Development and characterization of InDel markers for Lupinus luteus L. (Fabaceae) and cross-species amplification in other Lupin species

Comparisons of Chloroplast Genome Mutations among 13 Samples of Oil-Tea Camellia from South China

The differences in cpDNA SNPs and InDels of 13 samples from single trees of different species or populations of oil-tea camellia in South China were examined in this study, and phylogenetic trees were reconstructed based on CDSs and non-CDSs of cpDNAs to research the evolutionary relationships among all samples. The SNPs of all samples included all kinds of substitutions, and the frequency of the transition from AT to GC was highest; meanwhile, the frequencies of all kinds of transversions differed among the samples, and the SNPs exhibited polymorphism. The SNPs were distributed in all the different functional regions of cpDNAs, and approximately half of all SNPs in exons led to missense mutations and the gain or loss of termination codons. There were no InDels in the exons of any cpDNA samples, except those retrieved from Camellia gigantocarpa, although this InDel did not lead to a frame shift. The InDels of all cpDNA samples were unevenly distributed in the intergenic region and upstream and downstream of genes. The genes, regions of the same gene, sites and mutation types in the same region related to the distributions of SNPs, and InDels were inconsistent among samples. The 13 samples were divided into 2 clades and 7 or 6 subclades, and the samples of species from the same sections of the Camellia genus did not belong to the same subclades. Meanwhile, the genetic relationship between the samples of Camellia vietnamensis and the undetermined species from Hainan Province or the population of C. gauchowensis in Xuwen was closer than that between C. vietnamensis and the population of C. gauchowensis in Luchuan, and the genetic relationship among C. osmantha, C. vietnamensis and C. gauchowensis was very close. In sum, SNPs and InDels in the different cpDNAs resulted in variable phenotypes among the different species or populations, and they could be developed into molecular markers for studies on species and population identification and phylogenetic relationships. The conclusion from the identification of undetermined species from Hainan Province and the phylogenetic relationships among 13 oil-tea camellia samples based on cpCDS and cpnon-CDS sequences were the same as those from the former report.

The genetic diversity and population structure of Sophora alopecuroides (Faboideae) as determined by microsatellite markers developed from transcriptome

Sophora alopecuroides (Faboideae) is an endemic species, mainly distributed in northwest China. However, the limited molecular markers range for this species hinders breeding and genetic studies. A total of 20,324 simple sequence repeat (SSR) markers were identified from 118,197 assembled transcripts and 18 highly polymorphic SSR markers were used to explore the genetic diversity and population structure of S. alopecuroides from 23 different geographical populations. A relatively low genetic diversity was found in S. alopecuroides based on mean values of the number of effective alleles (Ne = 1.81), expected heterozygosity (He = 0.39) and observed heterozygosity (Ho = 0.55). The results of AMOVA indicated higher levels of variation within populations than between populations. Bayesian-based cluster analysis, principal coordinates analysis and Neighbor-Joining phylogeny analysis roughly divided all genotypes into four major groups with some admixtures. Meanwhile, geographic barriers would have restricted gene flow between the northern and southern regions (separated by Tianshan Mountains), wherein the two relatively ancestral and independent clusters of S. alopecuroides occur. History trade and migration along the Silk Road would together have promoted the spread of S. alopecuroides from the western to the eastern regions of the northwest plateau in China, resulting in the current genetic diversity and population structure. The transcriptomic SSR markers provide a valuable resource for understanding the genetic diversity and population structure of S. alopecuroides, and will assist effective conservation management.

Development of gene-based molecular markers tagging low alkaloid pauper locus in white lupin (Lupinus albus L.)

White lupin (Lupinus albus L.) is a legume grain crop cultivated since ancient Greece and Egypt. Modern white lupin cultivars are appreciated as a source of protein with positive nutraceutical impact. However, white lupins produce anti-nutritional compounds, quinolizidine alkaloids, which provide bitter taste and have a negative influence on human health. During domestication of this species, several recessive alleles at unlinked loci controlling low alkaloid content were selected. One of these loci, pauper, was exploited worldwide providing numerous low-alkaloid cultivars. However, molecular tracking of pauper has been hampered due to the lack of diagnostic markers. In the present study, the synteny-based approach was harnessed to target pauper locus. Single-nucleotide polymorphisms flanking pauper locus on white lupin linkage map as well as candidate gene sequences elucidated from the narrow-leafed lupin (L. angustifolius L.) chromosome segment syntenic to the pauper linkage group region were transformed to PCR-based molecular markers. These markers were analyzed both in the mapping population and world germplasm collection. From fourteen markers screened, eleven were localized at a distance below 1.5 cM from this locus, including five co-segregating with pauper. The linkage of these markers was confirmed by high LOD values (up to 58.4). Validation performed in the set of 127 bitter and 23 sweet accessions evidenced high applicability of one marker, LAGI01_35805_F1_R1, for pauper locus selection, highlighted by the low ratio of false-positive scores (2.5%). LAGI01_35805 represents a homolog of L. angustifolius acyltransferase-like (LaAT) gene which might hypothetically participate in the alkaloid biosynthesis process in lupins.

Genetics and Breeding of Lupinus mutabilis: An Emerging Protein Crop

Protein crops have gained increasing interest in recent years, as a transition towards plant-protein based diets appears pivotal to ensure global food security and preserve the environment. The Andean species Lupinus mutabilis emerges as an ideal protein crop with great potential for Europe and other regions with temperate climates. This species is characterized by oil and protein content similar to soybean and is highly valued for its adaptability to colder climates and low input agriculture on marginal land. However, its introduction outside the Andes has yet to take off. To date, L. mutabilis remains an under-studied crop, lacking high yield, early maturity and a consistent breeding history. This review paper identifies L. mutabilis limitations and potential uses, and suggests the main breeding targets for further improvement of this crop. It also highlights the potential of new molecular tools and available germplasm resources that can now be used to establish L. mutabilis as a viable protein crop.