scholarly journals Potato Landraces and Their Wild Relatives in 3 Micro-centers of Diversity in Ecuador: Farmers' Perception and Ecogeography

Author(s):  
Álvaro Ricardo Monteros-Altamirano ◽  
A. Monteros-Altamirano ◽  
F. Yumisaca-Jiménez ◽  
R. Aucancela ◽  
J. Coronel ◽  
...  

Abstract Ecuador is one of the centers of diversity for wild and cultivated potatoes. Three micro-centers of diversity were previously identified based on germplasm collecting passport data of potato landraces and their wild relatives. The objective of this study was to understand the potential hybridization dynamic of the genetic diversity present in situ in these micro-centers (provinces of Carchi, Chimborazo and Loja in Ecuador) by means of: 1. Reviewing the possibility of an eventual genetic cross within intercropped potato landraces through surveys to local producers; 2. Reviewing the possibility of potato landraces crossing with their wild relatives, also according to local producers; and 3. Map the actual geographic location of recent collections of potato landrace and wild potato relatives in the study areas. Information from farmers and eco-geographic data demonstrated that there is no potential crossing between wild and cultivated potato species. Probably the existing genetic variability in Ecuador has been accumulated since the historical movement of potato landraces by American ancestors from the center of origin in Peru and Bolivia and the continuum knowledge and seed sharing besides the conscious and unconscious selection of potato landraces by local farmers for centuries. Additionally, we discuss options to conserve both cultivated and wild potato species in Ecuador due to apparent current genetic erosion processes.

2011 ◽  
Vol 101 (9) ◽  
pp. 1074-1080 ◽  
Author(s):  
X. K. Cai ◽  
D. M. Spooner ◽  
S. H. Jansky

A major justification for taxonomic research is its assumed ability to predict the presence of traits in a group for which the trait has been observed in a representative subset of the group. Similarly, populations in similar environments are expected to be more alike than populations in divergent environments. Consequently, it is logical to assume that taxonomic relationships and biogeographical data have the power to predict the distribution of disease resistance phenotypes among plant species. The objective of this study was to test predictivity in a group of widely distributed wild potato species, based on hypotheses that closely related organisms (taxonomy) or organisms from similar environments (biogeography) share resistance to a simply inherited trait (Potato virus Y [PVY]). We found that wild potato species with an endosperm balance number (EBN) of 1 (a measure of cross compatibility) shared resistances to PVY more than species with different EBN values. However, a large amount of variation was found for resistance to PVY among and within species. We also found that populations from low elevations were more resistant than those from high elevations. Because PVY is vectored by aphids, we speculate that the distribution of aphids may determine the level of selection pressure for PVY resistance.


Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 732
Author(s):  
Fergus Meade ◽  
Ronald Hutten ◽  
Silke Wagener ◽  
Vanessa Prigge ◽  
Emmet Dalton ◽  
...  

Wild potato species continue to be a rich source of genes for resistance to late blight in potato breeding. Whilst many dominant resistance genes from such sources have been characterised and used in breeding, quantitative resistance also offers potential for breeding when the loci underlying the resistance can be identified and tagged using molecular markers. In this study, F1 populations were created from crosses between blight susceptible parents and lines exhibiting strong partial resistance to late blight derived from the South American wild species Solanum microdontum and Solanum pampasense. Both populations exhibited continuous variation for resistance to late blight over multiple field-testing seasons. High density genetic maps were created using single nucleotide polymorphism (SNP) markers, enabling mapping of quantitative trait loci (QTLs) for late blight resistance that were consistently expressed over multiple years in both populations. In the population created with the S. microdontum source, QTLs for resistance consistently expressed over three years and explaining a large portion (21–47%) of the phenotypic variation were found on chromosomes 5 and 6, and a further resistance QTL on chromosome 10, apparently related to foliar development, was discovered in 2016 only. In the population created with the S. pampasense source, QTLs for resistance were found in over two years on chromosomes 11 and 12. For all loci detected consistently across years, the QTLs span known R gene clusters and so they likely represent novel late blight resistance genes. Simple genetic models following the effect of the presence or absence of SNPs associated with consistently effective loci in both populations demonstrated that marker assisted selection (MAS) strategies to introgress and pyramid these loci have potential in resistance breeding strategies.


