… Recent floods left more than a third of California’s table grapes rotting on the vine. Too much sunlight is burning apple crops. Pests that farmers never used to worry about are marching through lettuce fields. Breeding new crops that can thrive under these assaults is a long game. Solutions are likely to come from an array of research fronts that stretch from molecular gene-editing technology to mining the vast global collections of seeds that have been conserved for centuries. … Here’s a quick look at some of the most promising.