SOME POSSIBLE APPLICATIONS OF MOLECULAR GENETICS IN THE CONSERVATION OF WILD SPECIES FOR CROP IMPROVEMENT

1992 ◽  
pp. 153-181 ◽  
Author(s):  
T. Hodgkin ◽  
D.G. Debouck
Keyword(s):  
Molecular Genetics ◽  
Wild Species ◽  
Crop Improvement

scholarly journals ValSten: a new wild species derived allotetraploid for increasing genetic diversity of the peanut crop (Arachis hypogaea L.)

2021 ◽  
Author(s):  
Dongying Gao ◽  
Ana C. G. Araujo ◽  
Eliza F. M. B. Nascimento ◽  
M. Carolina Chavarro ◽  
Han Xia ◽  
...  
Keyword(s):  
High Resistance ◽  
Wild Species ◽  
Chromosome Doubling ◽  
Crop Improvement ◽  
Snp Array ◽  
Great Majority ◽  
Morphological Variations ◽  
Peanut Crop ◽  
Cultivated Peanut ◽  
Wild Peanut

AbstractIntrogression of desirable traits from wild relatives plays an important role in crop improvement, as wild species have important characters such as high resistance to pests and pathogens. However, use of wild peanut relatives is challenging because almost all wild species are diploid and sexually incompatible with cultivated peanut, which is tetraploid (AABB genome type; 2n = 4x = 40). To overcome the ploidy barrier, we used 2 wild species to make a tetraploid with the same allotetraploid genome composition as cultivated peanut. Crosses were made between 2 diploid wild species, Arachis valida Krapov. and W.C. Greg. (BB genome; 2n = 2x = 20) and Arachis stenosperma Krapov. and W.C. Greg. (AA genome; 2n = 2x = 20). Cuttings from the diploid F1 AB hybrid were treated with colchicine to induce chromosome doubling thus generating an induced allotetraploid. Chromosome counts confirmed polyploidy (AABB genome; 2n = 4x = 40). We named the new allotetraploid ValSten. Plants had well-developed fertile pollen, produced abundant seed and were sexually compatible with cultivated peanut. ValSten exhibits the same high resistance to early and late leaf spot and rust as its diploid parents. Notably, we observed morphological variations, including flower width and branch angles in the earliest generation (S0) of allotetraploids. A SNP array was used to genotype 47 S0 allotetraploids. The great majority of markers showed the additive allelic state from both parents (AABB). However, some loci were AAAA or BBBB, indicating homeologous recombination. ValSten provides a new, vigorous, highly fertile, disease resistant germplasm for peanut research and improvement.

scholarly journals Legacy genetics of Arachis cardenasii in the peanut crop shows the profound benefits of international seed exchange

2021 ◽  
Vol 118 (38) ◽  
pp. e2104899118
Author(s):  
David J. Bertioli ◽  
Josh Clevenger ◽  
Ignacio J. Godoy ◽  
H. T. Stalker ◽  
Shona Wood ◽  
...  
Keyword(s):  
Food Security ◽  
Wild Species ◽  
Biological Diversity ◽  
Crop Improvement ◽  
Economic Benefits ◽  
Convention On Biological Diversity ◽  
Wild Accession ◽  
Seed Exchange ◽  
Peanut Crop ◽  
World Food Security

The narrow genetics of most crops is a fundamental vulnerability to food security. This makes wild crop relatives a strategic resource of genetic diversity that can be used for crop improvement and adaptation to new agricultural challenges. Here, we uncover the contribution of one wild species accession, Arachis cardenasii GKP 10017, to the peanut crop (Arachis hypogaea) that was initiated by complex hybridizations in the 1960s and propagated by international seed exchange. However, until this study, the global scale of the dispersal of genetic contributions from this wild accession had been obscured by the multiple germplasm transfers, breeding cycles, and unrecorded genetic mixing between lineages that had occurred over the years. By genetic analysis and pedigree research, we identified A. cardenasii–enhanced, disease-resistant cultivars in Africa, Asia, Oceania, and the Americas. These cultivars provide widespread improved food security and environmental and economic benefits. This study emphasizes the importance of wild species and collaborative networks of international expertise for crop improvement. However, it also highlights the consequences of the implementation of a patchwork of restrictive national laws and sea changes in attitudes regarding germplasm that followed in the wake of the Convention on Biological Diversity. Today, the botanical collections and multiple seed exchanges which enable benefits such as those revealed by this study are drastically reduced. The research reported here underscores the vital importance of ready access to germplasm in ensuring long-term world food security.

