AN OBJECTIVE METHOD OF PHENOTYPING POD FRAGRANCE IN DOLICHOS BEAN (Lablab purpureus L. SWEET) VAR. LIGNOSUS

H.R. UDAYKUMAR¹*, M. BYREGOWDA², S. RAMESH³, M. VASUNDHARA^4
1Department of Genetics and Plant Breeding, University of Agricultural Sciences (UAS), Bengaluru, Karnataka, India
²All India Coordinated Research Project on Pigeon pea, UAS, Bengaluru, Karnataka, India
³Department of Genetics and Plant Breeding, University of Agricultural Sciences (UAS), Bengaluru, Karnataka, India
⁴Department of Horticulture, UAS, Bengaluru, Karnataka, India
* Corresponding Author : udayhr7096@gmail.com

Received : 06-06-2016     Accepted : 16-06-2016     Published : 03-10-2016
Volume : 8     Issue : 43       Pages : 1867 - 1869
Int J Agr Sci 8.43 (2016):1867-1869

Keywords : Fatty acids, Pod fragrance, Trans-2-dodecenoic acid, Trans-2-tetradecenoic acid
Academic Editor : Dr. Mahadevaiah C
Conflict of Interest : None declared
Acknowledgements/Funding : The senior author acknowledges Kirk House Trust support in the form of fellowship for pursuing PhD thesis research.
Author Contribution : None declared

In dolichos bean, pods with high fragrance fetch premium price in the market. Pod fragrance is routinely assessed through organoleptic means. Phenotyping pod fragrance by organoleptic (smelling) means is highly relative and subjective. Efficiency of breeding dolichos bean varieties with high pod fragrance hinges on an objective method of phenotyping fragrance in breeding populations. An attempt was made to devise an objective assessment of pod fragrance by quantifying the key fatty acids (FA) responsible for pod fragrance. Exudates were collected from the pods of HA-4 (released variety with high pod fragrance) and CPI-31113 (a germplasm accession with lack of pod fragrance). After esterification, the exudates were subjected for gas chromatographic mass spectrometry (GC-MS) analysis to identify the differences between HA 4 and CPI 31113 for key FA responsible for fragrance. The HA 4 pod exudates predominantly consisted of 24.58% trans-2-dodecenoic acid, 17.43% trans-tetradecanoic acid and 3.11% trans-2-tetradecenoic acid. Contrastingly, CPI 31113 pod exudates had 13.77% trans-2-dodecenoic acid and 12.92% of trans-2-tetradecenoic acid. The results indicated appreciable differences in the concentration of trans-2-dodecenoic acid and trans-2-tetradecenoic acids between fragrant variety HA-4 and non-fragrant germplasm accession CPI-31113. Quantifying these two FA in the pod exudates serve as a reliable and an objective method compared to organoleptic means for phenotyping pod fragrance in dolichos bean.