African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12496

Full Length Research Paper

Synthesis and characterization of interspecific trigenomic hybrids and allohexaploids between three cultivated Brassica allotetraploids and wild species Brassica fruticulosa

Ji-Peng Chen, Xian-Hong Ge, Xing-Cheng Yao, Ye-Hong Feng and Zai-Yun Li*
National Key Laboratory of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement (Wuhan), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
Email: [email protected]

  •  Accepted: 02 May 2011
  •  Published: 28 September 2011

Abstract

 

Interspecific reciprocal crosses between three cultivated Brassica allotetraploidsand one wild species Brassica fruticulosa (FF, 2n =16) were made and the trigenomic hybrids were produced only with embryo rescue. From the crosses withBrassica juncea (AABB, 2n = 36) and Brassica napus (AACC, 2n = 38), hybrids (F.AB, 2n = 26; F.AC, 2n = 27) were obtained only with B. fruticulosa as female, but the reciprocal crosses with Brassica carinata (BBCC, 2n = 34) gave rise to hybrids (F.BC/BC.F, 2n = 25). These hybrids showed an intermediate morphology and were sterile for male and female except those with B. carinata. All the triploids showed high frequency of bivalents during diakinesis and metaphase I (MI) of meiosis. The allohexaploids (FF.AABB, 2= 52; FF.AACC, 2= 54; BBCC.FF, 2= 50) were synthesized by colchicine treatments of respective hybrids in vitro, which showed growth vigor and had larger stature than the hybrids, but were male sterile except one (FF.AABB). They produced progenies with the expected chromosome complements (F.AABB, 2= 44; F.AACC, 2= 46; BBCC.F, 2= 42) after pollination by respective Brassica allotetraploids. In these allohexaploids, chromosomes were mainly paired as bivalents at diakinesis and segregated equally at anaphase I (AI) during meiosis of pollen mother cells (PMCs). These allohexaploids and progenies were valuable for the breeding of Brassica crops.

 

Key words: Brassica allotetraploids, Brassica fruticulosa, interspecific hybrids, crossability, morphology, genomic affinity.

Abbreviation

PMCs, Pollen mother cells; MI, metaphase I; AI/TI, anaphase I/telophase I; GISH, genomic in situ hybridization; DAPI, 4’-6-diamidino-2-phenylindole.