Hybrid identification of Cunninghamia lanceolata × Platycladus orientalis based on ISSR markers

Key words: 
• forest tree breeding /
• Cunninghamia lanceolata（Chinese fir） /
• Platycladus orientalis /
• distant hybrids /
• intersimple sequence repeat （ISSR） molecular marker /
• hybrid identification

Abstract: To identify truthfulness of distant hybrids for Cunninghamia lanceolata（Chinese fir） × Platycladus orientalis，a series of exploratory experiments were conducted with 9 intersimple sequence repeat （ISSR） primers having polymorphism screened out from 100 University of British Columbia（UBC） primer Set # 9（800 - 900）. For A4（1419） × B1 distant cross combinations of C. lanceolata × P. orientalis，four outstanding seedlings were selected. Analysis of the parents and the four outstanding seedlings was done with DNA extraction；polymerase chain reaction （PCR） amplification using 9 polymorphism primers；polyacrylamide gel electrophoresis（PAGE） based on the following order of maternal：A4，seedlings （No. 2，3，11， 12），paternal，and ethylene dibromide （EB） staining；and DNA band observations with an ultraviolet lamp. Then，these were recorded with an FR-200A Bio-electrophoresis Image Analysis System. Experimental results of the four outstanding seedlings （No. 2，3，11，12） showed that for the combination of A4 × B1：（1） there were 16 paternal special bands in 7 of the 9 polymorphic primers and（2） there were no paternal special bands with the other 2 primers，but some common bands of their parents were detected within the four seedlings. Thus，（1） all selected outstanding seedlings were distant hybrids；（2） distant hybridization between C. lanceolata × P. orientalis was compatible；and（3） wide cross breeding of Chinese fir could be used for multiple-trait genetic improvement of forest trees. ［Ch，3 fig. 1 tab. 17 ref.］