Mapping of quantitative trait loci for floral scent compounds in cowpea (<i>Vigna unguiculata</i> L.)

Abstract:
Floral scent is a very important trait in plant evolution. Currently, little is

known about the inheritance of floral scent in cowpea (Vigna unguiculata

L.) or changes that might have occurred during its domestication.

Therefore, we analysed scent volatiles and molecular markers in a population

of 159 F7 recombinant inbred lines derived from a cross of a

domesticated blackeye cowpea cultivar, ‘524B’ and a wild accession

‘219-01’. Using gas chromatography-mass spectrometry (GC–MS) 23

volatile compounds were identified that fall into five general functional

categories. Twenty-two of the compounds displayed quantitative variation

in the progeny, and a total of 63 QTLs influencing the amounts of

these volatiles were mapped onto the cowpea genetic marker map.

Although QTLs for volatile compounds putatively involved in cowpea

flower scent were found on 9 of the 11 cowpea chromosomes, they were

not evenly distributed with QTLs mainly clustered on LGs 1, LGs 2 and

LG 4. Our results serve as a starting point for both more detailed analyses

of complex scent biosynthetic pathways and the development of

markers for marker-assisted breeding of scented rose varieties.