To mark the start of service between Logan International Airport and Dallas/Fort-Worth International Airport, JetBlue is offering a one-day sale on fares between Boston and any of its daily Texas destinations. The New York carrier, which launched the flights in May, plans to charge one-way fares of $79 for trips between Boston and Dallas/Fort Worth, Austin, or Houston. The price was pegged, in keeping with the Lone Star State theme, to yesterday's closing price of a barrel of oil. Tickets will be on sale through midnight for travel between Sept. 11 and Nov. 14. As part of this promotion, JetBlue also plans to plant one tree for every booking made during this sale. And it will air special content from the TNT cable channel's remake of the old "Dallas'' TV series.