National Organic Standards Board 

Materials Subcommittee 

Excluded Methods Discussion Document 

Plant Breeding Techniques “TBD List” 

February 14, 2023 

Summary of Request: 

The Materials Subcommittee is seeking feedback on the remaining To Be Determined (TBD) List in the 

Excluded Methods Plant Breeding Techniques discussion document. The goal is to determine whether 

the techniques are excluded methods under the legal definition at 205.2, OFPA criteria, as well as 

previous NOSB recommendations. . The Materials Subcommittee has requested a limited scope TR for 

induced mutagenesis in order to facilitate the work and has included questions for stakeholder feedback 

in this discussion document. 

Summary of Review: 

Draft Definitions 

TILLING (Targeted Induced Local Lesions in Genomes): 

This technique has two parts: 

First, mutations are induced in seeds by treating them with mutagenic chemicals, or, less commonly, 

using environmental stresses or radiation. These provide an increased frequency of point mutations 

distributed randomly in the genome. In Eco-TILLING, mutagens are not used. Genetic diversity is 

obtained by using diverse seed sources. 

Second, samples are taken from seedlings grown out from step one, and tested to find those with 

mutations in a targeted location within the plant genome. Desired seedlings can then be used for 

breeding. 

Double Haploid (DH): 

Double haploid is a genotype of two identical chromosomes from spontaneous or artificial doubling, 

which produces pure homozygous or inbred lines. This greatly expedites breeding procedures, slimming 

a 5-or-6-year task to only one generation. To date, maize is the predominant crop bred using this 

technique. 

There are two methods to produce DH plants. In-vivo and in-vitro with the use of synthetic chemicals to 

double chromosomes. 

Firstly, in-vivo methods accomplish double haploidy with cross pollination techniques using irradiated 

pollen or haploid inductor or inducer lines. Megaspores/ovule cells can be induced with pollen of the 

inductor lines to develop haploid embryos without recombination of genes. The haploid embryo can 

spontaneously double its chromosomes to become homozygous double haploid plants. Double haploidy 

can be obtained all in-vivo. 

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Secondly, in-vitro methods are plant tissue cultures (often times treated with phytohormones to 

stimulate growth) of haploid cells from either microspores/pollen in androgenesis or megaspores/ovules 

in gynogenesis which differentiate into haploid embryos then haploid plants. These haploid plants will 

duplicate their chromosomes spontaneously or with the application of colchicine, a synthetic chemical 

resulting in a homozygous double haploid plant. 

Induced Mutagenesis: 

Mutagenesis is a process by which the genetic information of an organism is changed by the production 

of a mutation(a). The agents that cause mutation are called mutagens(b). Mutation induced by mutagens 

is called induced mutation. 

a

In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an 

organism, virus, or extrachromosomal DNA) 

b

In genetics, a mutagen is a physical or chemical agent that permanently changes genetic 

material, usually DNA, in an organism and thus increases the frequency of mutations above the 

natural background level. 

Mutagenesis may occur spontaneously in nature, or as a result of exposure to mutagens. It can also be 

achieved experimentally using laboratory procedures. A mutagen is a mutation-causing agent, be it 

chemical or physical, which results in an increased rate of mutations in an organism's genetic code. In 

nature mutagenesis can lead to cancer and various heritable diseases, and it is also a driving force 

of evolution. 

Transposons: 

A chromosomal segment that can undergo transposition, especially a segment of bacterial DNA that can 

be translocated as a whole between chromosomal, phage, and plasmid DNA in the absence of a 

complementary sequence in the host DNA. Also called jumping gene. 

A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can 

change its position within a genome, sometimes creating or reversing mutations and altering the cell's 

genetic identity and genome-size. 

Questions: 

1. Please provide feedback on the draft definitions along with relevant peer reviewed scientific sources. 

2. In the use of each technique, please describe the individual steps and the application of prohibited 

substances or excluded methods that may be employed in that step towards creating new varieties of 

plants or animals, if applicable. 

3. For each technique, describe/list plant varieties, clones, etc. which may have been developed and are 

currently being used in organic systems. 

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To Be Determined “TBD list”: 

Terminology 

Method and 

synonyms 

Types Excluded 

Methods 

Criteria 

Used 

Notes 

TILLING Eco-TILLING TBD Stands for “Targeted 

Induced Local Lesions in 

Genomes.” Standard 

TILLING includes induced 

mutagenesis. Eco-TILLING 

does not. 

Doubled Haploid 

Technology (DHT) 

TBD There are several ways to 

make double haploids, 

and some do not involve 

genetic engineering while 

some do. It is difficult or 

impossible to detect DHT 

with tests. 

Induced 

Mutagenesis 

TBD Induced mutagenesis 

developed through 

exposure to UV light, 

chemicals, irradiation or 

other stress. 

