Marker Assisted Development and Characterization of Herbicide Tolerant Near Isogenic Lines of a Mega Basmati Rice Variety, “Pusa Basmati 1121”

Abstract

Background Direct-seeded rice (DSR) is a potential technology for sustainable rice farming as it saves water and labor. However, higher incidence of weed under DSR limits productivity. Therefore, there is a need to develop herbicide tolerant (HT) rice varieties. Results We used marker assisted backcross breeding (MABB) to transfer a mutant allele of Acetohydroxy acid synthase (AHAS) gene, which confers tolerance to imidazolinone group of herbicides from the donor parent (DP) “Robin” into the genetic background of an elite popular Basmati rice variety, Pusa Basmati 1121 (PB 1121). Foreground selection was done using the AHAS gene linked Simple Sequence Repeat (SSR) marker RM6844 and background selection was performed using 112 genome-wide SSR markers polymorphic between PB 1121 and Robin. Phenotypic selection for agronomic, Basmati grain and cooking quality traits in each generation was carried out to improve the recovery of recurrent parent phenome (RPP). Finally, a set of 12 BC4F4 near isogenic lines (NILs), with recurrent parent genome (RPG) recovery ranging from 98.66 to 99.55% were developed and evaluated. PB 1121-HT NILs namely 1979-14-7-33-99-10, 1979-14-7-33-99-15 and 1979-14-7-33-99-66 were found superior to PB 1121 in yield with comparable grain and cooking quality traits and herbicide tolerance similar to Robin. Conclusion Overall, the present study reports successful development of HT NILs in the genetic background of popular Basmati rice variety, PB 1121 by introgression of mutated AHAS allele. This is the first report on the development of HT Basmati rice. Superior NILs are being evaluated in the national Basmati trials, the release of which is likely to provide a viable option for the adoption of DSR technology in Basmati rice cultivation.

Molecular Breeding for Improving Productivity of Oryza sativa L. cv. Pusa 44 under Reproductive Stage Drought Stress through Introgression of a Major QTL, qDTY12.1

“…This has been a conspicuous deviation from our earlier approaches wherein background selection was augmented with phenotypic selection to ensure better RPG as well as recurrent parent phenome (RPP) recovery [ 34 , 35 , 36 ]. Ultimately, deferred background selection provided a recovery of 94.7–98.7%, closely similar to the level of recovery that was previously reported [ 37 , 38 ]. This provided us with two advantages: (i) considerable time could be saved on screening the background markers, which helped us to shuttle the breeding materials between New Delhi and Aduthurai in time, and (ii) considerable resources could be saved as the background recovery was tested on a small panel of selected lines at BC 3 F 4 .…”

Marker-assisted transfer of leaf and stripe rust resistance from Triticum turgidum var. durum cv. Trinakria to wheat variety HD2932

“…Phenotypic selection coupled with marker-assisted background selection resulted in rapid and higher recovery of HD2932 background than the expected average recovery percentage of each backcross generation. The efficacy of phenotypic plus background selection in achieving higher genome recovery with two backcrosses only has been demonstrated in major crops like rice ( Ellur et al, 2016 ; Grover et al, 2020 ), wheat ( Xu et al, 2017 ; Sharma et al, 2021 ; Mallick et al, 2022 ), and maize ( Hossain et al, 2018 ; Zunjare et al, 2018 ).…”

Exploring alternatives for assessing and improving herbicide use in intensive agroecosystems of South Asia: A review

“…For these crops, instead of using higher doses, a tank mix application with other herbicides is advised (Schütte et al, 2017). In India, the recently released HT rice cultivars Pusa 1979 and Pusa 1985 have been developed using markerassisted backcross breeding which is tolerant to the imidazolinone group of herbicides through introgression of mutated acetohydroxy acid synthase (AHAS) alleles (Grover et al, 2020). Herbicide tolerance has been conferred against imidazolinones in several other crops, popularly known as Clearfield crops.…”