An international team of scientists were able to identify candidate
genesfor further genetic research on the improvement of root phenotypes
to respond todroughtstress by examining the phenotypic and genetic
correlations among rice root anatomical, morphological, and agronomic
phenotypes.

The team used more than 200 riceaccessions from Southeast Asia for their
study to identify root morphological and anatomical phenotypes related
to rice productivity under stress. Data showed that drought stress is a
result of the slight increases in the basal metaxylem and stele diameter
of rice nodal roots. The scientists also found that biomass was
consistently positively related to crown root number, but negatively to
stele diameter. Further probing using the genome-wide association study
helped identify 59 candidate genes related to root development.
Particularly, the OsRSL3 gene in four SNPs was found to cause amino acid
changes and are significantly associated with root phenotype.

The study showed that detailed genetic analysis can help identify and
explain phenotypic relationships through SNP effects on various rice
phenotypes. The scientists plan to do further research using an elite
pool of drought breeding rice lines to assess the benefits of an elite
background that can be used for further testing and validation.

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