Evaluation of Quantitative and Qualitative Traits of Different Lettuce Types for Production in Greenhouse Condition

In this study, lettuce cultivars and genotypes native to the country, including two domestic cultivars and six domestic genotypes along with five iceberg lettuce genotypes were evaluated for production in greenhouse conditions. Evaluation was performed in the research greenhouse of the Horticultural Sciences Research Institute in Karaj. The greenhouse experiment was carried out in a randomized complete block design with three replications in spring of 2018. In this study different indices including, number of leaves, leaf length and width, head length and diameter, depth of incisions leaf, , head firmness and yield and qualitative indices like leaf color, texture tenderness, the presence of anthocyanin and maturity were measured. Data were analysed with SPSS ver.16, means comparison was done with Duncan test. Correlation of quantitative traits with yield was done by person test and regression of independent variables with yield was done by linear stepwise method. Results showed a significant positive correlation between the yield and variables including head length and diameter, leaf length and width, leaf numbers. So that, Grizzly cultivar and Borazjan accession with the most head and leaves’ length and diameter had the highest yield in the experiment. Linear regression of the traits with yield revealed that only head’s length had the significant effect on the yield. There were variations in quantitative traits and maturity between accessions and cultivars. The cultivars Bombola, Grizzly, Borazjan, Peache-Ahvaz and Varesh had the good marketable, taste and flavour. Altogether, the superior accessions and cultivars such as Bombola, Grizzly, Borazjan, Peache-Ahvaz and Varesh for using in breeding program or cultivation under greenhouse condition were selected.