scholarly journals Current Perspectives on Introgression Breeding in Food Legumes

2021 ◽  
Vol 11 ◽  
Author(s):  
Aditya Pratap ◽  
Arpita Das ◽  
Shiv Kumar ◽  
Sanjeev Gupta
Keyword(s):  
Genetic Variation ◽  
Gene Transfer ◽  
Agronomic Traits ◽  
Practical Importance ◽  
Crop Wild Relatives ◽  
Linkage Drag ◽  
Distant Hybridization ◽  
Introgression Breeding ◽  
Genetic Base ◽  
Food Legumes

Food legumes are important for defeating malnutrition and sustaining agri-food systems globally. Breeding efforts in legume crops have been largely confined to the exploitation of genetic variation available within the primary genepool, resulting in narrow genetic base. Introgression as a breeding scheme has been remarkably successful for an array of inheritance and molecular studies in food legumes. Crop wild relatives (CWRs), landraces, and exotic germplasm offer great potential for introgression of novel variation not only to widen the genetic base of the elite genepool for continuous incremental gains over breeding cycles but also to discover the cryptic genetic variation hitherto unexpressed. CWRs also harbor positive quantitative trait loci (QTLs) for improving agronomic traits. However, for transferring polygenic traits, “specialized population concept” has been advocated for transferring QTLs from CWR into elite backgrounds. Recently, introgression breeding has been successful in developing improved cultivars in chickpea (Cicer arietinum), pigeonpea (Cajanus cajan), peanut (Arachis hypogaea), lentil (Lens culinaris), mungbean (Vigna radiata), urdbean (Vigna mungo), and common bean (Phaseolus vulgaris). Successful examples indicated that the usable genetic variation could be exploited by unleashing new gene recombination and hidden variability even in late filial generations. In mungbean alone, distant hybridization has been deployed to develop seven improved commercial cultivars, whereas in urdbean, three such cultivars have been reported. Similarly, in chickpea, three superior cultivars have been developed from crosses between C. arietinum and Cicer reticulatum. Pigeonpea has benefited the most where different cytoplasmic male sterility genes have been transferred from CWRs, whereas a number of disease-resistant germplasm have also been developed in Phaseolus. As vertical gene transfer has resulted in most of the useful gene introgressions of practical importance in food legumes, the horizontal gene transfer through transgenic technology, somatic hybridization, and, more recently, intragenesis also offer promise. The gains through introgression breeding are significant and underline the need of bringing it in the purview of mainstream breeding while deploying tools and techniques to increase the recombination rate in wide crosses and reduce the linkage drag. The resurgence of interest in introgression breeding needs to be capitalized for development of commercial food legume cultivars.

Widening the genetic base of cultivated lentil through hybridization of Lens culinaris ‘Eston’ and L. ervoides accession IG 72815

2013 ◽  
Vol 93 (6) ◽  
pp. 1037-1047 ◽  
Author(s):  
A. Tullu ◽  
K. Bett ◽  
S. Banniza ◽  
S. Vail ◽  
A. Vandenberg
Keyword(s):  
Genetic Variation ◽  
Disease Resistance ◽  
Seed Weight ◽  
Lens Culinaris ◽  
Agronomic Traits ◽  
Breeding Programs ◽  
Genetic Base ◽  
Recessive Genes ◽  
Cultivated Species ◽  
Transgressive Segregations

