Obtaining high-quality planting material for cultivation is a persisting challenge for yam (Dioscorea spp.) production in Africa. Efforts to provide a solution to this challenge have led to varying seed multiplication techniques but whose efficiency in maintaining the genetic purity of yam genotypes during the rapid multiplication process is yet unknown. Three improved varieties Swaswa, Kpamyo and Asiedu were multiplied through tissue culture, aeroponics system, field condition and vine cutting techniques. Leaf samples were collected at every stage of multiplication in the different techniques as well as the original mother plant for DNA fingerprinting. From a total of 16,922 SNP markers, an average heterozygosity of 0.091 was obtained with minor allele frequency of 0.119, and polymorphic information content of 0.166. The transition to transversion ratio was 62:38%. Hierarchical clustering of the genotypes and technologies discriminated the multiplied materials into three clusters with the first cluster consisting of only the variety Asiedu multiplied through aeroponics, vine and tubers collected from vine cutting and grown from the field. The second cluster consisted predominantly of the variety Kpamyo, with a little admixture from Asiedu. The third cluster consisted of only Swaswa. The different seed multiplication methods showed great potentials in conserving the genetic purity of genotypes used. Therefore, the use of these seed multiplication techniques could offer a lasting solution to the low multiplication ratio of yam without compromising the genetic integrity and offers a great opportunity for establishing a formal yam seed system.

Camelina (Camelina sativa (L.) Crantz), an oilseed crop, belongs to the Brassicaceae family. Two unique features of camelina in comparison with the main oil crops are an adaptation to different environments and also its unique oil composition. The development of doubled haploid plants is one of the essential methods for crop improvement. The study of genetic diversity is an important step in planning crop breeding programmes. This research was conducted to evaluate the genetic variation of 81 camelina doubled haploid lines obtained from 15 crosses by inter simple sequence repeat (ISSR) markers. The total number of amplified bands was 243, of which 239 bands (98.3%) showed polymorphism. The percentage of polymorphic bands varied between 93.75 and 100. The size of the bands ranged from 50 to 1700 base pairs. The informative ISSRs were identified by estimating marker features: polymorphism information content, effective multiplex ratio, marker index and resolving power. Three markers had higher resolving power values (9.88, 8.5 and 7.46) and were the most informative markers to identify the lines. Cluster analysis based on the complete algorithm divided the lines into five groups, indicating relatively clear configuration from the geographic distribution patterns of the parents of the doubled haploid lines. Principal coordinate analysis classified the 81 camelina doubled haploid lines into six groups. The ISSR markers detected high polymorphism to reveal the genetic variation of camelina lines. The findings of this research, along with the characterization of biochemical traits of the lines, can improve breeding programmes achieve high-yielding camelina varieties with higher and better oil content.

Angular leaf spot (ALS) caused by Pseudocercospora griseola is a major disease of french bean (Phaseolus vulgaris L.) worldwide. A good diversity of French bean is present in the Garhwal Himalayas of Uttarakhand, India, which is unexplored. The purpose of this study was to identify ALS-resistant accessions among local landraces of French bean in this region. One hundred seventy-six local accessions were collected from different villages of Garhwal, Uttarakhand. All the accessions were screened by four SCAR primers SN02 (Phg-2), SAA19, SM02, SBA16 (Phg-3), one STS primer TGA1.1 (Phg-1) and one SSR primer Pv-at006 (Phg-5). All the accessions were also screened for ALS resistance under field condition in the years 2019 and 2020. The disease-resistant score was recorded on 1–9 scale. After field screening, 48 accessions (19 resistant, 24 moderately resistant and five susceptible) were selected for in-vitro screening under screen house condition. These 46 accessions were artificially inoculated by two different isolates of P. griseola P5 and P9, which are the most virulent pathotype characterized by microbiology lab, College of Forestry, Tehri, Uttarakhand. After in-vitro screening, seven accessions (GFB-25, GFB-26, GFB-30, GFB-32, GFB-93, GFB-97 and GFB-136) were found resistant to both the isolates P5 and P9. The P. griseola-resistant accessions may further be used in future breeding programmes to develop new and more resistant varieties of French bean against ALS.

The plant Camellia fascicularis, belonging to family Theaceae, has high ornamental and medicinal value, and rare gene resources for genetic improvement of Camellia crops, but is currently threatened with extinction because of the unique and extremely small wild populations. Molecular markers have clarified the wild plant species’ genetic diversity structure, new gene resources and relationship with crops. This will be beneficial for conservation of these valuable crop-related wild species and crop improvement. In this study, we identified 95,979 microsatellite loci from 155,011 transcriptome unigenes, and developed 14 polymorphic expressed sequence tag-derived simple sequence repeat (EST-SSR) microsatellite markers for C. fascicularis. The number of alleles (Na) per locus was 2–8 with a mean of 4.86. The genetic diversity of 40 individuals from four natural populations of C. fascicularis was analysed using these polymorphic markers. The number of alleles (Na) for EST-SSR ranged from 2 to 5, with the expected heterozygosities (He) and observed heterozygosities (Ho) in all loci ranging from 0.183 to 0.683, and from 0.201 to 0.700, respectively, implying a rich genetic variation present in wild C. fascicularis populations. Moreover, the phylogenetic analysis among four populations, using the 14 EST-SSR markers developed in this study, grouped 40 individuals into three groups, which coincide with their geographic distribution. These results showed that 14 EST-SSR markers are available for the analysis of genetic variation in C. fascicularis populations and genetic improvement of new Camellias cultivars by interspecific hybridization, and are beneficial for conservation of the endangered species.

