D.P. Lohar and W.E. Peat
Department of Biological Sciences, Wye College, Wye, Ashford, Kent, TN25 5AH, U.K.

DOI

ABSTRACT

Experiments were carried out to investigate the response of heat sensitive ( Pusa Ruby ) and heat
tolerant (CL-1131) tomato varieties to four different temperature regimes to identify floral
characteristics affected by high temperatures. There was an earlier anthesis in variety CL-1131 than in
Pusa Ruby at 35/30°c (day/night) regime. Flower bud number in the first four trusses and total flower
number at 35/30°c were significantly lower than at normal temperatures (22/17°c) in Pusa Ruby but
these were the same in CL-1131. Stigma exsertion at high temperatures (28/23 and 35/30°c) was the
same in both varieties. Many floral anomalies such as stigma exsertion without anthesis, empty flowers
and persistent flowers without fruit set were also observed at and 35/30°c regime. Antheridial cone
splitting was not observed. The use of stigma exsertion and antheridial cone splitting as criteria for
selecting against fruit set at high temperature may be misleading while selecting for heat tolerance in
tomato.