Chickpea genetic resources to enhance production in changing climatic scenario

2015 ◽  
Vol 38 (5) ◽  
Author(s):  
Nidhi Verma ◽  
Surendra Singh ◽  
Yasin Jeshima Khan ◽  
Sushil Kumar ◽  
A K Singh
Keyword(s):  
Genetic Resources ◽  
Wild Species ◽  
Crop Improvement ◽  
Nutritional Composition ◽  
Rapid Changes ◽  
The World ◽  
New Varieties ◽  
Gene Complexes ◽  
Increasing Demand ◽  
Climatic Scenario

Chickpea is one of the dry edible legumes with best nutritional composition as it does not contain any specific major antinutritional or toxic factors. The seeds have an average of 23% protein and 80% of the crops’s nitrogen requirements are met from symbiotic nitrogen fixation. Chickpea has several desirable agronomic characteristics and it is one of the most heat and drought-resistant crop and suitable for production in low moisture and fertility soils. Chickpea remarkably predominates among other pulse crops in terms of both area and production in India. To meet with the ever increasing demand for new varieties with desirable traits, the genetic resources of chickpea are of immense value for the breeders. Due to rapid changes in the agro-ecological conditions throughout the world, the chickpea genetic resources comprising of wild species, old and primitive cultivars, land races endowed with superior gene complexes are being rapidly eroded. Efforts for augmentation of chickpea genetic resources were undertaken by importing the diverse germplasm from various parts of the world. The exotic introduction in chickpea comprises germplasm with resistance to various biotic and abiotic stresses and its wild species for utilisation in crop improvement programmes in India.

Distribution of downy mildew (Bremia lactucaeRegel) resistances in a genebank collection of lettuce and its wild relatives

2011 ◽  
Vol 11 (1) ◽  
pp. 15-25 ◽  
Author(s):  
R. van Treuren ◽  
A. J. M. van der Arend ◽  
J. W. Schut
Keyword(s):  
Downy Mildew ◽  
Wild Species ◽  
Gene Pool ◽  
Crop Improvement ◽  
Northern Asia ◽  
Large Numbers ◽  
Related Wild Species ◽  
Overall Resistance ◽  
Tertiary Gene Pool ◽  
Genebank Collection

Genebanks serve as a rich source of diversity that can be exploited for crop improvement. However, large numbers of accessions usually have to be evaluated to find material with the characters of interest, and therefore, enhanced trait information can facilitate the more efficient selection of accessions by users. In this study, we report on the distribution of resistances to 28 races of downy mildew among 1223 genebank accessions of cultivated lettuce (Lactuca sativaL.) and 14 related wild species. Due to modern plant breeding, the overall level of resistance of cultivars released after 1950 appears to have increased two- to three-fold compared with varieties from earlier periods. Although fully resistant reactions could be observed among the accessions of cultivated lettuce for each of the 28 investigated races, the resistance probability was more than two-fold higher on average for accessions from the wild gene pool. In general, species of the primary gene pool appeared less resistant than those of the secondary or tertiary gene pool. Probabilities for examinedLactucaspecies ranged from 0.29 forL. serriolato 1.00 forL. perenniscompared with 0.19 for cultivated lettuce, with lower overall resistance probabilities observed only forL. altaica,L. dregeanaandL. tenerrima. ForL. serriola, the closest relative of cultivated lettuce and the wild species with the highest number of examined accessions, resistance probabilities to each of the investigated downy mildew races were relatively high for populations originating from Eastern Europe and Northern Asia.

scholarly journals Comparative Studies of Intra and Inter Specific Hybrid of F2 Generations in Mungbean

2020 ◽  
pp. 01-11
Author(s):  
Pandiyan M ◽  
Krishnaveni A ◽  
Sivakumar P ◽  
Vaithiyalingan M ◽  
Jamuna E ◽  
...  
Keyword(s):  
Interspecific Hybridization ◽  
Wild Species ◽  
Interspecific Hybrids ◽  
Crop Improvement ◽  
Interspecific Crosses ◽  
Single Plant ◽  
Plant Yield ◽  
Biotic Stresses ◽  
Vigna Species ◽  
Specific Hybrid

Intra and interspecific hybridization was done for developing donor with respect to MYMV and Bruchids resistance. Several differences in many characters were observed in intra and interspecific hybrids crosses for certain characters. Among all the combination of both intra and interspecific crosses studied, single plant yield increased through only intra specific crosses attempted while resistance to biotic stresses like MYMV and bruchids were improved by interspecific crosses. Hence the utilization of wild species in crop improvement is very effective for donor development compared to intra specific crosses. Keywords: Vigna radiata; Wild Vigna species Intra and Interspecific; Hybridization; Comparative Traits

Evaluation of molecular variability in germplasm of vanilla (Vanilla planifoliaG. Jackson in Andrews) in Southeast Mexico: implications for genetic improvement and conservation

2016 ◽  
Vol 15 (4) ◽  
pp. 310-320 ◽  
Author(s):  
Alma Laura Ramos-Castellá ◽  
Lourdes G. Iglesias-Andreu ◽  
Jaime Martínez-Castillo ◽  
Matilde Ortíz-García ◽  
Rubén Humberto Andueza-Noh ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Wild Species ◽  
Crop Improvement ◽  
Quintana Roo ◽  
Wild Accession ◽  
Vanilla Planifolia ◽  
Molecular Variability ◽  
Assignment Tests ◽  
Sources Of Variation ◽  
Wild Accessions

Molecular variability of vanilla (Vanilla planifolia) and three wild species was assessed to explore the possible sources of variation that can be used for crop improvement. A total of 154 ISSR loci were analysed by the UPGMA, assignment tests of individuals (STRUCTURE) and indices of genetic diversity. The assignment tests were done at two levels: first considering the four species and then only the accessions ofV. planifolia. The molecular analysis indicated 99.3% polymorphism among all species and 70.45% withinV. planifolia. The UPGMA showed the separation of these four species into three groups and groupedV. planifoliaaccessions into three subgroups. The more genetically differentiated accessions were of the Rayada morphotype and a wild accession was from Oaxaca, followed by a wild accession from Quintana Roo; all the commercial accessions ofV. planifolia(Mansa morphotype) were grouped together. The STRUCTURE analysis differentiated betweenV. planifoliaand the three wild species, and among the accessions of the Mansa and Rayada morphotypes and the wild accessions. The STRUCTURE analysis also indicated the presence of mixed individuals. These results are of great importance since the accessions ofV. planifoliathat are genetically more differentiated are the most threatened due to the scarcity of these individuals, the destruction of habitat and replacement by the commercial morphotype. These individuals should be salvaged and used to expand the genetic background of vanilla.

scholarly journals An overview of peanut and its wild relatives

2011 ◽  
Vol 9 (01) ◽  
pp. 134-149 ◽  
Author(s):  
David J. Bertioli ◽  
Guillermo Seijo ◽  
Fabio O. Freitas ◽  
José F. M. Valls ◽  
Soraya C. M. Leal-Bertioli ◽  
...  
Keyword(s):  
Wild Species ◽  
Crop Improvement ◽  
Genomic Analysis ◽  
Linkage Drag ◽  
Root Knot Nematode ◽  
Hybrid Identities ◽  
B Genome ◽  
Cultivated Peanut ◽  
Recent Origin ◽  
The Tropics

The legumeArachis hypogaea, commonly known as peanut or groundnut, is a very important food crop throughout the tropics and sub-tropics. The genus is endemic to South America being mostly associated with the savannah-like Cerrado. All species in the genus are unusual among legumes in that they produce their fruit below the ground. This profoundly influences their biology and natural distributions. The species occur in diverse habitats including grasslands, open patches of forest and even in temporarily flooded areas. Based on a number of criteria, including morphology and sexual compatibilities, the 80 described species are arranged in nine infrageneric taxonomic sections. While most wild species are diploid, cultivated peanut is a tetraploid. It is of recent origin and has an AABB-type genome. The most probable ancestral species areArachis duranensisandArachis ipaënsis, which contributed the A and B genome components, respectively. Although cultivated peanut is tetraploid, genetically it behaves as a diploid, the A and B chromosomes only rarely pairing during meiosis. Although morphologically variable, cultivated peanut has a very narrow genetic base. For some traits, such as disease and pest resistance, this has been a fundamental limitation to crop improvement using only cultivated germplasm. Transfer of some wild resistance genes to cultivated peanut has been achieved, for instance, the gene for resistance to root-knot nematode. However, a wider use of wild species in breeding has been hampered by ploidy and sexual incompatibility barriers, by linkage drag, and historically, by a lack of the tools needed to conveniently confirm hybrid identities and track introgressed chromosomal segments. In recent years, improved knowledge of species relationships has been gained by more detailed cytogenetic studies and molecular phylogenies. This knowledge, together with new tools for genetic and genomic analysis, will help in the more efficient use of peanut's genetic resources in crop improvement.

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