Natural crossing and isolation distance between cotton genotypes in turkey

Abstract

The purposes of this study were to determine the percentage of out-crossing, isolation distance and pollinator insect species for cotton (Gossypium hirsutum L.) seed production in the Aydin region in Turkey. The glandless and red-leaf traits in G. hirsutum were used as genetic markers. Two experiments were conducted over two years that monitored out-crossing in adjacent rows and adjacent plants and established that the percentage of out-crossing varied. The percentage of out-crossing varied between 0% and 13.3% depending on the genetic marker. In the experiment to determine isolation distance, natural crossing percentage was not observed in 2002, while this percentage was 0.8% in the first rows in 2003. In this study, cotton fields were also visited once a week during flowering periods for seven weeks in order to determine the numbers of pollinator insect species, where the only detected species was the honey bee. The numbers of pollinator insects were 2.14% (2002) and 1.30% (2003) for adjacent rows; 1.71% (2002) and 2.00% (2003) for adjacent plants in glandless parcels. It is recommended that the isolation distance between genotypes should be approximately 1 m.