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 ◽  
...  

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.

2021 ◽  
Vol 118 (38) ◽  
pp. e2104899118
Author(s):  
David J. Bertioli ◽  
Josh Clevenger ◽  
Ignacio J. Godoy ◽  
H. T. Stalker ◽  
Shona Wood ◽  
...  

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.


Author(s):  
Dongying Gao ◽  
Ana C. G. Araujo ◽  
Eliza F. M. B. Nascimento ◽  
M. Carolina Chavarro ◽  
Han Xia ◽  
...  

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.


2021 ◽  
Author(s):  
Varun Hiremath ◽  
Kanwar Pal Singh ◽  
Neelu Jain ◽  
Kishan Swaroop ◽  
Pradeep Kumar Jain ◽  
...  

Abstract Genetic diversity and structure analysis using molecular markers is necessary for efficient utilization and sustainable management of gladiolus germplasm. Genetic analysis of gladiolus germplasm using SSR markers is largely missing due to scarce genomic information. In the present investigation, we report 66.66% cross transferability of Gladiolus palustris SSRs whereas 48% of Iris EST-SSRs were cross transferable across the gladiolus genotypes used in the study. A total of 17 highly polymorphic SSRs revealed a total 58 polymorphic loci ranging from two to six in each locus with an average of 3.41 alleles per marker. PIC values ranged from 0.11 to 0.71 with an average value of 0.48. Four SSRs were selectively neutral based on Ewens-Watterson test. Analysis of genetic structure of 84 gladiolus genotypes divided whole germplasm into two subpopulations. 35 genotypes were assigned to subpopulation 1 whereas 37 to subpopulation 2 and rest of the genotypes recorded as admixture. Analysis of molecular variance indicated maximum variance (53.59%) among individuals within subpopulations whereas 36.55% of variation observed among individuals within total population. Least variation (9.86%) was noticed between two subpopulations. Moderate (FST = 0.10) genetic differentiation of two subpopulations was observed. Grouping pattern of population structure was consistent with UPGMA dendrogram based on simple matching dissimilarity coefficient (ranged from 01.6 to 0.89) and PCoA. Genetic relationships assessed among the genotypes of respective clusters assist the breeders in selecting desirable parents for crossing. SSR markers from present study can be utilized for cultivar identification, conservation and sustainable utilization of gladiolus genotypes for crop improvement.


2018 ◽  
Vol 53 (3) ◽  
pp. 307-315
Author(s):  
André Ricardo Zeist ◽  
Juliano Tadeu Vilela de Resende ◽  
Marcos Ventura Faria ◽  
André Gabriel ◽  
Israel Felipe Lustosa da Silva ◽  
...  

Abstract: The objective of this work was to estimate the base temperature for node emission and plastochron determination in wild species of tomato, in the Redenção cultivar, and in their respective interspecific F1 hybrids. The wild accessions Solanum pimpinellifolium AF 26970, Solanum galapagense LA-1401, Solanum peruvianum AF 19684, Solanum habrochaites var. hirsutum PI-127826, Solanum habrochaites var. glabratum PI-134417, and Solanum pennellii LA-716; the cultivar Redenção (Solanum lycopersicum); and their respective interspecific hybrids were evaluated, on the transplanting dates 12/22/2015, 2/12/2016, and 4/6/2016. The base temperature was estimated using the least mean squared error of the linear regression between the number of nodes and the accumulated thermal sum. The plastochron for the main stem and the first three lateral stems was estimated using the base temperature. The base temperature for node emission and plastochron determination varied from 4.5 to 14.8°C. The species S. habrochaites var. hirsutum accession PI-127826, S. habrochaites var. glabratum accession PI-134417, and their hybrids with the Redenção cultivar showed the lowest base temperatures and plastochron for the main stem, whereas the remaining wild species and interspecific hybrids had a base temperature near that of cultivated tomato. Wild species and interspecific hybrids of tomato show a great variation in base temperature for node emission and plastochron determination.


