title: Phylogenetic insight into subgenera Idaeobatus and Malachobatus (Rubus, Rosaceae) inferring from ISH analysis.
abstract: BACKGROUND
  Rubus is a large and taxonomically complex genus exhibiting agamospermy, polyploidy and frequent hybridization. The objective of this work was to elucidate rDNA disrtibution pattern and investigate genomic composition of polyploids in 16 Rubus taxa (2n = 2x, 3x, 4x, 8x) of two subgenera Idaeobatus and Malachobatus by ISH method.
  
  
  RESULTS
  The basic Rubus genome had one 45S rDNA locus, and all the polyploids (except R. setchuenensis) had the expected multiples of this number. Diploid and tetraploid Rubus taxa carried two 5S rDNA, whereas the triploid and octoploid species only had three. The duplicated 45S rDNA sites tended to be conserved, whereas those of 5S rDNA tended to be eliminated after polyploidization. The accession R03-20 was an autotriploid R. parvifolius, while R03-27 and R03-57 were naturally-occurred triploid hybrids between R. parvifolius and R. coreanus. GISH results suggested that R. parvifolius had close relationship with polyploids from Malachobatus.
  
  
  CONCLUSIONS
  The polyploids from Malachobatus were probable allopolyploid. In addition, Rubus parvifolius might be involved in hybridization, polyploidization and speciation of some Idaeobatus and Malachobatus species.
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Yan
authors: Y
authors: Wang
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China ; Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu, 611130 People's Republic of China.
authors: Xiaorong
authors: X
authors: Wang
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Qing
authors: Q
authors: Chen
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Li
authors: L
authors: Zhang
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Haoru
authors: H
authors: Tang
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Ya
authors: Y
authors: Luo
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, 625014 People's Republic of China.
authors: Zejing
authors: Z
authors: Liu
keywords: Allopolyploid; GISH; Hybrid; Rubus; rDNA-FISH