Mishra Ankita, Barik Saumya Ranjan, Lenka Devidutta, Pandit Elssa, Behera Lambodar, Dash Sushanta Kumar, Sangeeta Sushree, Das Swarnalata, Pradhan Sharat Kumar
College of Agriculture, OUAT, Bhubaneswar, 751003, Odisha, India.
ICAR-Central Rice Research Institute, Cuttack, 753006, Odisha, India.
Sci Rep. 2025 Jul 14;15(1):25418. doi: 10.1038/s41598-025-10951-w.
Rice suffers from drought stress due to its shallow roots, hindering water uptake from deeper soil layers. Transfer of deeper rooting QTL will modify the root architecture of the plant allowing it to extract moisture from deeper layers of the soil. Furthermore, poor soil conditions, particularly phosphorus deficiency is a common problem in the rainfed rice ecology of India which requires adequate phosphate fertilizer for obtaining higher yield. In this current investigation, two QTL (DRO1 and DRO3) for deeper rooting and one QTL for phosphorus uptake (Pup1) were introgressed into a popular variety, 'Maudamani' through marker-assisted backcross breeding. The target QTL were transferred from a pre-breed genotype, CR3996-19-9-45-1 into the popular variety. Foreground selection was performed using the tightly linked microsatellite markers in the backcross generations progenies to select plants carrying the target QTL. Background selection in each backcross generations was performed using 123 polymorphic SSR markers spread across twelve chromosomes. In each backcross generations, plants carrying all three target QTL and with highest recurrent parent genome recovery percentage was used to backcross with the popular variety, Maudamani. In BCF generation, five plants (CR6508-111-101-129, CR6508-111-101-267, CR6508-111-101-413, CR6508-111-101-537 and CR6508-111-101-713) were selected which were homozygous for all three target QTL. The pyramided lines were evaluated for deeper rooting, low phosphorus stress tolerance and various agro-morphologic including quality traits. Progenies of those five pyramided plants showed similarity with the recipient parent for the 14 agro-morphologic and quality traits in their BCF and BCF generations. The introgressed lines demonstrated significantly improved root traits, including increased number of deeper roots, longer root length and higher shoot and root dry weight, compared to Maudamani under both moisture-deficit and normal conditions. Furthermore, those lines exhibited enhanced phosphorus uptake and grain yield compared to the recipient parent, Maudamani under low phosphorus conditions.
水稻因根系浅而遭受干旱胁迫，这阻碍了其从更深土层吸收水分。导入深根QTL将改变植株的根系结构，使其能够从更深土层吸收水分。此外，土壤条件差，尤其是缺磷，是印度雨养水稻生态系统中的常见问题，需要施用足够的磷肥才能获得更高产量。在本次研究中，通过标记辅助回交育种，将两个控制深根的QTL（DRO1和DRO3）和一个控制磷吸收的QTL（Pup1）导入一个 popular 品种‘Maudamani’。目标QTL从一个预育种基因型CR3996 - 19 - 9 - 45 - 1导入到 popular 品种中。在回交后代中使用紧密连锁的微卫星标记进行前景选择，以选择携带目标QTL的植株。在每个回交世代中，使用分布在12条染色体上的123个多态性SSR标记进行背景选择。在每个回交世代中，选择携带所有三个目标QTL且轮回亲本基因组恢复率最高的植株与 popular 品种Maudamani回交。在BCF代中，选择了五株（CR6508 - 111 - 101 - 129、CR6508 - 111 - 101 - 267、CR6508 - 111 - 101 - 413、CR6508 - 111 - 101 - 537和CR6508 - 111 - 101 - 713）对所有三个目标QTL均纯合的植株。对聚合系进行深根、低磷胁迫耐受性以及包括品质性状在内的各种农艺形态学评估。这五株聚合植株的后代在BCF和BCF代的14个农艺形态学和品质性状上与受体亲本表现出相似性。与Maudamani相比，在水分亏缺和正常条件下，导入系的根系性状显著改善，包括深根数量增加、根长更长以及地上部和根部干重更高。此外，在低磷条件下，这些品系与受体亲本Maudamani相比，磷吸收和籽粒产量有所提高。