Tullu, A., Bett, K., Banniza, S., Vail, S. and Vandenberg, A. 2013. Widening the genetic base of cultivated lentil through hybridization of Lens culinaris ‘Eston’ and L . ervoides accession IG 72815. Can. J. Plant Sci. 93: 1037–1047. Lentil (Lens culinaris Medik.) is affected by many stresses and the genetic variation for resistance to some of these stresses is limited in the cultivated germplasm. Introgression of genes from diverse sources for the improvement of disease resistance and agronomic performance is urgently needed. An interspecific recombinant inbred line (RIL) population designated LR-26 was developed from a cross of L. culinaris ‘Eston’ and L. ervoides (Brign.) Grande accession IG 72815. RILs were phenotyped (1) to examine the inheritance of resistance to the more aggressive race 0 of Colletotrichum truncatum (Schwein.) Andus & W.D. Moore, causal agent of anthracnose, for which resistance is lacking in the cultivated species and (2) to study the genetic variation in agronomic traits and their relationships to each other. Greenhouse studies were conducted to screen for resistance to race 0 of C. truncatum and evaluate RILs for variations of agronomic characters. Two recessive genes conferred resistance in L. ervoides accession IG 72815. Traits varied significantly and showed transgressive segregations. Seed yield had a significant and positive relationship with biomass, straw yield, seed weight and harvest index. About 20 lines that performed better than Eston in terms of podding ability, lodging, and stand at maturity can be used in a breeding program. LR-26-180 had an 8% greater seed weight than Eston, suggesting that IG 72815 has alleles contributing positively to seed size. Overall, results show that IG 72815 can be used in breeding programs to improve disease resistance and quantitative traits of lentil.

Inheritance of Some Morphological Characteristics of Parental Lines in Mustard-Rape Hybrid

2020 ◽  
pp. 23-30
Keyword(s):  
First Generation ◽  
Agronomic Traits ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Hybrid Plant ◽  
Distant Hybridization ◽  
Degree Of Dominance ◽  
Whole Plant ◽  
Row Width ◽  
The Difference

Distant hybridization is known to play an important role in expanding the gene pool of any crop. It is believed that the combination of different genomes in one nucleus, as a rule, is accompanied by the phenomenon of “genomic shock”, resulting in a variety of genetic and epigenetic changes. This provides a wealth of material for the selection of genotypes adapted to different environmental conditions. Interspecific hybrids in different combinations were obtained in the genus Brassica, however, until now, interest in distant hybridization in this genus has not died out, since such important crops as rapeseed and mustard demand an improvement of many important agronomic traits. The aim of this work was to study the degree of manifestation of morphological characters of a leaf, flower, and plant as a whole in the hybrid obtained by crossing of brown mustard of the variety Slavyanka and a collection specimen of spring rape. Seeds were sown in the spring of 2019 in a field with 30 cm row width. During the flowering period a number of morphological characters of a flower, leaf, and the whole plant were analyzed. Each parameter was evaluated with 10 plants. The degree of dominance in first-generation hybrid was calculated by the formula of Beil, Atkins (1965). The dominance coefficients were not determined in the case when the difference between the parental samples was insignificant. Differences between parental samples were determined by Student t-test. The level of heterosis was calculated according to the formula of Rasul et al (2002). In a mustard-rapeseed hybrid, the size of the leaves of the lower row was inherited by the type of rapeseed, which had larger leaves than mustard. The height of the hybrid plant was inherited by the type of mustard (hp = 1.32, Ht = 4.89%), and intermediate inheritance was observed for the length of the internodes (hp = -0.48). The size of the flower petals and sepals was inherited by the type of rapeseed, and significant heterosis was observed for the length of the pistil (Ht = 33.57%). The data obtained are of interest for understanding the interaction of genes of different genomes in the genus Brassica.

Genetic Variation Affecting Agronomic Traits in Sugarcane in Response to High and Low Phosphorus Availability

2014 ◽  
Vol 106 (6) ◽  
pp. 2296-2304 ◽  
Author(s):  
Gustavo da Silveira ◽  
Paulo M. de A. Costa ◽  
Volmir Kist ◽  
Cleverson de F. Almeida ◽  
David Carlos F. Baffa ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Agronomic Traits ◽  
Phosphorus Availability ◽  
Low Phosphorus

scholarly journals Canaryseed (Phalaris canariensis L.) accessions from nineteen countries show useful genetic variation for agronomic traits