Rice crop is affected by different types of floods at different stages of the crop cycle. Constant efforts of researchers resulted in the development of rice varieties for anaerobic germination, flash floods and stagnant flooding by both conventional and molecular breeding approaches. Detection of QTLs for different types of floods in new genetic source (AC39416A) is needed to combat adverse effects of climate change. Present investigation was carried out to identify QTLs for flood tolerance using recombinant inbred lines derived from Indra and AC39416A. QTL mapping resulted in identification of QTLs, qAG3.1 on chromosome 3 for anaerobic germination and qSF10.1 on chromosome 10 for plant survival % under stagnant flooding. These QTLs explain 59.08 and 13.21% of phenotypic variance respectively. Two candidate genes were identified in qAG3.1 region, LOC_Os03g42130 gibberellin 20 oxidase2 and LOC_Os03g44170 glutathione S-transferase. The underlying mechanism might be the inhibition of gibberellic acid synthesis and thereby protecting seedlings from oxidative stress under anoxia condition. Genomic region of qSF10.1 revealed LOC_Os10g35020 glycosyltransferase and LOC_Os10g35050 aquaporin protein loci, which might be responsible for adaptive mechanism for plant survival % under stagnant flooding. This indicates that the new genetic resource AC39416A has an ability to adopt to different types of flood tolerance in response to environmental stress. Unveiling physiological and molecular mechanisms for flood tolerance in AC39416A using advanced omics studies would help in precise genomic selections for sustained production in flood-prone areas.

Foxtail millet (Setaria spp.) is an ancient cereal crop, having a short cropping cycle. Drought tolerance was assessed in this crop at an early growth stage and the extent of genetic diversity was measured between the foxtail millet genotypes, applying DNA markers. Tolerance of 18 foxtail millet genotypes was studied in vitro under four levels of polyethylene glycol (0, 10, 20 and 30% PEG-6000). PEG-6000 decreased final germination percentage and led to a reduction in shoot and root length with different stress levels. The genotypes ISe 869, ISe 1851 and yellow spike show superiority in stress tolerance for germination and the growth of root and shoot traits. They also clustered together in the biplot diagram and dendrogram of the genotypes based on the morphological traits. Marker polymorphism index (PI) was 80.36% and a total of 132 polymorphic alleles (4.00 alleles/locus) were obtained from 33 polymorphic primers. Polymorphic information content (0.54–0.83) was highly informative with an average value of 0.67. A dendrogram distributed the genotypes into five distinct clusters based on simple-sequence repeat (SSR) data, independent of their geographical distribution. A relationship was established between the SSR markers and the genotypes ability to tolerate drought stress. The SSR markers used could contribute to conducting DNA profiling of foxtail millet, and facilitating their use in future breeding programmes for drought tolerance in this crop. Based on water-stress experiment, three most tolerant genotypes: ISe 869, ISe 1851 and yellow spike are recommended to be cultivated under drought conditions around the world.

Although morphological plasticity has been widely known in various cactus genera, few studies have investigated the origin and molecular relationship between morphological variants from cacti. Morphological variants are relevant specimens because atypical, exotic and generally unique forms are preferred by cactus traders and collectors. The current study investigates the molecular relationship between the tortuosus and monstruosus ornamental variants of Cereus peruvianus used in landscapes. Polymorphisms in loci of simple-sequence repeats in DNA were used as molecular markers. The variants tortuosus and monstruosus, and plants with typically columnar and erect shoots cultivated in southern Brazil were retrieved from public parks and home gardens. High polymorphism, an indicative of vegetative propagation, and a moderate genetic divergence were detected at the molecular level in monstruosus and tortuosus plants. Artificial selection and vegetative propagation of the ornamental variants of Cereus may be inducing a moderate genetic divergence and formation of two heterologous groups with conservative genetic diversity. Polymorphism in Cereus variants revealed groups with contrasting genes among the variants tortuosus and monstruosus which may be useful for breeding to generate new and different new variants.

Date palm is a relatively salt- and drought-tolerant plant and more recent efforts have been focused on recognizing genes and pathways that confer stress tolerance in this species. The cDNA start codon targeted marker (cDNA–SCoT) technique is a novel, simple, fast and effective method for differential gene expression investigation. In the present study, this technique was exploited to identify differentially expressed genes during several stress treatments in date palm. A total of 12 SCoT primers combined with oligo-dT primers amplified differentially expressed fragments among the stress treatments and control samples. Differentially expressed fragments were highly homologous to known genes or encoded unclassified proteins with unknown functions. The expression patterns of the genes that had direct or indirect relationships with salinity and drought stress response were identified and their possible roles were discussed. This study suggests that the cDNA-SCoT differential display method is a useful tool to serve as an initial step for characterizing transcriptional changes induced by abiotic stresses and provide gene information for further study and application in genetic improvement and breeding in date palm.

The use of molecular markers is one of the most sensitive, powerful technologies for genetic purity assessment of seed lots. In this study, we aimed to develop a set of insertion and deletion (InDel) markers, through bioinformatics approaches, that may effectively distinguish three representative japonica rice (Oryza sativa L.) varieties, Nipponbare, Taichung 65 and Zhonghua11. The published whole-genome sequences of these varieties were aligned using BWA-MEM, followed by manual inspection for InDels of more than ten base pairs in size with the tview function of SAMtools. A set of ten InDel markers were thus identified and then validated by PCR in the three japonica rice varieties and their intercross F1 hybrids. Results showed that the InDel markers developed in this study could reliably distinguish these three japonica rice varieties. These molecular markers together with the detection method developed here can be applied to DNA-based genetic purity evaluation in rice breeding.