Zhang Shuqin, Wang Xinmin, Wang Hongbo, Zou Jun, Dai Lu, Deng Haodong, Jiang Wanxia, Tan Lubin, Liu Fengxia
Frontiers Science Center for Molecular Design Breeding (MOE), Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193 China.
Mol Breed. 2025 Apr 7;45(4):41. doi: 10.1007/s11032-025-01564-2. eCollection 2025 Apr.
Root is an important tissue to absorb water and nutrients from soil in plant and root architecture is one of critical traits influencing grain yield in crop. However, the genetic basis of root architecture remains unclear. In the present study, we identified a wild rice () introgression line Ra33 with longer seedling root length compared with the recipient parent 9311, an variety. Observation of longitudinal sections of root showed that the meristem length of Ra33 was significantly longer than that of 9311. Using an F secondary segregating population derived from a cross between introgression line Ra33 and the recipient parent 9311, we detected a major QTL for root length at early seedling stage, , between the molecular markers M3 and M5 on chromosome 1, and the . -derived allele at increased root length under the background of 9311. In addition, the near-isogenic line NIL- showed a significant increase in root length compared with the recipient parent 9311, further demonstrating the genetic effect of . And then, a total of 159 recombinant individuals were screened from 3355 F individuals and the QTL was narrowed down to an approximate 78 kb interval between markers M4 and RM3, including 12 predicted genes. Further sequence comparison and expression analysis of the predicted genes in the fine-mapping region indicated that eight genes might be the interesting candidates of . The findings will provide new clues to reveal the genetic basis of root length and genetic resources for root architecture improvement in rice.
The online version contains supplementary material available at 10.1007/s11032-025-01564-2.
根是植物从土壤中吸收水分和养分的重要组织，根系结构是影响作物产量的关键性状之一。然而，根系结构的遗传基础仍不清楚。在本研究中，我们鉴定出一个野生稻渗入系Ra33，其幼苗根长比受体亲本9311（一个籼稻品种）更长。对根的纵切片观察表明，Ra33的分生组织长度显著长于9311。利用从渗入系Ra33与受体亲本9311杂交产生的F2次级分离群体，我们在第1染色体上分子标记M3和M5之间检测到一个控制幼苗早期根长的主效QTL，即qRL1-1，其加性效应值为1.37。在9311背景下，qRL1-1位点上来自野生稻的等位基因增加了根长。此外，近等基因系NIL-qRL1-1与受体亲本9311相比，根长显著增加，进一步证明了qRL1-1的遗传效应。然后，从3355个F2个体中筛选出159个重组个体，将QTL qRL1-1定位到标记M4和RM3之间约78 kb的区间内，该区间包含12个预测基因。对精细定位区域内预测基因的进一步序列比较和表达分析表明，8个基因可能是qRL1-1的候选基因。这些发现将为揭示水稻根长的遗传基础提供新线索，并为改良水稻根系结构提供遗传资源。
在线版本包含可在10.1007/s11032-025-01564-2获取的补充材料。
