Identification and Validation of a Core Single-Nucleotide Polymorphism Marker Set for Genetic Diversity Assessment, Fingerprinting Identification, and Core Collection Development in Bottle Gourd

Germplasm collections are indispensable resources for the mining of important genes and variety improvement. To preserve and utilize germplasm collections in bottle gourd, we identified and validated a highly informative core single-nucleotide polymorphism (SNP) marker set from 1,100 SNPs. This marker set consisted of 22 uniformly distributed core SNPs with abundant polymorphisms, which were established to have strong representativeness and discriminatory power based on analyses of 206 bottle gourd germplasm collections and a multiparent advanced generation inter-cross (MAGIC) population. The core SNP markers were used to assess genetic diversity and population structure, and to fingerprint important accessions, which could provide an optimized procedure for seed authentication. Furthermore, using the core SNP marker set, we developed an accessible core population of 150 accessions that represents 100% of the genetic variation in bottle gourds. This core population will make an important contribution to the preservation and utilization of bottle gourd germplasm collections, cultivar identification, and marker-assisted breeding.

Genomewide SNP marker identification associated with drought tolerance in oil palm

Yono D, Nugroho YA, Tanjung ZA, Utomo C, Liwang T. 2021. Genomewide SNP marker identification associated with drought tolerance in oil palm. Biodiversitas 22: 3138-3144. Drought stress is one of the abiotic stresses that frequently occurred in the oil palm plantation and has a negative impact on fresh fruit bunch (FFB) production. Therefore, drought-tolerant palms are essential to be selected to mitigate this challenge. In Indonesia, several oil palm plantation areas have a dry climate, such as Lampung province. Distinct yield performance palms were identified from well-recorded agronomic trials in these areas, where the palms are frequently exposed to drought stresses every year and lead them to suffer from water deficit response. Group of high and low-yielding palms was selected based on FFB production of each palm for at least ten constitutive years. The double digest restriction amplified DNA (ddRAD) genotyping methods were used to capture the Single Nucleotide Polymorph (SNP) variant from pools of sample association datasets. At least, 538k SNPs were identified from these pooled datasets. A bulked segregant analysis with a Case-Control approach was implemented to screen the contrast SNP profiles between both pools. A total of 56 association signals was selected from sequential filtering. These SNP sites are located in 21 genes. Further SNP validation and phenotypic verification are necessary to obtain SNPs marker for drought-tolerant palm selections.

Development of Single Nucleotide Polymorphism (SNP) Markers in Tropical Crops

Understanding genetic diversity, association studies, evolution analysis, quantitative trait loci, marker-assisted selection and genome-wide association in tropical crops are important for improving plant characteristics in order to increase food sustainability in tropical countries. Single nucleotide polymorphism (SNP) marker is becoming the most popular molecular marker for those studies. By using SNP marker, genes associated with important traits can be identified efficiently compared to the other molecular markers. This review describes about how SNP can be discovered in the plant genomes and the application of SNP in plant breeding, especially in tropical crops such as rice, maize, peas, potato, tomato, cassava, taro, etc. Keywords: food sustainability, plant breeding, SNP marker, tropical crops

Identification, gene expression and genetic polymorphism of zinc finger A20/AN1 stress-associated genes, HvSAP, in salt stressed barley from Kazakhstan

