Review

The progress of intersubgenomic heterosis studies in Brassica napus

Li Maoteng^{1, 2}*, Qian Wei³, Chen Xin⁴ and Meng Jinling²

¹College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.

²National Key Laboratory of Crop Improvement, Huazhong Agricultural University, Wuhan 430070, China.

³School of Agronomy and Life Science, South West University, Chongqing 400716, China.

*Corresponding author. E-mail: limaoteng426@163.com.

Accepted 30 December, 2009

   Abstract

The new nomenclature of Brassica has been suggested in a previous study by same authours where the symbols of A^r, A^j and Aⁿ represented the A genome in the Brassica rapa, Brassica juncea and Brassica napus, B^b, B^j and B^c for the B genome of Brassica nigra (black mustard), B. juncea and Brassica carinata, C^o, Cⁿ and C^c for the C genome of Brassica oleracea, B. napus and B. carinata. Numerous efforts have focused on exploring novel B. napus (AⁿAⁿCⁿCⁿ) breeding stocks by the hybridization between Brassica species. Thereafter, most interspecific hybrids in Brassicas could be considered as intersubgenomic hybrids. In this review, examples are shown from recent studies on the method for construction of new-typed B. napus with genome composition of A^rA^rC^cC^c and A^rA^rCⁿCⁿ, the meiosis and embryo sac development of new-typed B. napus, the appearance of intersubgenomic (AⁿA^rCⁿC^c and A^rAⁿCⁿCⁿ) heterosis and the mechanism for production of intersubgenomic heterosis were described.

Key words: New-typed B. napus, subgenome, intersubgenomic heterosis.