Differential adult lifespan and starvation stress responses in laboratory evolved bivoltine silkworm breeds of Bombyx mori l.

Abstract

Silkworm breeding is majorly focused on balancing the progress of productive trait to generate profitability.However, with recurrent commercialization and utilization of such productive trait through heterosis may decline with drastic climatic variations. In order to achieve and generate profitability in sericulture, paradigm shift is essential through transition from balanced breeding to sustainable breeding via selection of breeding lines with better adult moth longevity which confers the benefits by coping with stressful environment. In the present investigation, CSR bivoltine silkworm breeds were screened to understand the adult moth longevity among them which have attained two decades of evolution. Differential longevity was recorded among the selected breeds. The maximum and minimum longevity was observed in CSR 51 and CSR17 respectively than other breeds. The short-listed breeds were exposed to starvation stress, wherein, interestingly, the CSR51 was highly tolerant compared to other breeds and CSR17 being short-lived was susceptible to starvation stress. The data obtained suggest that the relatively longer lifespan may be rendering more tolerance towards the starvation stress mediated lethality, as evident by the induced starvation stress assay. This would help us to focus on the generation of long-lived breeding lines with better longevity which could intrinsically determine for better abiotic and biotic stress tolerance.