Background A family of genes designated as the Zinc finger A20/AN1 Transcription factors encoding stress-associated proteins (SAP) are well described in Arabidopsis and rice, and include 14 AtSAP and 18 OsSAP genes that are associated with variable tolerances to multiple abiotic stresses. The SAP gene family displays a great diversity in its structure and across different plant species. The aim of this study was to identify all HvSAP genes in barley (Hordeum vulgare L.), to analyse the expression of selected genes in response to salinity in barley leaves and develop SNP marker for HvSAP12 to evaluate the association between genotypes of barley plants and their grain yield in field trials. Results In our study, 17 HvSAP genes were identified in barley, which were strongly homologous to rice genes. Five genes, HvSAP5, HvSAP6, HvSAP11, HvSAP12 and HvSAP15, were found to be highly expressed in leaves of barley plants in response to salt stress in hydroponics compared to controls, using both semi-quantitative RT-PCR and qPCR analyses. The Amplifluor-like SNP marker KATU-B30 was developed and used for HvSAP12 genotyping. A strong association (R2 = 0.85) was found between KATU-B30 and grain yield production per plant of 50 F3 breeding lines originating from the cross Granal × Baisheshek in field trials with drought and low to moderate salinity in Northern and Central Kazakhstan. Conclusions A group of HvSAP genes, and HvSAP12 in particular, play an important role in the tolerance of barley plants to salinity and drought, and is associated with higher grain yield in field trials. Marker-assisted selection with SNP marker KATU-B30 can be applied in barley breeding to improve grain yield production under conditions of abiotic stress.

Conservation Status and Historical Relatedness of South African Communal Indigenous Goat Populations Using Genome-Wide Snp Marker

Background: Indigenous goats forms the majority of populations in smallholder; low input, low output production systems and are considered an important genetic resource due to their adaptability to different production environments and support communal farming. Effective population size (Ne), inbreeding levels, and the runs of homozygosity (ROHs) are effective tools for exploring the genetic diversity and understanding the demographic history in efforts to support breeding strategies to use and conserve genetic resources. Results: Across populations, the current Ne of Gauteng was the lowest at 371 animals, while the historical Ne across populations suggests that the ancestor Ne has decreased by 53.86%, 44.58%, 42.16% and 41.16% in Free State (FS), North West (NW), Limpopo (LP) and Gauteng (GP), respectively, over the last 971 generations. Genomic inbreeding levels related to ancient kinship (FROH >5Mb) was highest in FS (0.08±0.09) and lowest for Eastern Cape (EC) (0.02±0.02). A total of 871 ROH island regions which include important environmental adaptation and hermo-tolerance genes such as IL10RB, IL23A, FGF9, IGF1, EGR1, MTOR and MAPK3 were identified (occurring in over 20% of the samples) in FS (n = 37), GP (n = 42), NW (n = 2) populations only. The mean length of ROH across populations was 7.76Mb and ranged from 1.61Mb KwaZulu-Natal (KZN) to 98.05Mb (GP and NW). Distribution of ROH according to their size showed that the majority (n = 1949) of the detected ROH were >5Mb in length than the other categories. Assuming two hypothetical ancestral populations, the population from KZN and LP are revealed, supporting PC 1. The genomes of KZN and LP shared an origin but have substantial admixture from the EC and NW populations.Conclusions: These findings indicated a greater negative impact of inbreeding in recent times which is important for planning conservation strategies. It was revealed that the occurrence of high Ne and autozygosity varied largely across breeds in communal indigenous goat populations at different recent and ancient events when a genome-wide SNP marker was used.

SNP marker association for incrementing soybean seed protein content

Soybean seed protein content (SPC) has been decreasing throughout last decades and DNA marker association has shown its usefulness to improve this trait even in soybean breeding programs that focus primarily on soybean yield and seed oil content (SOC). Aiming to elucidate the association of two SNP markers (ss715630650 and ss715636852) to the SPC, a soybean population of 264 F5-derived recombinant inbred lines (RILs) from a bi-parental cross was tested in four environments. Through the single-marker analysis, the additive effect () and the portion of SPC variation due to the SNPs () for single and multi-environment data were assessed, and transgressive RILs for SPC were observed. The estimates revealed the association of both markers to SPC in most of environments. The marker ss715636852 was more frequently associated to SPC, including multi-environment data, and contributed up to = 1.30% for overall SPC, whereas ss715630650 had significant association just in two locations, with contributions of = 0.76% and = 0.74% to overall SPC in Vic1 and Cap1, respectively. The RIL 84-13 was classified as an elite genotype due to its favorable alleles and high SPC means, which reached 53.78% in Cap1, and 46.33% in MET analysis. Thus, these results confirm the usefulness of the SNP marker ss715636852 in a soybean breeding program for SPC.