2010 Fiscal Year Final Research Report

Cytological and genetic clarification of paternal inheritance of chloroplast genome in Rhododendron.

Research Project

Project/Area Number	20580020
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Horticulture/Landscape architecture
Research Institution	University of the Ryukyus
Principal Investigator	URESHINO Kenji University of the Ryukyus, 農学部, 准教授 (10333759)
Project Period (FY)	2008 – 2010
Keywords	花卉 / ツツジ / ptDNA
Research Abstract	The genetic factor controlling the mode of plastid DNA (ptDNA) inheritance in Rhododendron was investigated using polymerase chain reaction?single-stranded conformation polymorphism analysis at the trnL?trnF intergeneric region. When the reciprocal cross between R. kaempferi var. macrogemma (MCR) (F type) and R. transiens (TRA) (S type) was conducted, a high frequency of paternal ptDNA inheritance was observed in S × F and a low frequency of paternal ptDNA was observed in the reverse cross, as reported previously. When F1 plants from the cross between MCR and TRA were used as seed parents and crossed with R. simsii (SIM) (another F-type species), the pattern of ptDNA inheritance was segregated into 3 types : maternal》 paternal〓biparental, maternal〓paternal》 biparental, and maternal 《paternal》 biparental. This segregation occurred among the cross combinations even though the seed parents and MCR had identical ptDNA. From these results, we conclude that the mode of ptDNA inheritance is controlled mainly by the maternal nuclear gene(s).