For the first time, 2 new genome-edited rice varieties: Why is this such a major breakthrough for ICAR and India’s agriculture?

Which are these two genome-edited varieties of rice?

These have been named ‘Kamala’ and ‘Pusa DST Rice 1’. They have better stress tolerance, improved yields, and climate adaptability without any compromises with their existing strengths.

DRR DHAN 100 (KAMALA): Developed by the ICAR-Indian Institute of Rice Research (ICAR-IIRR), Hyderabad, this variety promises significantly higher yields, improved drought tolerance, and early maturity compared to its parent variety, Samba Mahsuri (BPT 5204).

According to the ICAR, DRR Dhan 100 (Kamala) has been developed using genome editing technology targeting the Cytokinin Oxidase 2 (CKX2) gene (also known as Gn1a), to increase grain numbers per panicle.

“Using the Site Directed Nuclease 1 (SDN1) genome editing approach, ICAR-IIRR scientists introduced precise mutations without incorporating any foreign DNA. The resulting mutant line demonstrated superior yield performance, drought tolerance, high nitrogen-use efficiency, and maturity ~20 days earlier (around 130 days) than its parent variety,” the Council said in a statement.

“The new genome-edited line, officially designated IET 32072, was evaluated in multi-location field trials during 2023 and 2024 under the All India Coordinated Research Project on Rice (AICRPR). Results showed a 19% yield improvement over Samba Mahsuri, with DRR Dhan 100 (Kamala) recording an average yield of 5.37 tonnes per hectare, compared to 4.5 tonnes per hectare for its parent. Under optimal conditions, DRR Dhan 100 (Kamala) has demonstrated a yield potential of up to 9 tons per hectare,” it said.

The ICAR release pointed out that DRR Dhan 100 (Kamala) retains the grain and cooking quality that makes Samba Mahsuri a consumer favourite.

Workers transplanting paddy crop. (Express file photo by Nirmal Harindran)

It said that the Kamala variety has been recommended for cultivation across major rice-growing states, including Andhra Pradesh, Telangana, Karnataka, Tamil Nadu, Puducherry, Kerala (Zone VII), Chhattisgarh, Maharashtra, Madhya Pradesh (Zone V), Odisha, Jharkhand, Bihar, Uttar Pradesh, and West Bengal (Zone III).

PUSA DST RICE 1: This new genome-edited variety has been developed over the widely cultivated fine-grain variety called MTU1010 by ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi.

Developed through Site Directed Nuclease 1 (SDN1) genome-editing, the new variety, Pusa DST Rice 1, targets the Drought and Salt Tolerance (DST) gene to improve the plant’s resilience to harsh soil and climate conditions.

“The genome-edited line contains no foreign DNA, making it comparable to conventionally bred varieties,” ICAR said. The new variety was field-tested under the AICRPR during 2023 and 2024, and demonstrated “remarkable improvements in yield performance under various stress conditions”.

The new variety is relevant for farmers of saline and alkaline soils, where traditional varieties underperform.

* According to the ICAR, Pusa DST Rice 1 recorded a yield of 3,508 kg per hectare in inland salinity, which is 9.666 per cent higher than its parent variety, MTU 1010’s yield (3,199 kg/ha).

* In alkaline soils, Pusa DST Rice 1 recorded a yield of 3,731 kg/ha, which was 14.66 per higher as compared to MTU1010 variety (3,254 kg/ha).

* And in coastal salinity, ‘Pusa DST Rice 1’ performance was even better. ‘Pusa DST Rice 1’ recorded a yield of 2,493 kg/ha in coastal salinity, which was 30.4 per cent higher than MTU 1010 (1,912 kg/ha).

This variety of rice has been recommended for cultivation across key rice-growing states, including Andhra Pradesh, Telangana, Karnataka, Tamil Nadu, Puducherry, Kerala (Zone VII), Chhattisgarh, Maharashtra, Madhya Pradesh (Zone V), Odisha, Jharkhand, Bihar, Uttar Pradesh, and West Bengal (Zone III).

But what specific practical benefits will derive from cultivating these two new varieties?

BIGGER YIELDS, LESS EMISSIONS: According to ICAR, cultivation of DRR Dhan 100 (Kamala) and Pusa DST Rice 1 varieties in about 5 million hectares of the recommended area will produce 4.5 million tonnes of additional paddy, and a reduction of greenhouse gas emissions by 20% (32,000 tonnes).

LESS WATER CONSUMPTION: “…Due to shorter duration of Kamala, three irrigations will be saved resulting in saving of a total of 7,500 million cubic metres of irrigation water, which can be used for other crops,” the ICAR statement said.

So are these varieties safe, and have they received all clearances required for cultivation?

The ICAR scientists have used the revolutionary CRISPR-Cas9 genome-editing technology, which won the Nobel Prize in Chemistry in 2020, to develop these two varieties.

This technology enables scientists to make targeted changes in the native genes of living organisms, creating new and desirable traits without introducing foreign DNA.

“Two key approaches — Site Directed Nuclease 1 (SDN1) and Site Directed Nuclease 2 (SDN2) — produce genetically edited organisms that are considered indistinguishable from naturally occurring or conventionally bred mutants. As such, they are exempt from the stringent biosafety regulations under Rules 7-11 of the Environment (Protection) Act, 1986,” according to ICAR.

The Council said that the Institutional Biosafety Committees (IBC) of respective ICAR institutes had approved the lines, and the Review Committee on Genetic Manipulation (RCGM) had granted clearance on May 31, 2023 for their classification under India’s relaxed regulatory framework for SDN1 and SDN2 genome edits.

Therefore, these two varieties have received “appropriate biosafety clearance” under India’s simplified regulations for genome-edited crops. Some concerns about the Intellectual Property Rights of the technology exist, but they are being “looked after and will be resolved in times to come”, ICAR said.

Why is this breakthrough in paddy so significant?

Paddy is India’s principal crop of the kharif season, and is grown on one-third of the entire area under all foodgrain crops. It contributes about 40% to the country’s foodgrain basket, and is critical to the nation’s food security.

West Bengal, Uttar Pradesh, Punjab, Odisha, Andhra Pradesh, Telangana, Tamil Nadu, Chhattisgarh, Bihar and Assam are the main paddy growing states.

As per the Agriculture Ministry, paddy (kharif and rabi together) accounted for 45 million hectares of area, which was the highest in the world in 2020. However, in terms of production, India (186.5 million tonnes) ranked second after China (211 million tonnes). The reason is the lower yield in India. India’s paddy yield (4,138 kg/ha) was lower than the world’s average of 4,717 kg/ha, China’s (7,043 kg/ha), Indonesia’s (5,128 kg/ha) and Bangladesh’s (4,809 kg/ha).

Is India developing other genome-edited varieties of crops as well?

Yes, research programmes on genome-editing have been initiated for other crops including oilseeds and pulses as well, officials said. The government has allocated Rs 500 crore for genome-editing in agricultural crops, and the University of Delhi has developed a genome-edited variety of mustard.