Conclusions
In conclusion, our results suggested that modern wheat allocated more resource to reproduction than to vegetative growth. Old Monkhead can fall into a small degree of the tragedy of the commons when confronting with intra-variety root competition, and the occurrence and magnitude of the tragedy of the commons were dependent on resource availability and variety resource-use strategy. Modern 92-46 has shown a conservative strategy related to efficiency in seed production, while old Monkhead has adopted an exploitative resource strategy related to greater individual competitiveness. Based on our findings, we suggest that crop breeding can increase population yield by consciously selecting varieties which reduce individual competitiveness.