Genetic Control of Cadmium Concentration in Soybean Seeds

Cadmium (Cd) is a chemical element present in the soil. At high concentrations Cd can cause physiological and morphological damages to plants and it is highly toxic to human beings. Minimizing the intake of Cd and other heavy metals from food consumption is an important health issue. Efforts have been made to identify genetic elements that are involved in Cd detoxification in plants. Heavy metal transporter 3 (HMA3) plays a role in sequestration of Cd into vacuoles in soybean (Glycine max). Inheritance studies revealed that low Cd accumulation in soybean seed is controlled by a major gene (Cda1) with the allele for low accumulation being dominant. Major QTL for seed Cd accumulation, Cda1 and cd1, have been identified independently for low Cd accumulation and both mapped to the same location as on LG-K (Chromosome 9) with simple sequence repeat (SSR) markers. A single nucleotide substitution causing a loss of function of the ATPase was found. The SSR markers linked to the Cda1 and Cd1gene(s)/or QTLs and the SNP marker in the P1B-ATPase metal ion transporter gene in soybean can be utilized in marker assisted selection (MAS) for developing food grade soybean varieties

Food Grade Soybean Breeding, Current Status and Future Directions

Soybeans possess average 20% oil and 40% protein content and are a major source of protein and fatty acids in human and animal nutrition. Soybean cultivars are classified as commodity type, which are used for edible or industrial oil and animal feed, and food-type, which are used for human consumption in fermented foods and non-fermented foods. Major breeding targets for food grade soybeans are high protein and sucrose content. Developing cultivars with desired seed size and appearance depends on the type of soyfood for which the soybeans are destined. Seed with high protein content (>45%), low oil content, high sucrose, and low oligosaccharide content are suitable for making soymilk and tofu. For soyfood such as natto, soybean seed with a high content of carbohydrates are preferred. Since, molecular markers linked to the target food traits have been developed, transfer of the food grade traits among soybean varieties is possible through marker-assisted selection (MAS) to track the target gene/QTLs. Introgression of wild soybean alleles through genomics assisted breeding (e.g., GWAS, haplotype blocks, NIL, etc.), high-throughput phenotyping, mutagenesis and genome engineering/editing would improve protein without yield drag, pleiotropic effects, and background/allelic effects in breeding food grade soybean

Cross-species amplification and genetic variation among blackgram genotypes using SSR markers developed from mungbean DNA sequence scaffolds harbouring putative resistance genes

The cross species amplification of 97 mungbean derived resistance gene-SSR markers were investigated for diversity analysis in a set of 44 blackgram genotypes. A total of 68(70%) SSR markers showed amplification in blackgram. Our of 68 markers, thirty randomly selected markers were used to study the genetic variation among 44 blackgram genotypes varying for yellow mosaic disease (YMD) and powdery mildew disease (PMD) reaction. Thirty SSR primers collectively amplified 90 alleles in blackgram with an average of three alleles/locus. The polymorphic information content (PIC) of the SSR markers ranged from 0 to 0.86 with an average of 0.43. Cluster analysis based on UPGMA neighbour-joining method grouped the 44 genotypes into seven clusters. The genotypes NDU-1 and PU-19 were observed to be highly dissimilar with similarity coefficient of 0.27 in comparison to other genotypes. YMD and PMD resistant and susceptible genotypes could be differentiated by three (MRGSSR 12, MRGSSR 56, MRGSSR 77) and four SSR markers (MRGSSR12, MRGSSR 32, MRGSSR56 and MRGSSR65), respectively. Two of these markers viz., MRGSSR12 and MRGSSR56 were mutually effective in differentiating YMD and PMD resistant genotypes. These were located in mungbean scaffolds JJMO01002369 and JJMO01001477 and exhibited homology with TMV resistance protein N and DNA damage-repair/toleration protein DRT100, respectively

Impact of electron beam and ethyl methane sulphonate on chlorophyll mutations in rice genotypes ASD 16 and Norungan

Induced mutagenesis facilitates the creation of novel gene combinations within a plant genome, preserving its basic structure. This study investigates the impact of electron beam radiation and ethyl methane sulphonate (EMS) on chlorophyll mutations in rice genotypes, ASD 16 and Norungan. The seeds were irradiated with five different doses of electron beam and EMS during rabi 2021-22. The M1 generation was assessed for seedling survival, seedling height and spikelet fertility followed by an identification of chlorophyll mutants in the M2 generation. At specific mutagen doses, ASD 16 and Norungan exhibited the genotypic difference for chlorophyll mutants. Various chlorophyll mutations, such as albino, chlorina, xantha, striata, viridis, albomaculata, alboviridis and xanthoviridis were observed. ASD 16 was more sensitive to both mutagens, while Norungan showed a broader response. EMS proved to be a more effective in inducing mutations than the electron beam. Lower and moderate mutagen doses demonstrated higher efficiency indicating the importance of optimizing mutagenic conditions. This study illuminates the significance of chlorophyll mutants genetic makeup varietal differences. The strong and diverse response observed in Norungan underscores its suitability for mutation breeding programmes. These findings contribute to the efficient utilisation of mutagenesis in improving rice traits providing practical implications for elevating crop quality and promoting genetic diversity in rice cultivation