2011 ◽  
Vol 91 (1) ◽  
pp. 37-48 ◽  
Author(s):  
M. Cogliatti ◽  
F. Bongiorno ◽  
H. Dalla Valle ◽  
W J Rogers
Keyword(s):  
Genetic Variation ◽  
Grain Yield ◽  
Harvest Index ◽  
Agronomic Traits ◽  
Grain Weight ◽  
Environment Interaction ◽  
Grain Number ◽  
Harvest Maturity ◽  
Phalaris Canariensis ◽  
Late Sowing

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype × environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets.Key words: Phalaris canariensis, canaryseed, accessions, yield, phenology, genetics, breeding

scholarly journals Evaluating the genetic variability of rubber hybrid progenies of the two crosses PB260 x RO44/71 and PB260 x RO62/54 by RAPD technique

2019 ◽  
Vol 2 (3) ◽  
pp. 36-43
Author(s):  
Thien Minh Nguyen ◽  
Tien Thi My Pham
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Genetic Similarity ◽  
Field Experiments ◽  
Agronomic Traits ◽  
Genetic Relationships ◽  
Genetic Material ◽  
Population Based ◽  
Shannon Index ◽  
Polymorphic Bands

The agronomic values of this population have been evaluated in the field experiments based on their phenotypic performance of agronomic traits, but the genetic variability of this population needs to be evaluated via techniques based on genetic material - DNA. In this study, the genetic variability in the investigated population of 71 hybrids and their parents was evaluated by RAPD technique, using eight selected arbitrarily primers; Genetic parameters and dendrogram expressing the genetic relationships among the investigated population were analyzed by GenALEx 6.1, Popgene 1.31 and NTSYSpc 2.1 softwares. Eight primers were used to generate the amplify products on each individual in the investigated population. From 74 genotypes, a total of 109 fragments were generated, among which, there were 89 polymorphic bands representing 81.65% with an average of 11 polymorphic bands/primer. Genetic similarity coefficient among the investigated population, based on DICE coefficient, ranged from 0.560 (LH05/0822 and PB260) to 0.991 (LH05/0781 and LH05/0841) with an average of 0,796, meaning that the genetic distance among ranged from 0.009 to 0.440 with an average of 0.231. The Shannon index and mean heterozygosity values were 0.328 and 0,176, respectively. This indicated that the progenies of the two investigated crosses possessed a relatively high range of genetic variability. The analysis of molecular variance (AMOVA) showed that genetic variation within population represented 62%, while genetic variation among two different crosses contributes 38% to the total genetic variability. Dendrogram based on DICE’s genetic similarity using UPGMA method showed that the hybrids divide into two major genetic groups (0.75), but the crosses were scattered independently of the hybrid.

scholarly journals RECAS9: Recombining wild species introgression via mitotic gene editing in barley

2020 ◽  
Author(s):  
Shelly Lazar ◽  
Manas Ranjan Prusty ◽  
Khaled Bishara ◽  
Amir Sherman ◽  
Eyal Fridman
Keyword(s):  
Wild Species ◽  
Association Studies ◽  
Digital Pcr ◽  
Crop Wild Relatives ◽  
Linkage Drag ◽  
Genome Wide Association Studies ◽  
Starting Point ◽  
Rnp Complex ◽  
Causal Genes ◽  
The Individual

AbstractGenetic loci underlying variation in traits with agronomic importance or genetic risk factors in human diseases have been identified by linkage analysis and genome-wide association studies. However, narrowing down the mapping to the individual causal genes and variations within these is much more challenging, and so is the ability to break linkage drag between beneficial and unfavourable loci in crop breeding. We developed RECAS9 as a transgene-free approach for precisely targeting recombination events by delivering CRISPR/Cas9 ribonucleotide protein (RNP) complex into heterozygous mitotic cells for the barley (Hordeum vulgare) Heat3.1 locus. A wild species (H. spontaneum) introgression in this region carries the agronomical unfavourable tough rachis phenotype (non-brittle) allele linked with a circadian clock accelerating QTL near GIGANTEA gene. We delivered RNP, which was targeted between two single nucleotide polymorphism (SNPs), to mitotic calli cells by particle bombardment. We estimated recombination events by next generation sequencing (NGS) and droplet digital PCR (ddPCR). While NGS analysis grieved from confounding effects of PCR recombination, ddPCR analysis allowed us to associate RNP treatment on heterozygous individuals with significant increase of homologous directed repair (HDR) between cultivated and wild alleles, with recombination rate ranging between zero to 57%. These results show for the first time in plants a directed and transgene free mitotic recombination driven by Cas9 RNP, and provide a starting point for precise breeding and fine scale mapping of beneficial alleles from crop wild relatives.

