The genomes of 2 members of the basmati rice group, a variety of basmati rice, called Basmati 334 and the sadri rice variety Dom Sufid, have been sequenced and analysed. Scientists from New York University, Oxford Nanopore Technologies, and the New York Genome Center sequenced the genomes of the two basmati rice varieties using nanopore sequencing technology, according to a report in February 2020.
The team’s results were published in the journal Genome Biology.
The researchers focused on Basmati 334 from Pakistan, known to be drought tolerant and resistant to rice-killing bacterial blight, and Dom Sufid from Iran, an aromatic long-grain rice that is one of the most expensive on the market. Using long reads from nanopore sequencing, the scientists assembled high-quality, complete genomes of Basmati 334 and Dom Sufid that were a significant improvement over earlier genome sequences assembled using short reads.
By having the sequence of rice varieties like Basmati 334, which can withstand drought conditions and resist bacterial blight, scientists can try to understand their constituents that give rise to these valuable traits. Drought tolerance is of particular interest, in the context of challenges faced due to climate change and the implications for food security worldwide.
The sequencing has confirmed that basmati rice is a hybrid of two rice groups. Most genetic material in basmati comes from japonica, followed by the rice group aus.
The Asian rice (Oryza sativa) is an agriculturally important crop that feeds one-half of the world’s population and is said to supply one-fifth of the caloric intake of people worldwide. Historically, the species has been divided into two major variety groups, japonica and indica, with respect to morphometric differences and molecular markers. These variety groups show the presence of reproductive barriers between them. Analsysis of archaeobotanical remains seems to indicate that japonica rice was domesticated some thousands of years ago in the Yangtze basin of China, while indica rice originated later when domestication alleles were introduced from japonica into either Oryza nivara or a proto-indica in the Indian subcontinent.
More recently, two additional variety groups have been recognised that are genetically distinct from japonica and indica: the aus/circum-aus and aromatic/circum-basmati rice. Among its members, the circum-basmati group boasts the iconic basmati rice from southern Asia and the sadri rice from Iran. Despite its economic and cultural importance, a high-quality reference genome is currently lacking, and the group’s evolutionary history is not fully resolved.
Rice is one of the most important staple crops worldwide, and the varieties in the basmati group are some of the most iconic and prized rice varieties. However, until recently, a high-quality reference genome for basmati rice did not exist.
The next step is to work with the scientific and rice breeding communities to identify important genes, see what makes the basmati group unique, and perhaps develop molecular markers to help breed new varieties.