Increasing the planting density is an effective way to increase the yield of maize (Zea mays L.), although it can also aggravate ovary apical abortion-induced bald tips of the ears, which might, in turn, reduce the yield. While the mechanism underlying the regulation of drought-related abortion in maize is well established, high planting density-related abortion in maize remains poorly understood. Therefore, the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density. This was achieved by evaluating the effects of four different plant densities (60000 plants ha–1 (60 k), 90 k, 120 k, and 150 k) on plant traits related to plant architecture, the plant ear, flowering time, and silk development in two inbred lines (Zheng58 and PH4CV) and two hybrid lines (Zhengdan958 and Xianyu335). The phenotypes of both inbred and hybrid plants were observed under different planting density treatments, and the high planting density was found to increase the phenotypic performance values of the evaluated traits. The anthesis–silking interval (ASI) was extended, and the amount of the silk extruded from husks was reduced upon increasing the planting density. Delayed silk emergence resulted in asynchronous flowering and ear bald tips. Observations of the silk cells revealed that the silk cells became smaller as planting density increased. The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism. These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.

ZHANG Min;XING Li-juan;REN Xiao-tian;ZOU Jun-jie;SONG Fu-peng;WANG Lei;XU Miao-yun

Biotechnology Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081,P.R.China;College of Bioscience and Resources of Environment,Beijing University of Agriculture,Beijing 102206,P.R.China;National Engineering Laboratory for Effcient Utilization of Soil and Fertilizer Resource,College of Resources and Environment,Shandong Agricultural University,Tai'an 271018,P.R.China

农业科学学报（英文）

[1]ZHANG Min;XING Li-juan;REN Xiao-tian;ZOU Jun-jie;SONG Fu-peng;WANG Lei;XU Miao-yun-.Evidence of arrested silk growth in maize at high planting density using phenotypic and transcriptional analyses)[J].农业科学学报（英文）,2022(11):3148-3157

Zheng58,Zhengdan958,Xianyu335,husks

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