This study was initiated to identify quantitative trait loci (QTL) involved in root system development by measuring root length and weight of rice seedlings grown in hydroponic culture condition. Growth conditions for estimating the root elongation were set up to supply NH₄⁺ as a single nitrogen source. Four rice accessions and 40 introgression lines (ILs) derived from a cross between ‘Ilpumbyeo’, a temperate japonica variety, and ‘Moroberekan’, a tropical japonica accession, were used to detect QTL for two root traits of seedlings grown in 0, 250 and 500 μM NH₄⁺. Seven chromosomal regions were found to be involved in root elongation. The qRW6 QTL detected on the long-arm of chromosome 6 promoted root weight and the ‘Moroberekan’ allele at this QTL was associated with enhanced root weight at 250 μM NH₄⁺ concentration. The Moroberekan alleles were beneficial at all loci except for qRW4 at which the Ilpumbyeo allele increased root weight under 0, 250 and 500 μM NH₄⁺. A field trial was conducted for selected four ILs to know whether the introgressed Moroberekan segments harboring the beneficial QTL were associated with effects on other agronomic traits. No significant difference was detected between four ILs and Ilpumbyeo for days to heading and culm length. Two lines showed significant difference from Ilpumbyeo in spikelets per panicle and 1,000 grain weight, and the difference might be attributed to the Moroberekan segment on chromosome 6. Our QTL results indicate that the Moroberekan introgression on chromosome 6 flanked by RM162-RM3430 has the potential to enhance root traits and yield potential in the temperate japonica background.

Citations

Citations to this article as recorded by  

• Identification of shoot and root genomic regions in response to nitrogen deficiency tolerance in rice through the use of rice back cross recombinant inbred lines (BRILs)
  Abdul Malik Solangi, Hira Khanzada, Ghulam Mustafa Wassan, Adnan Rasheed, Ayaz Ali Keerio, Huijie Li, Saba Khanzada, Muhammad Faheem, Mashooq Ali Laghari, Jianmin Bian, Xiaohua Pan, Ziming Wu
  Journal of Plant Biochemistry and Biotechnology.2023; 32(1): 40.     CrossRef
• Genome-wide association study and transcriptome analysis reveal new QTL and candidate genes for nitrogen‐deficiency tolerance in rice
  Qing Li, Xueli Lu, Changjian Wang, Lan Shen, Liping Dai, Jinli He, Long Yang, Peiyuan Li, Yifeng Hong, Qiang Zhang, Guojun Dong, Jiang Hu, Guangheng Zhang, Deyong Ren, Zhenyu Gao, Longbiao Guo, Qian Qian, Li Zhu, Dali Zeng
  The Crop Journal.2022; 10(4): 942.     CrossRef
• Pinpointing genomic regions associated with root system architecture in rice through an integrative meta-analysis approach
  Parisa Daryani, Hadi Darzi Ramandi, Sara Dezhsetan, Raheleh Mirdar Mansuri, Ghasem Hosseini Salekdeh, Zahra-Sadat Shobbar
  Theoretical and Applied Genetics.2022; 135(1): 81.     CrossRef
• Mapping of quantitative trait loci for root elongation in rice ( Oryza sativa L.) treated with various nitrogen sources and concentrations
  Kazuhiro Sasaki, Mitsuhiro Obara
  Soil Science and Plant Nutrition.2022; 68(4): 454.     CrossRef
• Root Branching and Nutrient Efficiency: Status and Way Forward in Root and Tuber Crops
  Luis O. Duque, Arthur Villordon
  Frontiers in Plant Science.2019;[Epub]     CrossRef
• RDWN6XB, a major quantitative trait locus positively enhances root system architecture under nitrogen deficiency in rice
  Galal Bakr Anis, Yingxin Zhang, Anowerul Islam, Yue Zhang, Yongrun Cao, Weixun Wu, Liyong Cao, Shihua Cheng
  BMC Plant Biology.2019;[Epub]     CrossRef

Although traditional rice varieties and wild rice species exhibit vast genetic diversity, the transfer of useful genes to modern varieties is often hampered by linkage drag. In this study, the previously identified blast resistance locus Pi45(t) from a cross between ‘Ilpumbyeo’ and ‘Moroberekan’ was linked to the spreading-type panicle caused by the SPR3 locus. Using InDel4 and RM17579 linked to the Pi45(t) and the SPR3, respectively, the distance between the two loci was estimated to be 6.9cM. This suggests a tight, yet incomplete linkage and provides the opportunity to utilize Pi45(t) in breeding programs without including SPR3. Two groups based on the genotype at the SPR3 locus were assembled; the CLosed Panicle (CLP) and SPReading panicle (SPR) groups, with lines which were homozygous for the Ilpumbyeo and Moroberekan alleles, respectively. A comparison between the traits of CLP and SPR groups revealed a decrease in 1000-grain weight and length and an increase in spikelets per panicle and secondary branches in the SPR group. This complicates selection against SPR3 as it is not clear whether these quantitative trait loci are linked to either SPR3 or Pi45(t). Re-evaluation of these traits using lines recombinant at the two loci would be necessary to clarify this issue.

Citations

Citations to this article as recorded by  

• Directional upgrading of brown planthopper resistance in an elite rice cultivar by precise introgression of two resistance genes using genomics-based breeding
  Hongbo Wang, Yi Gao, Fangming Mao, Lizhong Xiong, Tongmin Mou
  Plant Science.2019; 288: 110211.     CrossRef