职称英语理工类考试考前每日一练(30)

查字典英语网 2016年03月01日

      SaltyRicePlantBoostsHarvests

      Britishscientistsarebreedinganewgenerationofriceplantsthatwillbeabletogrowinsoilcontainingsaltwater. Theirworkmayenableabandonedfarmstobecomeproductiveoncemore.

      TimFlowersandTonyYeo, fromSussexUniversitysSchoolofBiologicalSciences,havespentseveralyearsresearchinghowcrops, suchasrice, couldbemadetogrowinwaterthathasbecomesalty.

      Thepairhaverecentlybegunathree-yearprogramme, fundedbytheBiotechnologyandBiologicalSciencesResearchCouncil, toestablishwhichgenesenablesomeplantstosurvivesaltyconditions. Theaimistobreedthiscapabilityintocrops, startingwithrice.

      Itisestimatedthateachyearmorethan 10mhectaresofagriculturallandarelostbecausesaltgetsintothesoilandstuntsplants. Theproblemiscausedbyseveralfactors. Inthetropics, mangrovesthatcreateswampsandtraditionallyformedbarrierstoseawaterhavebeencutdown. IntheMediterranean, aseriesofdroughtshavecausedthewatertabletodrop, allowingseawatertoseepin. InLatinAmerica, irrigationoftencausesproblemswhenwaterisevaporatedbytheheat, leavingsaltdepositsbehind.

      Excesssaltthenenterstheplantsandpreventsthemfunctioningnormally. Heavyconcentrationsofmineralsintheplantsstopthemdrawingupthewatertheyneedtosurvive.

      返回查字典首页>>

1/3