Author(s):  
Nathaniel Schleif ◽  
Shawn M. Kaeppler ◽  
Heidi F. Kaeppler

AbstractPlant breeding relies on the presence of genetic variation, which is generated by a random process of mutagenesis that acts on existing gene pools. This variation is then recombined into new forms at frequencies impacted by the local euchromatin and heterochromatin environment. The result is a genetic lottery where plant breeders face increasingly low odds of generating a “winning” plant genotype. Genome editing tools enable targeted manipulation of the genome, providing a means to increase genetic variation and enhancing the chances for plant breeding success. Editing can be applied in a targeted way, where known genetic variation that improves performance can be directly brought into lines of interest through either deletion or insertion. This empowers approaches that are traditionally difficult such as novel domestication and introgression of wild accessions into a germplasm pool. Furthermore, broader editing-mediated approaches such as recombination enhancement and targeted random mutagenesis bring novel ways of variation creation to the plant breeding toolbox. Continued development and application of plant genome editing tools will be needed to aid in meeting critical global crop improvement needs.


2021 ◽  
Vol 16 (4) ◽  
pp. 10-14
Author(s):  
Sergey Bobkov ◽  
Ivan Bychkov

The objective consisted in study of wild pea representatives on chlorophyll and carotenoid content for use in producing new varieties with high photosynthetic efficiency and optimal assimilate distribution. The research was conducted in 2016‑2017 in Federal Scientific Center of Legumes and Groat Crops (Orel). Plants were grown on experimental field with density 1.2 million plants/ha on triplicated plots 1 m2. Wild pea accessions k-5322 (asiaticum), k-3370 (elatius), k-4014 (elatius) from VIR collection and varieties Temp and Stabil were used. Wild accessions k-3370 and k-5322 had more chlorophyll a, chlorophyll b and carotenoids then leafy Temp variety on 24.5 %, 28.2 %, 41.5 % and 13.3 %, 2.7 %, 18.7 % respectively. Unlike the cultivated pea, accessions k-3370 and k-5322 retain high level of chlorophylls a and b in ontogenesis longer time. After transition from bud formation to the beginning of seed filling content of chlorophylls a and b in accession k-3370 was at the same level (11.71 mg/g и 11.1 mg/g respectively), in accession k-5322 it decreased insignificantly from 11.31 mg/g to 9.72 mg/g. Nevertheless, in variety Temp content of chlorophylls a and b significantly decreased on 34.1 % after transition from bud formation to the seed filling. Wild accession k-3370 like pea varieties had low chlorophyll a/b ratio (2.92), but accession k-5322 had the highest value (3.26) of the ratio. In wild accession k-3370 and k-5322 the chlorophyll a/b ratio was changed in ontogenesis that is no-typical for Temp variety. Pea wild accessions can be considered as sources of valuable alleles determining the high level of chlorophylls and carotenoids


2015 ◽  
Vol 38 (5) ◽  
Author(s):  
Nidhi Verma ◽  
Surendra Singh ◽  
Yasin Jeshima Khan ◽  
Sushil Kumar ◽  
A K Singh

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.


Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1228
Author(s):  
Stefania Bennici ◽  
Mario Di Guardo ◽  
Gaetano Distefano ◽  
Giuseppina Las Casas ◽  
Filippo Ferlito ◽  
...  

The genus Pyrus is characterized by an S-RNase-based gametophytic self-incompatibility (GSI) system, a mechanism that promotes outbreeding and prevents self-fertilization. While the S-genotype of the most widely known pear cultivars was already described, little is known on the S-allele variability within local accessions. The study was conducted on 86 accessions encompassing most of the local Sicilian varieties selected for their traits of agronomic interest and complemented with some accessions of related wild species (P. pyrifolia Nakai, P. amygdaliformis Vill.) and some national and international cultivars used as references. The employment of consensus and specific primers enabled the detection of 24 S-alleles combined in 48 S-genotypes. Results shed light on the distribution of the S-alleles among accessions, with wild species and international cultivars characterized by a high diversity and local accessions showing a more heterogeneous distribution of the S-alleles, likely reflecting a more complex history of hybridization. The S-allele distribution was largely in agreement with the genetic structure of the studied collection. In particular, the “wild” genetic background was often characterized by the same S-alleles detected in P. pyrifolia and P. amygdaliformis. The analysis of the S-allele distribution provided novel insight into the contribution of the wild and international cultivars to the genetic background of the local Sicilian or national accessions. Furthermore, these results provide information that can be readily employed by breeders for the set-up of novel mating schemes.


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