The influence of root temperature on root-hair infection of Trifolium subterraneum L. by Rhizobium trifolii Dang.

Infection of T. subterraneum root hairs by Rhizobium trifolii was studied at root temperatures of 19°C or 7°C, and at 19°C after 9 days at 7°C. At 19°C infection began on 3-day-old plants but at 7°C was delayed till day 13 and occurred further from the hypocotyl. The initial infection was also slower at 7°C than at 19°C. After nodulation, the infection rate soon slowed at 19°C but not at 7°C. At 19°C, 3 days elapsed between first infection and first nodule formation but only 1 day with plants grown at 7°C or transferred to 19°C after 9 days at 7°C.-R.B. RESP-6368