Li Yanling, Li Xin, Du Dezhi, Ma Qianru, Zhao Zhi, Wang Long, Zhang Yongshun, Shi Huiqin, Zhao Hongping, Li Huaxin, Pei Damei, Zhao Zhigang, Tang Guoyong, Liu Haidong, Li Haojie, Xiao Lu
Laboratory for Research and Utilization of Qinghai-Tibet Plateau Germplasm Resources, Qinghai Spring Rape Engineering Research Center, Qinghai Research Branch of the National Oil Crop Genetic Improvement Center, Spring Rape Scientific Observation Experimental Station of Ministry of Agriculture and Rural Areas, Academy of Agricultural and Forestry Sciences, Qinghai University, Xining, 810016, Qinghai, China.
Qinghai Key Laboratory of Hulless Barley Genetics and Breeding, Xining, 810016, China.
Theor Appl Genet. 2025 Mar 12;138(4):70. doi: 10.1007/s00122-025-04845-8.
qFT.A02-1, a major quantitative trait locus controlling flowering time in Brassica napus, was mapped to a 104.8-kb region on chromosome A02, and BnaA02G0156900ZS is the candidate gene in response for flowering time. Flowering time is a key agronomic trait that determines the adaptability of crops to the environment and thus affects yields. The mechanism underlying flowering time is still far from clear in Brassica napus. In this study, a recombinant inbred line population composed of 215 lines was constructed and 35 flowering time QTLs were identified. One major QTL, qFT.A02-1 (explaining 16.40-17.80% of phenotypic variation), was detected in two environments, which was confirmed by QTL-seq. A residual heterozygous line containing qFT.A02-1 for flowering time was further constructed, and qFT.A02-1 was subsequently fine-mapped to a 104.8-kb interval, wherein a total of 11 genes were predicted. Candidate gene functional annotation implied that BnaA02G0156900ZS, a homologous gene of FLOWERING LOCUS T in B. napus, was likely the candidate gene for qFT.A02-1. HiFi sequencing of the two parents was subsequently conducted, and a 1,079-bp insertion in the promoter of BnaA02. FT was confirmed. The allelic variation analysis in a diversity of accessions identified another 6 SNPs existing in the non-coding region of BnaA02. FT and the 1,079-bp insertion in promoter region are closely associated with the flowering time in B. napus. Haplotype analysis indicated that the flowering time of Hap02 is significantly earlier than Hap01 and Hap04, and Hap05 is significantly earlier than Hap04. Yield-related trait analysis revealed that there are no significant differences in yield-related traits between the two near-isogenic lines based on the target locus. These results may advance our understanding of the mechanism underlying flowering time in B. napus.
qFT.A02 - 1是控制甘蓝型油菜开花时间的一个主要数量性状位点，被定位到A02染色体上一个104.8 kb的区域，BnaA02G0156900ZS是响应开花时间的候选基因。开花时间是一个关键的农艺性状，它决定了作物对环境的适应性，从而影响产量。甘蓝型油菜开花时间的潜在机制仍远未明确。在本研究中，构建了一个由215个株系组成的重组自交系群体，并鉴定出35个开花时间QTL。在两个环境中检测到一个主要QTL，qFT.A02 - 1（解释了16.40 - 17.80%的表型变异），通过QTL-seq得到了证实。进一步构建了一个含有qFT.A02 - 1开花时间剩余杂合系，随后将qFT.A02 - 1精细定位到一个104.8 kb的区间，其中共预测到11个基因。候选基因功能注释表明，BnaA02G0156900ZS是甘蓝型油菜中FLOWERING LOCUS T的同源基因，可能是qFT.A02 - 1的候选基因。随后对两个亲本进行了HiFi测序，证实了BnaA02. FT启动子中有一个1079 bp的插入。对多个种质的等位变异分析确定了BnaA02. FT非编码区存在另外6个SNP，启动子区域的1079 bp插入与甘蓝型油菜的开花时间密切相关。单倍型分析表明，Hap02的开花时间显著早于Hap01和Hap04，Hap05显著早于Hap04。产量相关性状分析表明，基于目标位点的两个近等基因系在产量相关性状上没有显著差异。这些结果可能会增进我们对甘蓝型油菜开花时间潜在机制的理解。
