Genome-Wide Association Studies of Mineral Content in Common Bean

Micronutrient malnutrition is one of the main public health problems in many parts of the world. This problem raises the attention of all valuable sources of micronutrients for the human diet, such as common bean (Phaseolus vulgaris L.). In this research, a panel of 174 accessions representing Croatian common bean landraces was phenotyped for seed content of eight nutrients (N, P, K, Ca, Mg, Fe, Zn, and Mn), and genotyped using 6,311 high-quality DArTseq-derived SNP markers. A genome-wide association study (GWAS) was then performed to identify new genetic sources for improving seed mineral content. Twenty-two quantitative trait nucleotides (QTN) associated with seed nitrogen content were discovered on chromosomes Pv01, Pv02, Pv03, Pv05, Pv07, Pv08, and Pv10. Five QTNs were associated with seed phosphorus content, four on chromosome Pv07, and one on Pv08. A single significant QTN was found for seed calcium content on chromosome Pv09 and for seed magnesium content on Pv08. Finally, two QTNs associated with seed zinc content were identified on Pv06 while no QTNs were found to be associated with seed potassium, iron, or manganese content. Our results demonstrate the utility of GWAS for understanding the genetic architecture of seed nutritional traits in common bean and have utility for future enrichment of seed with macro– and micronutrients through genomics-assisted breeding.

Effects of Drought on Yield and Nutraceutical Properties of Beans (Phaseolus spp.) Traditionally Cultivated in Veneto, Italy

Beans are often grown in regions with climates that are susceptible to drought during the cultivation period. Consequently, it is important to identify bean accessions tolerant to drought conditions and assess the effect of drought on seeds’ nutraceutical properties. This study evaluated the effect of drought during different development stages (NES = never stressed; ALS = always stressed; SBF = stressed before flowering; SAF = stressed after flowering) on the yield and nutraceutical properties of six local bean varieties: Fasolo del Diavolo, Gialet, Posenati, Secle, D’oro, and Maron. Analysis of variance indicated that Gialet was not significantly affected by drought treatments, and Posenati under SBF and NES treatments had greater yields than under ALS and SAF treatments, whereas Secle under SBF produced 80% more seeds than under NES. Total phenols, antioxidant capacity, and calcium content were significantly different among the local varieties. Yield was significantly and positively correlated with seed calcium content and significantly and negatively correlated with protein, total phenols, and antioxidant capacity. The interaction between local varieties and treatment significantly affected seeds’ Zn content. Gialet and Maron seeds’ Zn contents were about 60 mg kg−1, almost double the average of commercial varieties. In summary, this study paves the way to the identification of potential bean varieties resistant to drought. Further molecular studies will help support these findings.

Genetic diversity studies for pod yield and nutrient uptake related traits in groundnut

Divergence analysis using Mahalanobis’s D2 statistics grouped 40 groundnut genotypes into eight clusters. The maximum inter-cluster distance was found between clusters II and VIII (D=183.23) followed by cluster VI and VIII indicating that the genotypes of these groups were highly divergent from each other. Among all the characters, pod yield per plant contributed the maximum to the diversity followed by leaf iron content (ppm) at 60 DAS, seed iron content (ppm) at maturity, seed calcium uptake (Kg ha-1) and seed calcium content (%) at maturity.The genotypes of above clusters revealed a substantial difference in the means for important yield contributing characters and form ideal parents for genetic improvement in groundnut.

Identification of nutrient and physical seed trait QTL in the model legume Lotus japonicus

Legume seeds have the potential to provide a significant portion of essential micronutrients to the human diet. To identify the genetic basis for seed nutrient density, quantitative trait locus (QTL) analysis was conducted with the Miyakojima MG-20 × Gifu B-129 recombinant inbred population from the model legume Lotus japonicus . This population was grown to seed under greenhouse conditions in 2006 and 2007. Phenotypic data were collected for seed calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn) concentrations and content. Data for physical seed traits (average seed mass and seed–pod allocation values) were also collected. Based on these phenotypic data, QTL analyses identified 103 QTL linked to 55 different molecular markers. Transgressive segregation, identified within this recombinant inbred population for both seed nutrient and physical traits, suggests new allelic combinations are available for agronomic trait improvement. QTL co-localization was also seen, suggesting that common transport processes might contribute to seed nutrient loading. Identification of loci involved in seed mineral density can be an important first step in identifying the genetic factors and, consequently, the physiological processes involved in mineral distribution to developing seeds. Longer term research efforts will focus on facilitating agronomic breeding efforts through ortholog identification in related crop legumes.

Determination of chemical composition of local black seeds Nigella sativa L

Chemical analysis for evaluation of Nigella sativa L. (black cumin) seeds showed a composition of Fat 39% ; Protein 28% ; Carbohydrate 21% ; Moisture 6% and Ash 4.5% . It was found that the black seed contains the following mineral element : Magnesium 0.26 gm /100gm seed ; Calcium 0.25 gm /100gm seed and Iron 25 ?g / gm /100gm seed ; zinc 4.51?g /gm /100gm seed and Copper 3.60 ?g /gm /100gm seed. The analysis also showed that mineral element I. e. ; lead ; Cobalt ; Nickel ; Chrom ; Cadmium and Aresenic are not present . It was found that the fat of the black seed contains the following fatty acids : Myristic 2.8%; Palmtic 16.6%; Stearic 0.8 % ; Oleic 13.79% ; Linoleic 64.2% and Arachidic 1.9% .

Influence of Cultural and Harvest Practices on Peanut Seed Quality1

Managing peanut (Arachis hypogaea L.) production for maximum yields often results in poor quality seed being produced. The objectives of this study were (1) to identify relationships between production practices and seed quality and (2) to evaluate the impact of harvesting and handling procedures on seed germination quality. Combining significantly reduced germination by an average of 9% for three years. Artificial drying had little effect on average seed quality. Percentage germination was significantly correlated with soil fertility, soil particle size, pod moisture, seed calcium, market grade and hull damage with the most consistent correlations occurring between seed calcium and germination. In general, the correlations were small, and no single production factor accounted for a large proportion of the variability found for seed quality.

Selection in Lupinus albus L. for lower seed manganese concentration

Seeds of 49 Mediterranean white lupin accessions and of 36 F5 families derived from 13 of them were analysed for manganese concentration. High concentrations in the range 1770–4640 µg g-1 dry matter were found in material grown near Canberra and lower ones (1060-2750 µg g-l) at Wagga Wagga, N.S.W. A small number of L. angustifolius L. lines grown under comparable conditions at both sites had 7- to 70-fold lower concentrations of manganese in their seeds than L. albus. The means for accessions and families of L. albus varied widely and continuously about the site means. High alkaloid lines had approximately two-thirds the manganese concentration of low alkaloid lines. Seeds from primary inflorescences had 6% lower manganese concentrations than those from higher order inflorescences. About one-quarter of the variation within the low alkaloid class was associated with seed yield variation, there being a negative correlation between these traits. There was no line x site interaction. Broad sense heritabilities at Canberra and Wagga Wagga were moderately high, so that selection for lower concentrations should be effective. The results suggest that selection for higher yield could be almost as effective as direct selection in reducing seed manganese concentration. The reduction should be sufficient to enable white lupin seeds, grown on soils no higher in available manganese than those used in this study at Canberra, to be safely used as a high protein supplement in pig and poultry rations. Selection for lower seed manganese should not affect seed calcium, phosphorus or protein concentrations, but would tend to increase seed yield and plant height at maturity.