A consortium of Indian scientists identifies a novel mutant of rice which can withstand the use of a commonly used broad spectrum herbicide, Imazethapyr. It will enable development of herbicide-tolerant variety in rice and protect the crops from weeds.
Chennai (ISW): Farmers often use toxic chemicals to destroy unwanted vegetation in their fields but such use can also adversely affect yield of crops. Now Indian scientists have found a way to grow rice crop tolerant to herbicides.
A consortium of scientists led the Tamil Nadu Agricultural University (TNAU), Coimbatore has identified a novel mutant of rice which can withstand the use of a commonly used broad spectrum herbicide, Imazethapyr.
Herbicides act by disrupting key enzymes and proteins involved in essential processes associated with growth and development of plants. Imazethapyr is a popular herbicide but is not traditionally used on rice fields as it adversely affects the yield.
Over the years, many herbicide-tolerant crops, including those resistant to imazethapyr, have been developed but most of them are protected under patents. The mutation identified by the group can be used without restriction in public funded rice breeding.
Scientists used rice variety Nagina 22 in the study since it is already tolerant to heat and drought, and ideally suited for Indian conditions. In this variety, they identified a gene (HTM-N22) and the mutations within it which are responsible for development of tolerance to imazethapyr. This will enable test development for identification of the tolerant variety in rice breeding programmes and protect rice cultivation from weeds. In terms of distinctness, uniformity and stability, the tolerant variety appeared indistinguishable, according to results of the study published in Journal Rice.
The researchers expect HTM-N22 to have an easy process of registration for widespread commercialization since development of this mutant did not require genetic engineering of the rice crop. They believe most significant use of the herbicide-tolerant mutant will be in its usage in publicly-funded rice breeding programmes in India and elsewhere without infringing intellectual property.
The institutions that participated in TNAU-led project were Indian Agricultural Research Institute, National Research Centre on Plant Biotechnology, Punjab Agricultural University, Indian Institute of Rice Research, University of Agricultural Sciences, Bengaluru; National Rice Research Institute, Cuttack; and National Bureau of Plant Genetic Resources, New Delhi.