scholarly journals Localized Hypermutation is the Major Driver of Meningococcal Genetic Variability during Persistent Asymptomatic Carriage

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Luke R. Green ◽  
Ali A. Al-Rubaiawi ◽  
Mohammad A. R. M. Al-Maeni ◽  
Odile B. Harrison ◽  
Matthew Blades ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Gene Transfer ◽  
Outer Membrane ◽  
Antigenic Variation ◽  
Allelic Variation ◽  
Host Responses ◽  
Content Type ◽  
Type Iv ◽  
Asymptomatic Carriage ◽  
Genes Encoding

ABSTRACT Host persistence of bacteria is facilitated by mutational and recombinatorial processes that counteract loss of genetic variation during transmission and selection from evolving host responses. Genetic variation was investigated during persistent asymptomatic carriage of Neisseria meningitidis. Interrogation of whole-genome sequences for paired isolates from 25 carriers showed that de novo mutations were infrequent, while horizontal gene transfer occurred in 16% of carriers. Examination of multiple isolates per time point enabled separation of sporadic and transient allelic variation from directional variation. A comprehensive comparative analysis of directional allelic variation with hypermutation of simple sequence repeats and hyperrecombination of class 1 type IV pilus genes detected an average of seven events per carrier and 2:1 bias for changes due to localized hypermutation. Directional genetic variation was focused on the outer membrane with 69% of events occurring in genes encoding enzymatic modifiers of surface structures or outer membrane proteins. Multiple carriers exhibited directional and opposed switching of allelic variants of the surface-located Opa proteins that enables continuous expression of these adhesins alongside antigenic variation. A trend for switching from PilC1 to PilC2 expression was detected, indicating selection for specific alterations in the activities of the type IV pilus, whereas phase variation of restriction modification (RM) systems, as well as associated phasevarions, was infrequent. We conclude that asymptomatic meningococcal carriage on mucosal surfaces is facilitated by frequent localized hypermutation and horizontal gene transfer affecting genes encoding surface modifiers such that optimization of adhesive functions occurs alongside escape of immune responses by antigenic variation. IMPORTANCE Many bacterial pathogens coexist with host organisms, rarely causing disease while adapting to host responses. Neisseria meningitidis, a major cause of meningitis and septicemia, is a frequent persistent colonizer of asymptomatic teenagers/young adults. To assess how genetic variation contributes to host persistence, whole-genome sequencing and hypermutable sequence analyses were performed on multiple isolates obtained from students naturally colonized with meningococci. High frequencies of gene transfer were observed, occurring in 16% of carriers and affecting 51% of all nonhypermutable variable genes. Comparative analyses showed that hypermutable sequences were the major mechanism of variation, causing 2-fold more changes in gene function than other mechanisms. Genetic variation was focused on genes affecting the outer membrane, with directional changes in proteins responsible for bacterial adhesion to host surfaces. This comprehensive examination of genetic plasticity in individual hosts provides a significant new platform for rationale design of approaches to prevent the spread of this pathogen.

scholarly journals Capturing genetic variation in crop wild relatives: An evolutionary approach

2018 ◽  
Vol 11 (8) ◽  
pp. 1293-1304 ◽  
Author(s):  
Paul A. Egan ◽  
Anne Muola ◽  
Johan A. Stenberg
Keyword(s):  
Genetic Variation ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Evolutionary Approach
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