为什么玉米、高粱、甘蔗等作物,在相同的栽培条件下,它们的单产总是高于小麦、水稻、甜菜等作物呢?原来,前一类作物在光合作用过程中,CO_2被吸收固定后生成的最初产物是含有四个碳原子的双羧酸即草酰乙酸(OAA);后一类作物 Why corn, sorghum, sugar cane and other crops, under the same cultivation conditions, their yields are always higher than the wheat, rice, sugar beet and other crops it turned out that the former crop during photosynthesis, CO 2 is absorbed and fixed to generate The original product was a dicarboxylic acid containing four carbon atoms, oxaloacetate (OAA); the latter crop