Li Zhi, Luo Qinyi, Deng Yawen, Du Ke, Li Xinli, Ren Tianheng
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China.
College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
Int J Mol Sci. 2023 Sep 19;24(18):14289. doi: 10.3390/ijms241814289.
A recombinant inbred line population including 371 lines was developed by a high kernel number per spike (KNPS) genotype T1208 and a low KNPS genotype Chuannong18 (CN18). A genetic linkage map consisting of 11,583 markers was constructed by the Wheat55K SNP Array. The quantitative trait loci (QTLs) related to KNPS were detected in three years. Eight, twenty-seven, and four QTLs were identified using the ICIM-BIP, ICIM-MET, and ICIM-EPI methods, respectively. One QTL, , which was mapped on chromosome 2D, can explain 18.10% of the phenotypic variation (PVE) on average and be considered a major and stable QTL for KNPS. This QTL was located in a 0.89 Mb interval on chromosome 2D and flanked by the markers and . Moreover, , a Kompetitive Allele-Specific PCR (KASP) marker which closely linked to , was designed. The genetic effect of on KNPS was successfully confirmed in two RIL populations. The results also showed that the significant increase of KNPS and 1000-kernel weight (TKW) was caused by overcoming the disadvantage due to the decrease of spike number (SN) and finally lead to a significant increase of grain yield. In addition, within the interval in which is located in Chinese Spring reference genomes, only fifteen genes were found, and two genes that might associate with KNPS were identified. may provide a new resource for the high-yield breeding of wheat in the future.
以每穗粒数（KNPS）高的基因型T1208和每穗粒数低的基因型川农18（CN18）构建了包含371个株系的重组自交系群体。利用小麦55K SNP芯片构建了由11583个标记组成的遗传连锁图谱。连续三年检测与每穗粒数相关的数量性状位点（QTL）。分别使用ICIM-BIP、ICIM-MET和ICIM-EPI方法鉴定出8个、27个和4个QTL。其中一个位于2D染色体上的QTL，平均可解释18.10%的表型变异（PVE），可被视为每穗粒数的一个主要且稳定的QTL。该QTL位于2D染色体上0.89 Mb的区间内，两侧标记为 和 。此外，设计了一个与 紧密连锁的竞争性等位基因特异性PCR（KASP）标记 。 在两个重组自交系群体中成功验证了其对每穗粒数的遗传效应。结果还表明， 克服了穗数（SN）下降带来的不利影响，显著提高了每穗粒数和千粒重（TKW），最终导致籽粒产量显著增加。此外，在中国春参考基因组中 所在的区间内，仅发现了15个基因，鉴定出两个可能与每穗粒数相关的基因。 可能为未来小麦高产育种提供新的资源。
