Wyman D. Trees for American gardens. New York: Macmillan; 1955.
Höfer M, Mams EA, Sellmann J, Peil A. Phenotypic evaluation and characterization of a collection of Malus species. Genet Resour Crop Evol. 2014;61:943–64.
Lisandru TT, Füstös A, Dumitraş A, Mitre V. Flower development of ornamental crabapple according to BBCH scale. Bulletin UASVM Hortic. 2017;74:147–8.
Muzher BM, Younis RAA, El-Halabi O, Ismail OM. Genetic identification of some Syrian local apple(Malus sp.) cultivars using molecular markers. Res J Agric Biol Sci. 2007;3:704–13.
Ulukan H. The evolution of cultivated plant species: classical plant breeding versus genetic engineering. Plant Syst Evol. 2009;280:133–42.
Brown SK. Apple (Malus × domestica). New York: Springer; 2012.
Mratinić E, Akšić MF. Phenotypic Diversity of apple (Malus sp.) germplasm in south serbia. Braz Arch Biol Technol. 2012;55:349–58.
Fiala JL. Flowering crabapples: the genus Malus. Portland: Timber Press; 1994.
Endress PK. The flowers in extant basal angiosperms and inferences on ancestral flowers. Int J Plant Sci. 2001;162:1111–40.
Maere S, De BS, Raes J, Casneuf T, Van Montagu M, Kuiper M, et al. Modeling gene and genome duplications in eukaryotes. Proc Natl Acad Sci U S A. 2005;102:5454–9.
Becker A, Alix K, Damerval C. The evolution of flower development: current understanding and future challenges. Ann Bot. 2011;107:1427–31.
Armbruster WS. Evolution of floral form: electrostatic forces, pollination, and adaptive compromise. New Phytol. 2001;152:181–3.
Benlloch R, Berbel A, Serranomislata A, Madueño F. Floral initiation and inflorescence architecture: a comparative view. Ann Bot. 2007;100:659–76.
Sargent RD, Goodwillie C, Kalisz S, Ree RH. Phylogenetic evidence for a flower size and number trade-off. Am J Bot. 2007;94:2059–62.
Goodwillie C, Sargent RD, Eckert CG, Elle E, Geber MA, Johnston MO, et al. Correlated evolution of mating system and floral display traits in flowering plants and its implications for the distribution of mating system variation. New Phytol. 2010;185:311–21.
Mojica JP, Kelly JK. Viability selection prior to trait expression is an essential component of natural selection. Proc Biol Sci. 2010;277:2945–50.
Dudash MR, Hassler C, Stevens PM, Fenster CB. Experimental floral and inflorescence trait manipulations affect pollinator preference and function in a hummingbird-pollinated plant. Am J Bot. 2011;98:275–82.
Endress PK. Evolutionary diversification of the flowers in angiosperms. Am J Bot. 2011;98:370–96.
Johnson K, Lenhard M. Genetic control of plant organ growth. New Phytol. 2011;191:319–33.
Coen ES, Meyerowitz EM. The war of the whorls: genetic interactions controlling flower development. Nature. 1991;53:31–7.
Theissen G. Development of floral organ identity: stories from the MADS house. Curr Opin Plant Biol. 2001;4:75–85.
Theissen G, Saedler H. Floral quartets. Nature. 2001;409:469–71.
Li Y, Li Y. Morphological studies on floral organ development of the flowers with single- and Triple-whorled petals in Lisianthus (Eustoma grandiflorum). Acta Hortic Sin. 2005;32:458–62.
Baum DA, Hileman LC. A developmental genetic model for the origin of the flower. In: Ainsworth C, editor. flowering and its manipulation (Annual Plant Reviews, vol. 20). Oxford: Blackwell Publishing Ltd; 2006. p. 1–27.
Hernández-Hernández T, Martínez-Castilla LP, Alvarez-Buylla ER. Functional diversification of B MADS-box homeotic regulators of flower development: Adaptive evolution in protein-protein interaction domains after major gene duplication events. Mol Biol Evol. 2007;24:465–81.
Kramer EM. Understanding the genetic basis of floral diversity. Bioscience. 2007;57:479–87.
Mondragón-Palomino M. Perspectives on MADS-box expression during orchid flower evolution and development. Front Plant Sci. 2013;4:377–85.
Li L, Yu XX, Guo CC, Duan XS, Shan HY, Zhang R, et al. Interactions among proteins of floral MADS‐box genes in Nuphar pumila (Nymphaeaceae) and the most recent common ancestor of extant angiosperms help understand the underlying mechanisms of the origin of the flower. J Syst Evol. 2015;53:285–96.
Bemer M, Angenent GC. Floral organ initiation and development. J R Asiat Soc. 2009;100:29–36.
Reznick DN, Ricklefs RE. Darwin’s bridge between microevolution and macroevolution. Nature. 2009;457:837–42.
Xu B. An overview of macroevolution on the viewpoint of microevolution. Acta Botanica Yunnanica. 1991;13:101–12.
Chu AX. Research on the cultivar classification of ornamental crabapples in Henan. Nanjing: Nanjing Forestry University; 2009.
