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Leafy heads of cabbage (Brassica oleracea), Chinese cabbage (Brassica rapa), and lettuce (Lactuca sativa) are composed of extremely incurved leaves. The shape of these heads often dictates the quality, and thus the commercial value, of these crops. Using quantitative trait locus mapping of head traits within a population of 150 recombinant inbred lines of Chinese cabbage, we investigated the relationship between expression levels of microRNA-targeted Brassica rapa ssp. pekinensis TEOSINTE BRANCHED1, cycloidea, and PCF transcription factor4 (BrpTCP4) genes and head shape. Here, we demonstrate that a cylindrical head shape is associated with relatively low BrpTCP4-1 expression, whereas a round head shape is associated with high BrpTCP4-1 expression. In the round-type Chinese cabbage, microRNA319 (miR319) accumulation and BrpTCP4-1 expression decrease from the apical to central regions of leaves. Overexpression of BrpMIR319a2 reduced the expression levels of BrpTCP4 and resulted in an even distribution of BrpTCP4 transcripts within all leaf regions. Changes in temporal and spatial patterns of BrpTCP4 expression appear to be associated with excess growth of both apical and interveinal regions, straightened leaf tips, and a transition from the round to the cylindrical head shape. These results suggest that the miR319a-targeted BrpTCP gene regulates the round shape of leafy heads via differential cell division arrest in leaf regions. Therefore, the manipulation of miR319a and BrpTCP4 genes is a potentially important tool for use in the genetic improvement of head shape in these crops.Chinese cabbage (Brassica rapa), cabbage (Brassica oleracea), and lettuce (Lactuca sativa) have uniform, tightly formed heads composed of yellow-green, crinkly leaves. These leaves serve as an important source of mineral nutrients, crude fiber, and vitamins in the human diet. Head shape can vary depending on the cultivar; the two most common shapes are round and cylindrical, with others often being oblong or cone like. Chinese cabbage is commonly sold by head shape and color rather than by individual varieties. The favorable shape often changes according to current consumer preference.

Two kinds of twinning morphologies of ZnO crystallites prepared under hydrothermal conditions were obtained. The twin relations of the crystallites could be influenced by additives. The twinned crystallites in the pure H2O or weak basic solutions (1 N KOH) are bipyramidal and take (0001‐) as the twin and composition plane, whereas the twinning morphology of the crystallites obtained from 4 N KBr or 3 N NaNO2 solutions is dumbbell‐like and takes (0001) as the composition plane. Various twinning mechanisms based on the linkage of the growth units are suggested. The formation of twin morphologies of ZnO crystallites clearly demonstrate that twinning of crystals is either a result of differences between symmetrical and energetic most favourable structure arrangements or due to the consequence of oriented intergrowths.