Plant Disease ◽  
2020 ◽  
pp. PDIS-06-20-1367 ◽  
Author(s):  
Hari S. Karki ◽  
Shelly H. Jansky ◽  
Dennis A. Halterman

Late blight (LB) of potato is considered one of the most devastating plant diseases in the world. Most cultivated potatoes are susceptible to this disease. However, wild relatives of potatoes are an excellent source of LB resistance. We screened 384 accessions of 72 different wild potato species available from the U.S. Potato GeneBank against the LB pathogen Phytophthora infestans in a detached leaf assay (DLA). P. infestans isolates US-23 and NL13316 were used in the DLA to screen the accessions. Although all plants in 273 accessions were susceptible, all screened plants in 39 accessions were resistant. Resistant and susceptible plants were found in 33 accessions. All tested plants showed a partial resistance phenotype in two accessions, segregation of resistant and partial resistant plants in nine accessions, segregation of partially resistant and susceptible plants in four accessions, and segregation of resistant, partially resistant, and susceptible individuals in 24 accessions. We found several species that were never before reported to be resistant to LB: Solanum albornozii, S. agrimoniifolium, S. chomatophilum, S. ehrenbergii, S. hypacrarthrum, S. iopetalum, S. palustre, S. piurae, S. morelliforme, S. neocardenasii, S. trifidum, and S. stipuloideum. These new species could provide novel sources of LB resistance. P. infestans clonal lineage-specific screening of selected species was conducted to identify the presence of RB resistance. We found LB resistant accessions in Solanum verrucosum, Solanum stoloniferum, and S. morelliforme that were susceptible to the RB overcoming isolate NL13316, indicating the presence of RB-like resistance in these species.


2019 ◽  
Vol 99 (6) ◽  
pp. 873-884 ◽  
Author(s):  
Qiaoyu Wu ◽  
Tianjiu He ◽  
Hui Liu ◽  
Xiaobo Luo ◽  
Wang Yin ◽  
...  

Potato cultivars are sensitive to frost; thus, freezing damage often results in heavy loss of potato yield. In this study, two wild potato species, Solanum acaule W3, which is frost-resistant and has cold-acclimation ability, and Solanum cardiophyllum Cph12, which is frost-sensitive and cannot be cold-acclimated, were used to research the cell structure and physiological changes that occur during cold acclimation. The results showed that the frost resistance of W3 was enhanced by cold acclimation, while the frost resistance of Cph12 did not change. The subcellular characteristics related to the enhancement of freezing resistance mainly include a decrease in the proportion of the vacuole to total cell volume, integrity of the biomembrane, and orderly arrangement of grana lamellae. At the physiological level, the W3 damage index was correlated with membrane lipid peroxidation system indices (including chlorophyll, malondialdehyde, and the difference between relative conductivity before and after freezing treatment in W3), the activity of the antioxidant enzymes superoxide dismutase and catalase, the contents of the osmotic regulators proline and soluble protein, and the contents of the endogenous hormones salicylic acid (SA), indole acetic acid/abscisic acid (IAA/ABA), and SA/ABA, which indicated that cold acclimation enhanced the freezing resistance of wild potato species W3 by enhancing its original cold-tolerance characteristics. The results could be useful to clarify the cold resistance mechanism of plants, and to provide a theoretical basis for cold-resistance breeding.


2013 ◽  
Vol 137 (10) ◽  
pp. 739-750 ◽  
Author(s):  
F. G. Horgan ◽  
D. T. Quiring ◽  
A. Lagnaoui ◽  
Y. Pelletier

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