GERMINATION, EMERGENCE AND GROWTH OF GLYPHOSATE-RESISTANT AND SUSCEPTIBLE BIOTYPES OF GOOSEGRASS (ELEUSINE INDICA)

摘要

The effects of environmental factors on germination, seedling emergence and growth of glyphosate-resistant (R) and -susceptible (S) Eleusine indica (L.) Gaertn. biotypes was conducted under laboratory and greenhouse conditions. The R biotype exhibited greater percentage of germination than that of the S biotype at either constant temperatures of 20, 25, 30, or 35°C under darkness or alternating temperatures of 30/25 or 25/35°C with 12 hours photoperiod. The optimal temperature for germination in both biotypes was found to be at alternating temperatures of 30/20°C or 35/20°C with 12 hours photoperiod. There was no significant difference between the R and S biotypes at these temperature regimes. Maximum emergence occurred when seeds were planted at soil surface but no seedlings emerged at 10 cm depth. The percentage of emergence was greater in the R biotype relative to the S biotype at the depth of 0 and 2 cm. The S biotype produced higher total biomass, shoot, root and number of tillers compared to that of the R biotype under noncompetitive conditions in the greenhouse. However, the R biotype exhibited more reproductive biomass and matured earlier compared to the R biotype. Under water stress conditions, the S biotype partitioned less dry matter to the inflorescence and increased more partitioning into roots compared to the R biotype. Under low light conditions (80% shade), the S biotype reduced more biomass partitioning to the inflorescence and increased more partitioning into vegetative structures relative to the R biotype.