title: Plant Density Effect on Grain Number and Weight of Two Winter Wheat Cultivars at Different Spikelet and Grain Positions.
abstract: In winter wheat, grain development is asynchronous. The grain number and grain weight vary significantly at different spikelet and grain positions among wheat cultivars grown at different plant densities. In this study, two winter wheat (Triticum aestivum L.) cultivars, 'Wennong6' and 'Jimai20', were grown under four different plant densities for two seasons, in order to study the effect of plant density on the grain number and grain weight at different spikelet and grain positions. The results showed that the effects of spikelet and grain positions on grain weight varied with the grain number of spikelets. In both cultivars, the single-grain weight of the basal and middle two-grain spikelets was higher at the 2nd grain position than that at the 1st grain position, while the opposite occurred in the top two-grain spikelets. In the three-grain spikelets, the distribution of the single-grain weight was different between cultivars. In the four-grain spikelets of Wennong6, the single-grain weight was the highest at the 2nd grain position, followed by the 1st, 3rd, and 4th grain positions. Regardless of the spikelet and grain positions, the single-grain weight was the highest at the 1st and 2nd grain positions and the lowest at the 3rd and 4th grain positions. Overall, plant density affected the yield by controlling the seed-setting characteristics of the tiller spike. Therefore, wheat yield can be increased by decreasing the sterile basal and top spikelets and enhancing the grain weight at the 3rd and 4th grain positions, while maintaining it at the 1st and 2nd grain positions on the spikelet.
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Zhengyong
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Agricultural Bureau of Rencheng District, Jining, Shandong, P. R. China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Ni
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Mengjing
authors.initials: M
authors.lastname: Zheng
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Dongqing
authors.initials: D
authors.lastname: Yang
authors.affiliation: Agricultural Bureau of Zhangqiu District, Jinan, Shandong, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Jin
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Zhenlin
authors.initials: Z
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, Shandong, P. R. China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Yin
mesh_terms: D018533:Biomass; D002523:Edible Grain / Q000254:growth & development*; D018547:Plant Stems / Q000502:physiology; D012621:Seasons; D012639:Seeds / Q000502:physiology; D014908:Triticum / Q000033:anatomy & histology / Q000254:growth & development*