Krishnanand P. Kulkarni

Mapping QTLs for 100-seed weight in an interspecific soybean cross of Williams 82 (Glycine max) and PI 366121 (Glycine soja)

Abstract. Seed weight can be an important component for soybean quality and yield. The objective of the present study was to identify quantitative trait loci (QTLs) for 100-seed weight by using 169 recombinant inbred lines (RILs) derived from the cross Williams 82 × PI 366121. The parental lines and RILs were grown for four consecutive years (2012–15) in the field. The seeds were harvested after maturity, dried and used to measure 100-seed weight. Analysis of variance indicated significant differences among the RILs for 100-seed weight. The environment had significant effect on seed-weight expression as indicated by the genotype × environment interaction. QTL analysis employing inclusive composite interval mapping of additive QTLs implemented in QTL IciMapping (Version 4.1) identified nine QTLs (LOD >3) on chromosomes 1, 2, 6, 8, 13, 14, 17 and 20. The individual QTLs explained phenotypic variation in the range 6.1–12.4%. The QTLs were detected in one or two environments, indicating major influence of the growing environment on seed-weight expression. Four QTLs identified in this study, qSW-02_1, qSW-06_1, qSW-13_1 and qSW-14_1, were found to be new QTLs. The findings of the study may be helpful to reveal the molecular genetic basis of the seed-weight trait in soybean.

Soybean Sprouts: A Review of Nutrient Composition, Health Benefits and Genetic Variation

Soybean [Glycine max (L.) Merr.] sprouts are highly digestible and a year around vegetable suitable for human consumption. Sprouting process causes a number of biochemical changes inside the seed, resulting in the accumulation of various primary and secondary metabolites. Due to such changes, sprouts contain high levels of health-promoting phytochemicals as compared to other vegetables. Sprouts are an excellent source of protein, amino acids, and vitamins, which provide numerous health benefits. Due to such advantages, soybean sprouts have been preferred as a part of daily diets in Korea and quality soybean sprouts are in high demand in the edible food market. To produce high quality soybean sprouts, several factors, including the choice of the variety, health benefits from sprout phytonutrients and inherent genetic variation for the sprout-related traits of the variety need to be considered. In this review, we have summarized literature on soybean sprout components, the health benefits, changes in nutritional factors during the sprouting process and the genetic variation among the cultivars developed for sprout usage. We have also reviewed procedures and factors like seed characteristics, temperature, chemical applications that influence the sprouting process. The information collectively presented here will be useful for understanding the progress of soybean cultivars developed for soybean sprout development and use.

Comparative genome analysis to identify SNPs associated with high oleic acid and elevated protein content in soybean

The objective of this study was to determine the genetic relationship between the oleic acid and protein content. The genotypes having high oleic acid and elevated protein (HOEP) content were crossed with five elite lines having normal oleic acid and average protein (NOAP) content. The selected accessions were grown at six environments in three different locations and phenotyped for protein, oil, and fatty acid components. The mean protein content of parents, HOEP, and NOAP lines was 34.6%, 38%, and 34.9%, respectively. The oleic acid concentration of parents, HOEP, and NOAP lines was 21.7%, 80.5%, and 20.8%, respectively. The HOEP plants carried both FAD2-1A (S117N) and FAD2-1B (P137R) mutant alleles contributing to the high oleic acid phenotype. Comparative genome analysis using whole-genome resequencing data identified six genes having single nucleotide polymorphism (SNP) significantly associated with the traits analyzed. A single SNP in the putative gene Glyma.10G275800 was associated with the elevated protein content, and palmitic, oleic, and linoleic acids. The genes from the marker intervals of previously identified QTL did not carry SNPs associated with protein content and fatty acid composition in the lines used in this study, indicating that all the genes except Glyma.10G278000 may be the new genes associated with the respective traits.

Harnessing the potential of forage legumes, alfalfa, soybean, and cowpea for sustainable agriculture and global food security

Substantial improvements in access to food and increased purchasing power are driving many people toward consuming nutrition-rich foods causing an unprecedented demand for protein food worldwide, which is expected to rise further. Forage legumes form an important source of feed for livestock and have potential to provide a sustainable solution for food and protein security. Currently, alfalfa is a commercially grown source of forage and feed in many countries. However, soybean and cowpea also have the potential to provide quality forage and fodder for animal use. The cultivation of forage legumes is under threat from changing climatic conditions, indicating the need for breeding cultivars that can sustain and acclimatize to the negative effects of climate change. Recent progress in genetic and genomic tools have facilitated the identification of quantitative trait loci and genes/alleles that can aid in developing forage cultivars through genomics-assisted breeding. Furthermore, transgenic technology can be utilized to manipulate the genetic makeup of plants to improve forage digestibility for better animal performance. In this article, we assess the genetic potential of three important legume crops, alfalfa, soybean, and cowpea in supplying quality fodder and feed for livestock. In addition, we examine the impact of climate change on forage quality and discuss efforts made in enhancing the adaptation of the plant to the abiotic stress conditions. Subsequently, we suggest the application of integrative approaches to achieve adequate forage production amid the unpredictable climatic conditions.

Characterization of an EMS-induced soybean mutant with an increased content of Af saponin and a new component Ab-δ in the seed hypocotyl

Saponins are one of the components present in the soybean seeds that have various functional properties. The chemical structures and concentration of soyasaponins affect the taste of the processed soyfood, thereby limiting its industrial applications. Therefore, it is important to understand saponin biosynthesis to explore natural and artificial variation in the saponin components, which can be modified to suit its application. The objective of the present study was to identify and characterize an EMS-induced soybean mutant with an altered saponin composition from a pool of 892 M4 lines. The mutant PE1905 showed an increased content of saponin Af (336.0%). The content of saponin Ab, DDMP-αg, and DDMP-βg was decreased in the mutant PE1905 by 89.3, 24.8, and 63.1%, respectively compared to the wild-type Pungsannamul. Additionally, four new components were detected in the mutant PE1905 that were absent in the wild type. Of these, the compound 4 (designated as Ab-δ) had the highest concentration, and therefore it was further characterized by HPLC and LC-PDA/MS/MS analysis to know the chemical structure, and molecular weight and formula. Considering these details, along with the alterations in the saponin Af and Ab concentrations, it was presumed that the Ab-δ acts as a precursor for the synthesis of saponin Af and Ab. Thus, we predicted a biosynthetic pathway from the Ab-δ to Ab saponin. The inheritance analysis showed that the concentration of saponin Ab-δ is controlled by a single recessive gene in the mutant PE1905. The results from the present study would be helpful in understanding the mechanisms behind altered seed saponin composition in soybeans.