Reverse genetics is a powerful tool for functional genomics study. Chemical mutagenesis efficiently generates phenotypic variations in otherwise homogeneous genetic backgrounds, enabling linking biological function with a gene of interest. Using ethyl methanesulfonate (EMS), we mutagenized the fresh pollen from maize B73 inbred and obtained a large number of mutants. Exome capture-Based SNP Discovery (EBSD) was used to identify all mutated loci. A website, called Maize EMS induced Mutant Database (MEMD), is constructed to allow scientists to search for and order the mutant seeds of interest for non-profit research. We will keep updating all the information related to the mutants.

To better use the maize EMS resource, please read 'About MEMD' in the Help menu carefully.

Please cite: Lu X., Liu J., Ren W., Yang Q., Chai Z., Chen R., Wang L., Zhao J., Lang Z., Wang H., Fan Y., Zhao J., and Zhang C. (2018). Gene-Indexed Mutations in Maize. Mol. Plant. 11, 496-504.

Seed Ordering Procedure:

1. Send an email with detailed information of the mutant lines of your interest as attached Excel file to For convienence, you just need to download and fill in the following blank Excel file.

Blank Mutant Infor Table

2. We will check the seed status and give a response in a week.

3. If the seeds are available, we will inform you to sign a Material Transfer Agreement (MTA), which can be downloaded from the website. If not, we will reproduce the seeds within half a year. MTA should be signed by the PI in your group and the head of your institution.

4. We provide 20 M3-generation seeds for each mutant of a single gene.

5. Because we have not got any national funding during the construction of our maize mutant library and we need lots of money to maintain the library, a handling fee of US $300 or 2000 RMB per mutation is charged.

Note: Please be kindly advised that we are NOT responsible for ensuring a 100% accuracy of a mutation of your interest.


A total of 1,630 EMS mutants newly sequenced were added, and 5,894 lines in total were available now. (2019-12-09)

Except for these four types, i.e., splice_site_donor/acceptor, stop_gained/lost, start_gained:ATG/start_lost, all the mutation types, which may alter the protein function, but not necessarily obvious, are charged 200 RMB. The delivery fee is paid by the users and data about the mutation site determination and phenotype should be send to us. (2019-9-30)

A total of 2322 EMS mutants were newly sequenced, and 4264 lines were available now. (2019-09-19)

Searching mutants by gene name and chromosome range is available now. (2019-04-21)

Please note that we have updated the mutant IDs of 1942 lines to make them consistant with those in maizeGDB.(2017-12-06)