Chen Xian-Min, Li Feng-Yuan, Dong Shuai, Liu Xin-Fang, Li Bin-Bin, Xiao Zu-Dong, Deng Tao, Wang Yan-Bo, Shen Si, Zhou Shun-Li
College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
Corn Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, China.
Front Plant Sci. 2022 Jun 13;13:901186. doi: 10.3389/fpls.2022.901186. eCollection 2022.
Ear architecture is determined by two stable heritable traits, kernel row number (KRN) and kernel number per row (KNPR), but its relationship with drought resistance is still vague. To this end, we obtained 16 and 11 hybrids with slender (less KRN but more KNPR) and stubby (more KRN but less KNPR) ears by intentionally crossbreeding, respectively. These hybrids were exposed to a seven-day water deficit (WD) since silk emergence coupled with synchronous (SP) and continuous pollination (CP) to alter the pollination time gaps on ears. The results showed that the emerged silks in CP were 9.1 and 9.0% less than in the SP treatment in the stubby and slender ears, respectively, suggesting the suppression of asynchronous pollination on silk emergence. The stubby ears performed higher silking rate and yield compared with the slender ears with or without drought stress. To eliminate the inherent difference in sink capacities, we selected four hybrids for each ear type with similar silk and kernel numbers for further analyses. Interestingly, the stubby ears were less affected in silking rate and thus performed higher yield under drought compared with the slender ears. The finding suggests that ear architecture matters in the determination of drought resistance that deserves more attention in breeding.
穗型由两个稳定的可遗传性状决定，即穗行数（KRN）和每行粒数（KNPR），但其与抗旱性的关系仍不明确。为此，我们分别通过有意杂交获得了16个和11个具有细长穗（穗行数少但每行粒数多）和粗短穗（穗行数多但每行粒数少）的杂交种。这些杂交种在吐丝后暴露于7天水分亏缺（WD）条件下，并进行同步授粉（SP）和连续授粉（CP），以改变穗上的授粉时间间隔。结果表明，粗短穗和细长穗中CP处理的吐丝量分别比SP处理少9.1%和9.0%，这表明异步授粉对吐丝有抑制作用。无论有无干旱胁迫，粗短穗的吐丝率和产量均高于细长穗。为消除库容量的内在差异，我们为每种穗型选择了4个吐丝量和粒数相似的杂交种进行进一步分析。有趣的是，与细长穗相比，粗短穗的吐丝率受影响较小，因此在干旱条件下产量更高。这一发现表明，穗型在抗旱性的决定中起重要作用，在育种中值得更多关注。
