Genetic resource enhancement by isolation of diversegenotypes from seed progeny in predominantly sterile rose scentedgeranium Pelargonium graveolens

Abstract

Four new accessions (BSP1-4) of rose scented geranium Pelargonium graveolens were derived from the spontaneous half-sib seed progeny of mostly sterile populations of the cultivar accession Bipuli. The seed producing plants of Bipuli had been growing among the populations of cultivar accessions Hemanti and Kunti in the temperate agroclimate of Kodaikanal, Tamilnadu in India. The four new accessions were compared with the cultivar accessions Bipuli, Hemanti and Kunti in field experiments under subtropical agroclimate of Lucknow, Uttar Pradeshfor essential oil yield and quality related traits and in terms of their RAPD profiles. The crop yield and essential oil parameters and DNA profiles of the four new accessions and three cultivar accessions allowed the conclusion that the accessions BSP-1, BSP-2 and BSP-3 were Bipuli × Kunti hybrids and BSP-4 was a Bipuli × Hemanti hybrid. The accession BSP-4 demonstrated hybrid vigour in several of the essential oil yield related traits; on average basis it out yielded other accessions by afactor of about 2.4. The essential oil of BSP-4 had 89% rhodinol content in which citronellol to geraniol ratio was 1:1 andthe contents of isomenthone, menthone, 10-epi-eudesmol, 6,9-guaiadiene, decanoic acid and isodecanoic acid were relatively lower than in the oils of accessions Bipuli and/or Hemanti. The present study has shown a way for the generation of new genotypes in rose scented geranium in which the cultivars have been vegetatively maintained for decades and the genetic resources are scanty.