The effects of cold and heat pretreatments on floral buds as well as on cultured anthers were examined in 4 tomato lines and their 6 hybrids in three different culture media. Temperature pretreatments included cold (4oC for 48h and 10oC for 10 days), heat (35oC for 4 d) and a combination of cold and heat pretreatments (4oC for 48h followed by 35oC for 4d and 35oC for 4 d, followed by 4oC for 48h). The control and pretreated cultures were Kept at 26oC throughout the experiments. Experimental design was based on a factorial arrangement of completely randomized design. Callus induction (CI), callus diameter (CD) and shoot induction (SI) were recorded. CI was not influenced by pretreatments on floral buds except for 4oC. However all pretreatments of anthers showed CI except for 35oC followed by 4oC. Statistical analyses in the affected pretreatments were carried out. The results indicated that pretreatment, genotype, culture media as well as interaction among them had significant (p<0.01) effects on CI, CD and SI. In anthers pretreated at 4oC followed by 35oC and control, SI was not observed. However, SI was seen in all the other pretreatments. The effects of pretreatment were different among genotypes and culture media. The hybrids Micro-Tina x Moneymaker and Micro-Tina x MSK8 exhibited the highest SI (22- 35.5 %) in all 3 culture media when their floral buds and cultured anthers pretreated at 4oC. However, SI for these hybrids was 14.5% and 18.9% at 10oC, 14.5% and 16.7% at 35oC respectively. Among the parents, SI for MSK8 at 4oC and Micro-Gemma at 35oC of a were more considerable SI (18.9% and 17.8% respectively). It can be deduced that application of cold and heat pretreatment of tomato anther culture will be helpful in production of haploid/doubled haploid population
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