Abstract: The differences of duck varieties may affect the growth characteristics of rice in rice-duck symbiosis system. We selected Youxian partridge duck (SY), Muscovy duck (YY) and mallard (LTY) to explore the effects of different duck varieties on rice growth characteristics, with the conventional rice monoculture as the control (CK). A field plot experiment following randomized block design was used to study the changes of rice root traits, stem traits, leaf traits, and rice yield. The results showed that the YY and LTY treatments had certain negative effects on rice root, stem and leaf traits in the early growth stage of rice (except plant height), resulting in significantly lower growth characteristics compared with the CK. The YY and LTY treatments slowed the aging and decline of root, stem, and leaf, made those traits significantly better than that of CK in the late growth stage of rice, finally increased rice yield by increasing the effective panicles and setting rate. Moreover, the YY and LTY treatments significantly reduced total grain number per panicle, but did not affect the number of filled grains per panicle and thousand-grain weight. Compared with the CK, SY treatment significantly increased leaf dry weight only at full heading stage, and did not affect other agronomic traits at other stages. Our results could provide theoretical basis for the choice of duck varieties in riceduck symbiosis system.

Key words: rice-duck symbiosis, duck variety, rice, root, stem and leaf, yield.