Background: Cucumber, Cucumis sativus L. (2n = 2 × = 14) and melon, C. melo L. (2n = 2 × = 24) are two important vegetable species in the genus Cucumis (family Cucurbitaceae). Both species have an Asian origin that diverged approximately nine million years ago. Cucumber is believed to have evolved from melon through chromosome fusion, but the details of this process are largely unknown. In this study, comparative genetic mapping between cucumber and melon was conducted to examine syntenic relationships of their chromosomes.
Results: Using two melon mapping populations, 154 and 127 cucumber SSR markers were added onto previously reported F(2)- and RIL-based genetic maps, respectively. A consensus melon linkage map was developed through map integration, which contained 401 co-dominant markers in 12 linkage groups including 199 markers derived from the cucumber genome. Syntenic relationships between melon and cucumber chromosomes were inferred based on associations between markers on the consensus melon map and cucumber draft genome scaffolds. It was determined that cucumber Chromosome 7 was syntenic to melon Chromosome I. Cucumber Chromosomes 2 and 6 each contained genomic regions that were syntenic with melon chromosomes III+V+XI and III+VIII+XI, respectively. Likewise, cucumber Chromosomes 1, 3, 4, and 5 each was syntenic with genomic regions of two melon chromosomes previously designated as II+XII, IV+VI, VII+VIII, and IX+X, respectively. However, the marker orders in several syntenic blocks on these consensus linkage maps were not co-linear suggesting that more complicated structural changes beyond simple chromosome fusion events have occurred during the evolution of cucumber.
Conclusions: Comparative mapping conducted herein supported the hypothesis that cucumber chromosomes may be the result of chromosome fusion from a 24-chromosome progenitor species. Except for a possible inversion, cucumber Chromosome 7 has largely remained intact in the past nine million years since its divergence from melon. Meanwhile, many structural changes may have occurred during the evolution of the remaining six cucumber chromosomes. Further characterization of the genomic nature of Cucumis species closely related to cucumber and melon might provide a better understanding of the evolutionary history leading to modern cucumber.
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http://dx.doi.org/10.1186/1471-2164-12-396 | DOI Listing |
J Appl Genet
December 2024
Department of Plant Genetics Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, SGGW, Warsaw, Poland.
Plant regeneration in tissue cultures is crucial for the application of biotechnological methods to plant breeding. However, the genetic basis of in vitro plant regeneration is not fully understood. For cucumber, regeneration protocols from different types of explants have been reported, but thus far, the molecular basis of regeneration from cotyledon explants has only been studied.
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December 2024
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture and Rural Affairs/Northeast Agricultural University, Harbin, 150030, China.
Pumpkin (Cucurbita maxima D.) is typically monoecious with individual male and female flowers, and its yield is associated with the degree of femaleness, i.e.
View Article and Find Full Text PDFTheor Appl Genet
December 2024
College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Mutations in the CsEMS1 gene result in male sterility and reduced wart number and density. Male sterility and fruit wart formation are two significant agronomic characteristics in cucumber (Cucumis sativus), yet knowledge of our underlying genetics is limited. In this study, we identified an EMS-induced male sterility and few small warts mutant (msfsw).
View Article and Find Full Text PDFPlant Biotechnol J
December 2024
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
The interaction dynamics of homologous chromosomes during meiosis, such as recognition, pairing, synapsis, recombination, and segregation are vital for species fertility and genetic diversity within populations. Meiotic crossover (CO), a prominent feature of meiosis, ensures the faithful segregation of homologous chromosomes and enriches genetic diversity within a population. Nevertheless, visually distinguishing homologous chromosomes and COs remains an intractable challenge in cytological studies, particularly in non-model or plants with small genomes, limiting insights into meiotic dynamics.
View Article and Find Full Text PDFStress Biol
December 2024
State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Fruit quality and yield are reduced when cucumber (Cucumis sativus L.) plants are exposed to low temperature (LT) stress, yet, the inheritance and genes linked to cold tolerance in adult plants have not been reported yet. Here, the LT-tolerance of 120 cucumber accessions representing four ecotypes were evaluated by GWAS, and also, in 140 recombinant inbred lines (RILs) derived from a biparental cross.
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