Transposons TBD Produced from chemicals, 

ultraviolet radiation, or 

other synthetic activities. 

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Excluded Methods: 

Method and 

synonyms 

Types Excluded 

Methods 

Criteria 

Applied 

Notes 

Targeted genetic 

modification 

(TagMo) syn. 

Synthetic gene 

technologies syn. 

Genome engineering 

syn. 

Gene editing syn. 

Gene targeting 

Sequence-specific nucleases 

(SSNs) 

Meganucleases Zinc finger 

nuclease (ZFN) 

Mutagenesis via 

Oligonucleotides 

CRISPR-Cas system (Clustered 

regularly interspaced short 

palindromic repeats) and 

associated protein genes 

TALENs (Transcription 

activator-like effector 

nucleases) 

Oligonucleotide directed 

mutagenesis 

(ODM) Rapid Trait 

Development System 

YES 1, 3, 4 Most of these new 

techniques are not 

regulated by USDA and are 

currently difficult to 

determine through testing. 

Gene Silencing RNA-dependent DNA 

methylation (RdDM) Silencing 

via RNAi pathway RNAi 

pesticides 

YES 1, 2, 4 

Accelerated plant 

breeding techniques 

Reverse Breeding 

Genome Elimination 

FasTrack 

Fast flowering 

YES 1, 2, 4 These may pose an 

enforcement problem for 

organics because they are 

not detectable in tests. 

Synthetic Biology Creating new DNA sequences 

Synthetic chromosomes 

Engineered biological functions 

and systems 

YES 1, 3, 4 

Cloned animals and 

offspring 

Somatic nuclear transfer YES 1, 3 

Plastid 

transformation 

YES 1, 3, 4 

Cisgenesis The gene modification of a 

recipient plant with a natural 

gene from a crossable-sexually 

compatible-plant. The 

introduced gene includes its 

introns and is flanked by its 

native promoter and 

terminator in the normal-sense 

orientation. 

YES 1, 3, 4 Even though the genetic 

manipulation may be 

within the same species, 

this method of gene 

insertion can create 

characteristics that are not 

possible within that 

individual with natural 

processes; it can have 

unintended consequences. 

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Method and 

synonyms 

Types Excluded 

Methods 

Criteria 

Applied 

Notes 

Intragenesis The full or partial coding of DNA 

sequences of genes originating 

from the sexually compatible 

gene pool of the recipient plant 

and arranged in sense or 

antisense orientation. In 

addition, the promoter, spacer, 

and terminator may originate 

from a sexually compatible 

gene pool of the recipient 

plant. 

YES 1, 3, 4 Even though the genetic 

manipulation may be 

within the same species, 

this method of gene 

rearrangement can create 

characteristics that are not 

possible within that 

individual with natural 

processes; it can have 

unintended consequences. 

Agro-infiltration YES 1, 3, 4 In vitro nucleic acids are 

introduced to plant leaves 

to be infiltrated into them. 

The resulting plants could 

not have been achieved 

through natural processes 

and are a manipulation of 

the genetic code within the 

nucleus of the organism. 

TransposonsDeveloped via use of 

in vitro nucleic acid 

techniques 

YES 1,3,4 Does not include 

transposons developed 

through environmental 

stress such as heat, 

drought or cold. 

Induced 

Mutagenesis 

YES 1 Developed through in vitro 

nucleic acid techniques 

does not include 

mutagenesis developed 

through exposure to UV 

light, chemicals, irradiation, 

or other stress-causing 

activities. 

Cell and Protoplast 

Fusion 

Donor and/or recipient cells are 

outside taxonomic plant family; 

and/or recombinant DNA 

technology is employed 

YES Terms 

Defined 

205.2 

See NOP 

Policy Memo 13-1. 

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Methods Allowed: 

Method and 

synonyms 

Types Excluded 

Methods 

Criteria 

Applied 

Notes 

Marker Assisted 

Selection 

NO 

Transduction NO 

Embryo rescue in 

plants 

NO IFOAM’s 2018 position 

paper on Techniques in 

Organic Systems considers 

this technique compatible 

with organic systems. 

Embryo transfer, or 

embryo rescue, in 

animals 

NO *use of hormones not 

allowed in recipient 

animals. 

Transposons NO Developed through 

environmental stress, such 

as heat, drought, or cold. 

Cell and Protoplast 

Fusion 

Recipient and/or donor cells are 

within the same taxonomic 

plant family; must be achieved 

without recombinant DNA 

technology 

NO NOP Policy Memo 13-1; 

Definition of Modern 

Biotechnology 

Subcommittee Vote: 

Motion to accept the discussion document on excluded methods TBD List 

Motion by: Mindee Jeffery 

Seconded by: Brian Caldwell 

Yes: 5 No: 0 Abstain: 0 Recuse: 0 Absent: 1 

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