Introgression of qDTY1.1 Governing Reproductive Stage Drought Tolerance into an Elite Basmati Rice Variety “Pusa Basmati 1” through Marker Assisted Backcross Breeding

Abstract

Drought stress at the reproductive stage in rice is one of the most important cause for yield reduction, affecting both productivity and quality. All Basmati rice varieties, including the popular cultivar “Pusa Basmati 1 (PB1)” is highly sensitive to reproductive stage drought stress (RSDS). We report for the first time, improvement of a Basmati cultivar for RSDS tolerance, with the introgression of a major quantitative trait locus (QTL), “qDTY1.1” into PB1. The QTL was sourced from an aus variety, Nagina 22 (N22). A microsatellite (simple sequence repeat (SSR)) marker “RM 431” located at telomeric end (38.89 mb) of chromosome 1, and located within a 1.04 mb QTL region was employed for foreground selection for qDTY1.1 in the marker assisted backcross breeding process. A set of 113 SSR markers polymorphic between N22 and PB1 were utilized for background selection to ensure higher recurrent parent genome recovery. After three backcrosses followed by five generations of selfing, eighteen near isogenic lines (NILs) were developed, through combinatory selection for agro-morphological, grain and cooking quality traits. The NILs were evaluated for three consecutive Kharif seasons, 2017, 2018 and 2019 under well-watered and drought stress conditions. RSDS tolerance and yield stability indicated that P1882-12-111-3, P1882-12-111-5, P1882-12-111-6, P1882-12-111-7, P1882-12-111-12, P1882-12-111-15 and P1882-12-111-17 were best in terms of overall agronomic and grain quality under RSDS. Additionally, NILs exhibited high yield potential under normal condition as well. The RSDS tolerant Basmati NILs with high resilience to water stress, is a valuable resource for sustaining Basmati rice production under water limiting production environments.

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

“…However, a slight reduction in grain dimensions was noticed among the NILs, similarly to the reduction noticed in Pusa 44. A similar reduction in grain dimensions was noticed by Dhawan et al [ 39 ] among the Pusa Basmati 1 qDTY1.1 NILs. Desired grain quality in the selected NILs would facilitate their ready adoption by farmers who are already familiar with the grain quality of Pusa 44, augmented by the potential of yielding well under RSDS.…”

“…Evaluated for two years during the Kharif seasons of 2018 and 2019, the NILs showed significant yield reduction under drought stress when compared to yields under unstressed, irrigated conditions. A similar reduction in yield under imposed drought conditions was reported among the qDTY introgressed NILs of mega cultivars such as Pusa Basmati 1 [ 39 ] and Pusa 44 [ 15 , 16 ]. However, the level of yield reduction was significantly lower among the NILs, with 6.5 times higher yields than those with the recurrent parent, Pusa 44.…”

SA-Mediated Regulation and Control of Abiotic Stress Tolerance in Rice

“…Studies have shown that there is a correlation between ortho-hydroxy-cinnamic (oHCA) and SA indicating that in rice SA production is likely through oHCA and not chorismate pathway. It is believed that the chorismate pathway produced basic SA levels compared to the higher levels seen in rice [ 52 , 53 ].…”

“…Polyamines (PA) were reported to play a role in responding to stresses in plants. While SA levels did not change much in stress, PA levels were however elevated in environmental stress [ 53 ]. This, however, showed that SA and PA are not correlated.…”

Genetic diversity for drought and low-phosphorus tolerance in rice (Oryza sativa L.) varieties and donors adapted to rainfed drought-prone ecologies

“…The DTY QTLs have a genetic gain of 10–30%, with a yield advantage of 150–500 kg ha −1 under reproductive stage moisture stress 16 . Therefore, improvement of rice yield under drought targeted through pyramiding genetically compatible major DTY QTLs in the background of popular rice varieties 6 , 17 – 21 . For the breeders, only the QTLs that express in a range of genetic backgrounds and environments are of interest and can be deployed widely for developing drought tolerant rice varieties.…”