improving key traits. Novel alleles for new and existing target traits need to be accessed and added to the breeding population while maintaining genetic diversity. Selection intensity (i) in the breeding program can be improved by testing a larger population size, enabled by the statistical designs with minimal replications and high-throughput phenotyping. Selection priorities and criteria to select appropriate portion of the population too assume an important role. The most important component of breeder′s equation is heritability (h2). Heritability estimates depend on several factors including the size and the type of population and the statistical methods. The present article starts with a brief discussion on the potential ways to enhance σ2g in the population. We highlight statistical methods and experimental designs that could improve trait heritability estimation. We also offer a perspective on reducing the breeding cycle time (t), which could be achieved through the selection of appropriate parents, optimizing the breeding scheme, rapid fixation of target alleles, and combining speed breeding with breeding programs to optimize trials for release. Finally, we summarize knowledge from multiple disciplines for enhancing genetic gains for climate resilience and nutritional traits.


Crop Science ◽  
2019 ◽  
Vol 59 (3) ◽  
pp. 853-857 ◽  
Author(s):  
Gayle M. Volk ◽  
Deana Namuth-Covert ◽  
Patrick F. Byrne

2004 ◽  
Vol 2 (1) ◽  
pp. 3-21 ◽  
Author(s):  
B. I. G. Haussmann ◽  
H. K. Parzies ◽  
T. Presterl ◽  
Z. Su?i? ◽  
T. Miedaner

2010 ◽  
Vol 8 (2) ◽  
pp. 171-181 ◽  
Author(s):  
C. C. M. van de Wiel ◽  
T. Sretenović Rajičić ◽  
R. van Treuren ◽  
K. J. Dehmer ◽  
C. G. van der Linden ◽  
...  

Genetic variation in Lactuca serriola, the closest wild relative of cultivated lettuce, was studied across Europe from the Czech Republic to the United Kingdom, using three molecular marker systems, simple sequence repeat (SSR, microsatellites), AFLP and nucleotide-binding site (NBS) profiling. The ‘functional’ marker system NBS profiling, targeting disease resistance genes of the NBS/LRR family, did not show marked differences in genetic diversity parameters to the other systems. The autogamy of the species resulted in low observed heterozygosity and high population differentiation. Intra-population variation ranged from complete homogeneity to nearly complete heterogeneity. The highest genetic diversity was found in central Europe. The SSR results were compared to SSR variation screened earlier in the lettuce collection of the Centre for Genetic Resources, the Netherlands (CGN). In the UK, practically only a single SSR genotype was found. This genotype together with a few other common SSR genotypes comprised a large part of the plants sampled on the continent. Among the ten most frequent SSR genotypes observed, eight were already present in the CGN collection. Overall, the CGN collection appears to already have a fair representation of genetic variation from NW Europe. The results are discussed in relation to sampling strategies for improving genebank collections of crop wild relatives.


1983 ◽  
Vol 63 (1) ◽  
pp. 11-21 ◽  
Author(s):  
JOHN D. MAHON

The possibility that breeding programs may be reaching a point of limited progress because of the lack of genetic diversity has often been raised. However, there is also an often-expressed feeling that considerable genetic variability may exist in fundamental physiological processes. In this review, an attempt is made to examine whether there is evidence of genetic variability in quantitative physiological characters, and if so, whether such variability is likely to be useful to crop improvement programs. The results, presented from the literature and the author’s laboratory, indicate that physiological characters demonstrate considerable genotypic variability in expression. Moreover, in cases where genotype performance has been studied over a range of environments or where crossing studies have been carried out, physiological characters often have relatively high heritabilities. This suggests that, at least from a genetic standpoint, improvements in the expression of physiological processes may be possible. On the other hand, the problems of environmental sensitivity and its resultant error variability, combined with cumbersome methodology and complex physiological interactions, make it difficult to relate individual physiological characters to agronomic benefits, and make large genetic studies difficult. The exploitation of physiological diversity remains a major challenge to plant scientists.Key words: Genetic heritability, physiology of yield


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1634
Author(s):  
Atiqullah Khaliqi ◽  
Mohd Y. Rafii ◽  
Norida Mazlan ◽  
Mashitah Jusoh ◽  
Yusuff Oladosu

The knowledge of genetic variability and breeding techniques is crucial in crop improvement programs. This information is especially important in underutilized crops such as Bambara groundnut, which have limited breeding systems and genetic diversity information. Hence, this study evaluated the genetic variability and established the relationship between the yield and its components in Bambara groundnut based on seed weight using multivariate analysis. A field trial was conducted in a randomized complete block design with three replications on 28 lines. Data were collected on 12 agro-morphological traits, and a statistical analysis was conducted using SAS version 9.4 software, while the variance component, genotypic and phenotypic coefficient variation, heritability, and genetic advance values were estimated. A cluster analysis was performed using NT-SYS software to estimate the genetic relations among the accessions. The results showed significant variability among the accessions based on the yield and yield component characteristics. The evaluated lines were grouped into seven primary clusters based on the assessed traits using the UPGMA dendrogram. Based on the overall results, G5LR1P3, G1LR1P3, G4LR1P1, G2SR1P1 and G3SR1P4 performed the best for the yield and yield components. These improved lines are recommended for large-scale evaluation and utilization in future breeding programs to develop high-yield Bambara groundnut varieties.


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