Comparative Metabolomic Profiling of Horse Gram (Macrotyloma uniflorum (Lam.) Verdc.) Genotypes for Horse Gram Yellow Mosaic Virus Resistance

Horse gram (Macrotyloma uniflorum (Lam.) Verdc.) is an under-utilized legume grown in India. It is a good source of protein, carbohydrates, dietary fiber, minerals, and vitamins. We screened 252 horse gram germplasm accessions for horse gram yellow mosaic virus resistance using the percent disease index and scaling techniques. The percentage values of highly resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible were 0.34, 13.89, 38.89, 46.43, and 0.34, respectively. Repetitive trials confirmed the host-plant resistance levels, and yield loss was assessed. The present disease index ranged from 1.2 to 72.0 and 1.2 to 73.0 during the kharif and rabi seasons of 2018, respectively. The maximum percent yield loss was noticed in the HS (75.0 -89.4), while HR possessed the minimum (1.2-2.0). The methanolic leaf extracts of highly resistant and highly susceptible genotypes with essential controls were subjected to gas chromatography-mass spectrometry analysis. Differential accumulation of metabolites was noticed, and a total of 81 metabolites representing 26 functional groups were identified. Both highly resistant and susceptible genotypes harbored eight unique classes, while ten biomolecules were common. The hierarchical cluster analysis indicated a distinct metabolite profile. Fold change in the common metabolites revealed an enhanced accumulation of sugars, alkanes, and carboxylic acids in the highly resistant genotype. The principal component analysis plots explained 93.7% of the variation. The metabolite profile showed a significant accumulation of three anti-viral (octadecanoic acid, diphenyl sulfone, and 2-Aminooxazole), one insecticidal (9,10-Secocholesta-5,7,10(19)-triene-3,24,25-triol), one antifeedant (cucurbitacin B), and six metabolites with unknown biological function in the highly resistant genotype

Revealing genetic variation in mini core germplasm of urdbean (Vigna mungo (L.) Hepper)

A set of 47 urdbean genotypes including 12 promising varieties and 34 popular land races and a popular OUAT variety “Ujala” (standard check) were characterized for genetic variation based on molecular markers and morpho-economic traits. The molecular marker- based genotyping revealed a tremendous higher level of polymorphism (97.05%) with high average PIC (polymorphic information content) value (0.75). ISSR 1357 was considered highly informative that revealed the highest PIC (0.87) and marker index value (MI:5.25). An 840 bp allele (band) was characteristic to Kantapada local - A, Kendrapada local-D, and Nayagarh local - C. Such genotype- specific finger-printing may serve for reliable varietal characterization and elimination of duplicates. The test genotypes were grouped into six distinct clusters. TU 10-13, LBG 623, TAU 1, OBG 33, LBG 17 and PU 31 were highly divergent. PU 31 had inherent high yield potential (˃5.0q/ha) with known YMV resistance. The above divergent high yielding test genotypes may serve as candidate varieties for further genetic improvement using recombination breeding

Revealing genetic variation in mini core germplasm of urdbean (Vigna mungo (L.) Hepper)

91-99A set of 47 urdbean genotypes including 12 promising varieties and 34 popular land races and a popular OUAT variety “Ujala” (standard check) were characterized for genetic variation based on molecular markers and morpho-economic traits. The molecular marker- based genotyping revealed a tremendous higher level of polymorphism (97.05%) with high average PIC (polymorphic information content) value (0.75). ISSR 1357 was considered highly informative that revealed the highest PIC (0.87) and marker index value (MI:5.25). An 840 bp allele (band) was characteristic to Kantapada local - A, Kendrapada local-D, and Nayagarh local - C. Such genotype- specific finger-printing may serve for reliable varietal characterization and elimination of duplicates. The test genotypes were grouped into six distinct clusters. TU 10-13, LBG 623, TAU 1, OBG 33, LBG 17 and PU 31 were highly divergent. PU 31 had inherent high yield potential (˃5.0q/ha) with known YMV resistance. The above divergent high yielding test genotypes may serve as candidate varieties for further genetic improvement using recombination breeding

Molecular marker-based characterization in candidate plus trees of Pongamia pinnata, a potential biodiesel legume

Molecular marker studies provide valid guidelines for collection, characterization and selective cultivation of elite Pongamia germplasm that can be exploited further for its improvement through breeding and marker assisted selection for improved characters and oil yield towards biodiesel production

Genetic Patterns of Domestication in Pigeonpea (Cajanus cajan (L.) Millsp.) and Wild Cajanus Relatives

Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providing significant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base, pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that would benefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotide polymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79 accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographically clustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzed Cajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent gene flow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species. Evidence supports that primary domestication occurred in India, with a second and more recent nested population bottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelic variation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which we report a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversity than the progenitor clade of wild Indian species, indicating a severe “domestication bottleneck” during pigeonpea domestication