Genetic studies of fibre yield-related traits and days to anthesis in some kenaf (Hibiscus cannabinus L.) accessions

摘要

Kenaf (Hibiscus cannabinus L.) is an economically important and multi-purpose natural fibre crop with several industrial applications. However, its potentials have not been fully maximised due to poor yield and its narrow genetic base which limited the available hybrids. The low yield is attributed to high photoperiod sensitivity of most kenaf accessions because it reduces the vegetative growth. This study attempts to understand the genetic architecture of days to anthesis of kenaf towards the development of a photo-insensitive kenaf hybrid. Two early maturing Nigerian kenaf accessions: NHC (12)1 and NHC (3)2, and two late maturing accessions (NHC [9]2 and NHC 15) were crossed to generate F1 population. The F1 hybrid together with its parents and its reciprocals were planted in a randomised complete block experiment design with three replicates. Data were collected on days to anthesis (DTA), plant height (HAH), basal stem girth (GAH), base diameter (BDAH) and weight at harvest (WAH) for analysis. The mean squares were significant for DTA, HAH, DBAH, GAH and WAH. DTA exhibited the highest broad-sense heritability value (0.98) among other traits. The GCA: SCA ratio for DTA and BDAH signifies that the effect of non-additive genes was prevalent because it was lower than a unity while the additive gene action was predominant in HAH. The negative GCA estimates for NHC (12)1 and NHC (9)2 indicated a poor combining ability. Only NHC (3)2 x NHC (9)2 showed good specific combining ability (-5.75, 0.33, 0.85, 91.46) for DTA, GAH, BDAH and WAH respectively. NHC (12)1 x NHC (9)2, NHC (3)2 x NHC (9)2, NHC (3)2 x NHC 15, NHC (9)2 x 3NHC (3)2, NHC (9)2 x NHC 15, NHC 15 x NHC (3)2, NHC 15 x NHC (9)2 showed negative significant percent of F1 heterosis above the mid-parent in days to anthesis and could be employed to breed photo-insensitive early maturing kenaf.