Influence of Hybridization on the Traits of Silk Production and Filament Denier in Indian Tropical Tasar Silk Insect, Antheraea mylitta Drury

摘要

The aim of the present study is to explore hybridization influence to achieve the potential of silk yield and quality in commercial tasarculture, as against the current status of applying only a few wild and semi-domesticated ecoraces of Antheraea mylitta D to produce raw silk during commercial crop rearing season (September-December). The four F-1 hybrid combinations generated using Daba, Jata and Raily tasar ecoraces of seed crop rearing season (July-August) were evaluated during commercial crop season of 2007 and 2008 for the influence of hybridization as positive heterosis in the traits of economically important silk productivity and filament denier. The F-1 hybrid, DabaxJata has recorded positive heterosis in single shell weight (+25.6%), total silk yield (+79.0%) and silk filament length (+68.1%), but for silk filament of high denier (11.98 d) followed by its reciprocal hybrid, JataxDaba in shell weight (+18.8%), silk yield (+68.1%), filament length (+63.8%) and filament of highest denier (12.32 d). Though, the RailyxDaba hybrid could show highest heterosis in shell weight (2.47 g) with filament of least denier (10.86 d), the improvement in filament length was marginal (+44.7%) and heterosis in silk yield was negative (-47.0%), while the performance of DabaxRaily hybrid was least among the hybrids. The study infers hybridization influence on silk related traits at F-1 level as positive heterosis and the application feasibility of DabaxJata and JataxDaba hybrids during commercial crop rearing season for higher silk productivity with silk filament denier at least better than one of the parents of F, hybrid combination.