High-yielding NERICA mutant rice for upland areas and hope for Bangladeshi farmers.

Abstract Drought is an important stress phenomenon in Bangladesh that greatly hampers crop production. So, it is imperative to develop drought-tolerant rice varieties. Low-yielding, non-uniform flowering and late-maturing Africa rice - New Rice for Africa (NERICA), viz. NERICA-1, NERICA-4 and NERICA-10 varieties - were irradiated with different doses of gamma-rays (250, 300 and 350 Gy) in 2010. M1 plants were grown and M2 plants were selected based on earliness and higher grain yield. The desired mutants along with other mutants were grown as the M3 generation during 2011. A total of 37 mutants from NERICA-1, NERICA-4 and NERICA-10 were selected on the basis of plant height, short duration, drought tolerance and high yield in the M4 generation. In the M5 generation, six mutants were selected for drought tolerance, earliness, grain quality and higher yield. With respect to days to maturity and grain yield (t/ha), the mutant N1/250/P-2-6-1 of NERICA-1 matured earlier (108 days) and had higher grain yield (5.1 t/ha) than the parent. The mutant N4/350/P-4(5) of NERICA-4 also showed a higher grain yield (6.2 t/ha) than its parent and other mutants. On the other hand, NERICA-10 mutant N10/350/P-5-4 matured earlier and had a higher yield (4.5 t/ha) than its parent. Finally, based on agronomic performance and drought tolerance, the two mutants N4/350/P-4(5) and N10/350/P-5-4 were selected and were evaluated in drought-prone and upland areas during 2016 and 2017. These two mutants performed well with higher grain yield than the released upland rice varieties. They will be released soon for commercial cultivation and are anticipated to play a vital role in food security in Bangladesh.