Liu ZQ, Tang GG. A study on cultivar classification system of Malus halliana Koehne. J Nanjing Forestry Univ. 2004;28:101–6.
Qian GZ. The taxonomic study of the genus Malus Mill. Nanjing: Nanjing Forestry University; 2005.
RHJ S. double flower. In: Basra AS, editor. Encyclopedic Dictionary of Plant Breeding and Related Subjects. New York: Food Products Press; 2003. p. 139.
Nitasaka E. Insertion of an En/Spm-related transposable element into a floral homeotic gene DUPLICATED causes a double flower phenotype in the Japanese morning glory. Plant J. 2003;36:522–31.
Li ZR, Peng Q, Ji ZC, Gao KY, Yi LX, Liao HM, et al. Floral vascular bundle system anatomical observation of double flower Jasminum mesnyi Hance. Hunan Agric Sci. 2016;5:5–7.
Akita Y, Horikawa Y, Kanno A. Comparative analysis of floral MADS-box genes between wild-type and a putative homeotic mutant in lily. J Hortic Sci. 2008;83:453–61.
Akita Y, Nakada M, Kanno A. Effect of the expression level of an AGAMOUS-like gene on the petaloidy of stamens in the double-flowered lily, ‘Elodie’. Sci Hortic. 2011;128:48–53.
Ao Y, Wang Y, Chen L, Wang T, Yu HY, Zhang ZX. Identification and comparative profiling of microRNAs in wild-type Xanthoceras sorbifolia, and its double flower mutant. Genes Genomics. 2012;34:561–8.
Heijmans K, Morel P, Vandenbussche M. MADS-box genes and floral development: the dark side. J Exp Bot. 2012;63:5397–404.
Liu Z, Zhang D, Liu D, Li F, Lu H. Exon skipping of AGAMOUS homolog PrseAG in developing double flowers of Prunus lannesiana (Rosaceae). Plant Cell Rep. 2013;32:227–37.
Noor SH, Ushijima K, Murata A, Yoshida K, Tanabe M, Tanigawa T, et al. Double flower formation induced by silencing of C-class MADS-box genes and its variation among petunia Cultivars. Sci Hortic. 2014;178:1–7.
Sharifi A, Oizumi K, Kubota S, Bagheri A, Shafaroudi SM, Nakano M, et al. Double flower formation in Tricyrtis macranthopsis, is related to low expression of AGAMOUS, ortholog gene. Sci Hortic. 2015;193:337–45.
Zhang H, Ren S. Flora reipublic popularis sinicae. Beijing: Science Press; 1998.
Cheng J. The genetics and breeding of garden plants. Beijing: China Forestry Press; 2001.
Zhu G. The potential role of B-function gene involved in floral development for double flowers formation in Camellia changii Ye. Afr J Biotechnol. 2011;10:541–8.
Galimba KD, Tolkin TR, Sullivan AM, Melzer R, Theißen G, Di Stilio VS. Loss of deeply conserved C-class floral homeotic gene function and C- and E-class protein interaction in a double-flowered ranunculid mutant. Proc Natl Acad Sci U S A. 2012;109:2267–75.
Bouvet JM, Makouanzi G, Cros D, Vigneron PH. Modeling additive and non-additive effects in a hybrid population using genome-wide genotyping: prediction accuracy implications. Heredity. 2016;116:146–57.
Bolormaa S, Pryce JE, Zhang Y, Reverter A, Barendse W, Hayes BJ, et al. Non-additive genetic variation in growth, carcass and fertility traits of beef cattle. Genet Sel. Evol. 2015;47:26.
Fu D, Xiao M, Hayward A, Jiang GJ, Zhu LR, Zhou QH, et al. What is crop heterosis: new insights into an old topic. J Appl Genet. 2015;56:1–13.
Hufford KM, Mazer SJ. Plant ecotypes: genetic differentiation in the age of ecological restoration. Trends Ecol Evol. 2003;18:147–55.
Cheng J, Liu Q. Garden plant genetics and breeding. Beijing: China Forestry Press; 2010.
Gul R, Khalil IH, Shah SMA, Ghafoor A. Heterosis for flower and fruit traits in tomato (Lycopersicon esculentum Mill.). Afr J Biotechnol. 2010;9:4144–51.
Nnungu SI, Uguru MI. Expression of heterosis in floral traits and fruit size in tomato (Solanum lycopersicum) hybrids. J Trop Agric, Food, Environ Ext. 2014;13:24–9.
Ryder P, Mckeown PC, Fort A, Spillane C. Epigenetics and heterosis in crop plants. In: Alvarez-Venegas R, Peña CDL, Casas-Mollano JA, editors. Epigenetics in plants of agronomic importance: fundamentals and applications. Switzerland: Springer International Publishing; 2014. p. 13–31.
Li SC, Li SB, Jiang YL, Yang CM, Wu LF. Genetic performance of primary ornamental traits in F1 hybrids of Gerbera jamesonii bolus intervarietal hybridization varietal hybridization. J Yunnan Agric Univ. 2007;22:197–201.