33.It is one of nature’s great ironies that the availability ofnitrogen in the soil frequently sets an upper limit on plant growtheven though the plants’ leaves are bathed in a sea of nitrogengas. ; ~8 [! D" L" X3 d, Z- y1 ^下述情形真可谓是自然界的一个莫大讽刺:土壤中所能获得的氮肥量往往对植物的生长构成了一个上限,虽然植物的叶子被沐浴在一片氮气的海洋中。 ) @. E* @0 U# O5 m( M
34.Unless they succeed,the yield gains of the Green Revolutionwill be largely lost even if the genes in legumes that equip thoseplants to enter into a symbiosis with nitrogen fixers are identifiedand isolated,and even if the transfer of those gene complexes,once theyare found,becomes possible. ) Y4 H }" j3 b, q* }9 b 除非他们能取得成功,不然的话,绿色革命的产量收益将在很大程度上损失殆尽,即使豆科植物中使这些植物有条件进入到与固氮细菌共生关系的基因可被辨识出来和分离开来的话,且即使这些基因综合体(gene complex),一旦被发现之后,其移植得以成为可能的话。