Overview
ISO/TR 17623:2015 provides standardized methods for molecular biomarker analysis using Simple Sequence Repeat (SSR) markers in maize. This technical report defines validated SSR markers and protocols specifically designed for applications including hybrid conformity testing, molecular fingerprinting of maize varieties, and confirming variety identity. Developed by ISO Technical Committee ISO/TC 34/Subcommittee SC 16, this document ensures reproducible and reliable SSR analysis results applicable across laboratories worldwide.
The report covers key procedural steps such as sample preparation, DNA extraction, PCR amplification, and product detection using capillary electrophoresis. The SSR markers featured in this report have undergone rigorous intra-laboratory validation at GEVES (France) and are publicly available through maize genomic databases.
Key Topics
-
SSR Marker Characteristics and Validation
The document lists 36 SSR markers with detailed information on allele size ranges, allele diversity (Nei’s index), and primer sequences optimized for maize genomic analysis.
-
Molecular Analysis Workflow
- Sample preparation through grinding individual or mixed seeds
- DNA extraction with protocols validated alongside commercially available kits like QIAGEN DNeasy®
- PCR amplification using simplex PCR with detailed reagent concentrations and conditions, including a touchdown program for optimal primer annealing
- Separation and detection of polymorphic PCR products by capillary electrophoresis with fluorescence detection
-
Hybrid Conformity and Variety Identification
SSR analysis provides high-resolution molecular fingerprints to confirm the genetic identity of maize hybrids and varieties, supporting quality control and breeding programs.
-
SSR Profiles Across Maize Lines
Example molecular profiles for 10 maize lines illustrate allele variations and polymorphisms, enabling reliable distinction between maize varieties based on SSR genetic markers.
Applications
ISO/TR 17623:2015 is practically valuable in:
-
Seed Quality Control
Molecular testing according to this standard enhances the accuracy of hybrid conformity checks, preventing mislabeling or mixing of different maize varieties.
-
Breeding and Genetic Research
Breeders employ SSR markers to track genetic variability and assist in selection processes tailored to specific agronomic traits.
-
Variety Registration and Protection
Ensuring variety identity through SSR fingerprinting facilitates plant breeder rights enforcement and supports seed certification authorities.
-
Laboratory Method Standardization
Standardized PCR conditions, DNA extraction approaches, and SSR marker sets promote consistency for molecular biometric laboratories globally.
Related Standards
-
ISO 13495 – Provides a framework for method validation including acceptance criteria, complementary to SSR marker analysis protocols in ISO/TR 17623:2015.
-
ISO/TC 34/SC 16 Standards – Focus on horizontal molecular biomarker analysis methods for various agricultural products.
-
MaizeGDB Database (www.maizegdb.org) – Public repository of maize SSR marker sequences and additional genomic resources referenced by this report.
Using ISO/TR 17623:2015 ensures precise, reproducible SSR molecular analyses for maize, supporting the agricultural industry in variety verification, seed quality assurance, and genetic characterization aligned with internationally recognized best practices.