You have reached the IRRI Genebank, where your rice science journey begins. Home to more than 132,000 available accessions which includes cultivated species, wild relatives and species from related genera.

Descriptor: Chromosome number (chno)

Chromosomes is the DNA-containing linear bodies found in the cell nuclei of plants responsible for the determination and transmissions of hereditary characters. - Number is recorded at post-harvest. - Observed in wild species.
Post-harvest Stage
Crop Germplasm Committee approved
Data Type:
Numeric descriptor
Maximum Length:
Responsible Site:
International Rice Research Institute (IRRI)

Studies or environments

Distribution of Values for Chromosome number (chno)

RangeNumber of Accessions
24.00000 - 26.400002270
26.40000 - 28.800000
28.80000 - 31.200000
31.20000 - 33.600000
33.60000 - 36.000000
36.00000 - 38.400000
38.40000 - 40.800000
40.80000 - 43.200000
43.20000 - 45.600000
45.60000 - 48.00000146

International Rice Genebank Germplasm Distribution and Exchange Policy

IRRI continues the free international exchange of germplasm, in accordance with the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA). We provide rice in small quantities to any entity or establishment for research, breeding, or training for food and agriculture purposes; free of charge. At the same time, we gratefully receive seed contributions to add to our collection.

The procedure for acquiring seeds from IRRI are as follows:
1. Read, study and comply with Standard Material Transfer Agreement(SMTA).
2. Inquire, search and choose accessions through GRIN-Global or Genesys websites.
3. Submit requests electronically through the public websites (refer to #2)