Molecular characterization of a farmer-preferred maize landrace population from a multiple-stress-prone subtropical lowland environment

Makore F, Gasura E, Souta C, Mazamura U, Derera J, Zikhali M, Kamutando CN, Magorokosho C, Dari S. 2021. Molecular characterization of a farmer-preferred maize landrace population from a multiple-stress-prone subtropical lowland environment. Biodiversitas 22: 769-777. The study was conducted to assess genetic diversity of 372 maize lines using 116 single nucleotide polymorphism (SNP) markers. Three hundred and forty-seven lines were S1 lines (coded J lines) from a local maize landrace population and twenty-five were the widely used standard lines. The number of alleles per marker ranged from two to four and the average was three alleles. The average polymorphic information content (PIC) value of 0.405 indicates high genetic diversity for maize lines evaluated in this study. Population structure revealed three distinct sub-populations. Sub-population 1 contained two J lines; sub-population 2 contained five J lines and sub-population 3 contained the rest of the J lines and all the standard lines. Analysis of molecular variance (AMOVA) identified 22% variance among and 78% variance within the three subpopulations, indicating high gene exchange and low genetic differentiation. Hierarchical cluster analysis further divided the lines into nine subgroups placing some of the J lines into known heterotic groups', i.e., J30_3, J393_4, J393_3, and J393_1 in CIMMYT heterotic group B. Allelic variation observed can be a source of allele combination for breeding programs interested in widening their genetic base. The private alleles that were present in the J lines suggest availability of stress-tolerant genes that breeders can incorporate in new hybrids.

Impact of merging commercial breeding lines on the genetic diversity of Landrace pigs

Background The pig breeding industry has undergone a large number of mergers in the past decades. Various commercial lines were merged or discontinued, which is expected to reduce the genetic diversity of the pig species. The objective of the current study was to investigate the genetic diversity of different former Dutch Landrace breeding lines and quantify their relationship with the current Dutch Landrace breed that originated from these lines. Results Principal component analysis clearly divided the former Landrace lines into two main clusters, which are represented by Norwegian/Finnish Landrace lines and Dutch Landrace lines. Structure analysis revealed that each of the lines that are present in the Dutch Gene bank has a unique genetic identity. The current Dutch Landrace breed shows a high level of admixture and is closely related to the six former lines. The Dumeco N-line, which is conserved in the Dutch Gene bank, is poorly represented in the current Dutch Landrace. All seven lines (the six former and the current line) contribute almost equally to the genetic diversity of the Dutch Landrace breed. As expected, the current Dutch Landrace breed comprises only a small proportion of unique genetic diversity that was not present in the other lines. The genetic diversity level, as measured by Eding’s core set method, was equal to 0.89 for the current Dutch Landrace breed, whereas total genetic diversity across the seven lines, measured by the same method, was equal to 0.99. Conclusions The current Dutch Landrace breed shows a high level of admixture and is closely related to the six former Dutch Landrace lines. Merging of commercial Landrace lines has reduced the genetic diversity of the Landrace population in the Netherlands, although a large proportion of the original variation is maintained. Thus, our recommendation is to conserve breeding lines in a gene bank before they are merged.

Characterization of a Novel Porcine CSN2 Polymorphism and Its Distribution in Five European Breeds

Here, we describe a novel porcine β-casein (CNS2) polymorphism, initially identified using the isoelectric focusing (IEF) technique, and provide its distribution in five European breeds. Porcine CSN2 cDNA samples, from sows identified using IEF as carriers of polymorphic variants, were sequenced, and based on the sequence alignments, a genotyping assay was developed. The distribution of the polymorphism was investigated by genotyping 167 sows. Population genetic indexes were computed using POPGENE32 version 1.32. Sequence alignments revealed that the mutation which caused the different β-casein IEF migration profiles was c.647G>A, a substitution located in exon 7, which modifies the amino acid from position 201 of the mature protein from arginine to glutamine. The frequency of the G allele was 0.965 in the investigated Landrace population (number of individuals genotyped n = 67), one in the Pietrain population (n = 40), 0.705 in the Large White population (n = 36), 0.885 in the Bazna population (n = 13), and 0.555 in the Mangalita population (n = 11). For all breeds, except Pietrain (monomorphic), the genotype distribution was in accordance with the Hardy–Weinberg equilibrium. Given that β-casein is the most important protein in sows’ milk, a polymorphism like the one described here may prove interesting for marker-assisted selection.

Phenolic content and antioxidant activity of wholegrain breads from modern and old wheat (Triticum aestivum L.) cultivars and ancestors enriched with wheat sprout powder

In this study, we compared nutritional characteristics of breads from wholegrain flours of three modern cultivars, four old cultivars and one landrace population of common wheat (Triticum aestivum), one Khorasan (Triticum turgidum var turanicum) accession and one einkorn (Triticum monococcum) cultivar. One bread from refined flour was also included. All flours were enriched or not with 5% (w:w) of wheat sprout powder (WSP) to obtain enriched breads (EB) or control breads (CB), respectively. Total phenolics and flavonoids, reducing power, radical scavenging and thiobarbituric acid reactive substances production inhibition were measured on bread aqueous extracts. CB from old cultivars were generally higher in phenolic content and antioxidant activity than CB from modern cultivars. All EB showed increased phenolic content and antioxidant activity compared to CB, but the increase varied with the source flour, despite WSP supplementation was the same for all breads. In particular, the increase in phenolic content was much relevant for EB of modern cultivars.

Genotypic and Organ Variation in Ginsenoside Contents from American Ginseng Populations

Variation in ginsenoside content was investigated as a function of population/genotype, plant organ, and age using four geographically isolated wild populations and one landrace population of american ginseng (Panax quinquefolius L.). The contents of individual and total ginsenosides were affected by the main and two-way interactions between population, organ, and age. Ginsenoside Re was not detected in roots of the wild population plants but was found in leaves and in both organs of the landrace population. A positive relationship between root age and total root ginsenosides was detected in two wild populations. Individual root ginsenosides were highly correlated with certain leaf ginsenosides in wild populations rather than in landrace populations. Therefore, the results suggest that certain leaf ginsenosides would be applied for potential biomarkers to estimate individual root ginsenosides. Principal component analysis (PCA) scores plot indicates that all wild populations were segregated from the single landrace population. However, cluster analysis indicates that differences existed between organs, and between the wild and landrace populations. Overall, the result suggests that the variation of individual and total ginsenoside contents would be influenced by a combination of population, plant organ, and root age.