Abstract
Northeast Thailand is a major sugarcane-producing area, accounting for 35% of the country’s total production, but low productivity during its long dry seasons has been a long-standing problem. Tetraploid Erianthus arundinaceus accessions collected in Thailand could potentially improve the drought tolerance and productivity of sugarcane here, but their early heading prevents intergeneric crossing with sugarcane. We previously developed and successfully applied a photoperiodic treatment (PT) in combination with different ratooning times to delay the heading of hexaploid E. arundinaceus in Japan. Thus, we evaluated the effectiveness of applying this method to tetraploid E. arundinaceus in the effort to enable intergeneric crossing with sugarcane. The effects of combining delayed heading by PT with two ratooning times (March and June) on five selected hexaploid E. arundinaceus accessions were evaluated in two years. The PT delayed the first heading dates by 31-35 days in combination with the March ratooning, and more (38-43 days) in combination with the June ratooning, relative to the heading dates of controls, exposed solely to natural light. Flowers obtained following the delays provided fertile pollen during the heading periods of the sugarcane breeding materials. Therefore, combining PT with different ratooning times can enable intergeneric crossing between these tetraploid E. arundinaceus accessions and sugarcane breeding materials heading from late November to early January. This delayed heading technique will expand the possibility of utilizing diverse tetraploid E. arundinaceus accessions for improving sugarcane in Thailand.
