1. School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, U.K., College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, P.R. China, Bangabandu Sheikh Mujibur Rahman Agricultural University, Gazipur - 1706, Bangladesh, and Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh