Drought Tolerant Lines Improved Through Mutation

Good harvest under drought condition is now possible with the development of five breeding lines that can thrive well even with less water in rainfed areas.

Bred by the Philippine Rice Research Institute (PhilRice), the drought-screened (DrS) lines include DrS 1062, DrS 1085, DrS 1061, DrS 1042, and DrS 1057. The lines, which are identified under moderate to severe drought conditions, were developed from NSIC Rc 9 (Apo).

“NSIC Rc 9 is an upland drought tolerant rice variety with poor grain quality. To improve its adaptability to rainfed areas, yield performance, and grain quality, our team conducted series of studies from induced mutation, line traits characterization, drought tolerance screening, and field performance evaluation,” said Jonathan S. Concepcion, science research analyst. Induced mutation is a process that alters the genetic make-up of a plant.

The identified five DrS lines performed well in Nueva Ecija, Iloilo, and Samar with an average yield of 3.978, 3.928, and 3.423 t/ha respectively. These amount of yields are higher than 2.9 t/ha national average of Rc 9.

The research team used In vitro mutagenesis (IVM) to develop these elite mutant breeding lines. IVM is a process of combining tissue culture technique with gamma irradiation, which enhances genetic variation to improve plant traits and quality.

Tissue culture is a process of growth and development of cells derived from living tissues in an artificial medium containing different plant hormones while gamma irradiation is a procedure that uses gamma ray which allows alteration in the genetic make-up through deletion, insertion, or rearrangement.

According to Concepcion, DrS 1057 was identified as the most stable line with wide adaptability across sites.

Grain quality has also improved after mutation technique. The IVM lines have longer, more slender grains, and better eating quality than Rc 9.

Image credit: Gelyn D. Valida for www.philrice.gov.ph
Image credit: Gelyn D. Valida for www.philrice.gov.ph

These lines are also to be used as gene sources for drought tolerance in improving rice varieties for rainfed-ecosystem and multiple-stress tolerance. DrS 1042 has been nominated and evaluated in the National Cooperative Testing for rainfed – direct seeded areas.

In 2016, almost 200,000 local farmers have been affected with drought with 54% rice farmers.

“This will help the farmers get more profit, especially those cultivating in rainfed areas that are often subjected to drought,” Concepcion expressed.

The excellent grain quality made possible by these drought-tolerant lines will mean higher price of milled rice for farmers.

 

Written by Allan Biwang, Jr. in Philrice’s official website. See original article link here.