Effects of CO2 Enrichment at Different Irradiances on Growth and Yield of Wheat: I. EFFECTS OF CULTIVAR AND OF DURATION OF CO2 ENRICHMENT

Wheat, Triticwn aestivum L., the winter cultivars Hobbit andCappelle-Desprez, and the spring cultivars Sicco and KJeiber,were grown in normal air or air enriched with CO₂ either outdoorsin a glass-roofed cage or in controlled environment rooms. Inneither the winter nor the spring wheat was growth increaseddue to enrichment with CO₂ before anthesis. Enrichment of thetwo winter wheat cultivars increased shoot dry weight significantlyat 15 d after anthesis but produced no significant increasein grain yield. With the spring cultivars there was a significantincrease in shoot dry weight by 18 d after anthesis and thegrain yield was also larger due to an increase in grain size.Shoot weight increased because the stems were larger, and therewas a diversion of assimilate from grain growth to late tillerproduction. Root tissue comprised less than 20% of the totaldry matter at anthesis (for all cultivars); effects of CO₂ enrichmenton root growth appeared to be less important than effects onshoot and ear growth. Growth and yield responses to CO₂ enrichmentwere observed (for the spring cultivars) at irradiances of both250 and 635 µE m^–2 s^–1, but the effects weregreater at the lower irradiance. Key words: CO₂ enrichment, Wheat, Cultivar     

二氧化硫熏气对小麦叶片中1-氨基环丙烷-1-羧酸、1-(丙二酰氨基)环丙烷-1-羧酸含量的影响及与乙烯产生的关系

在SO_2熏气9h过程中,小麦叶片中乙烯先上升,约6h达高峰,后下降;ACC含量则随熏气时间的延长而上升。停止熏气,乙烯继续下降,ACC含量也明显降低。MACC含量从熏气3h后不断上升,脱离接触后仍继续增加。6-BA预处理对SO_2引起的乙烯和ACC上升有促进作用,但对MACC含量无明显影响。SO_2熏气提高了乙烯形成酶活性。6-BA预处理对SO_2伤害有保护作用。对逆境乙烯的产生与调节作用进行了讨论。