光周期与氮肥互作对华农1号青饲玉米碳氮代谢相关酶的影响

于2005年3-7月,采用盆栽试验,设置3个不同光照长度处理和氮素水平,研究了不同光照时数及氮素水平对远缘玉米杂交种华农1号青饲玉米碳氮代谢相关酶活性的影响.结果表明,在苗期,16 h光照处理下植株叶片磷酸烯醇式丙酮酸羧化酶、蔗糖磷酸合成酶、蔗糖合成酶、谷氨酰胺合成酶和硝酸还原酶等酶的活性显著低于13和10 h光照处理;至抽雄期和收获期,13和10 h处理下植株叶片各种酶的活性下降速率较快,而16 h处理下酶活性下降缓慢且显著高于13和10 h处理.在抽雄期或收获期,16 h处理下叶片各种酶的活性均随施氮量的增加而增加,但在13和10 h处理下均有几种酶的活性在高氮素水平下出现下降的趋势.总的看来,在16 h光照处理下,植株苗期碳氮代谢相对较弱,到中后期代谢能力明显提高,且耐高氮能力也较强,收获期植株叶片酶的活性显著高于13和10 h处理.

Effects of interaction of photoperiod and nitrogen on activities of enzymes of carbon and nitrogen metabolism of Huanong No. 1 ensilage corn

The effects of three lighting durations and three nitrogen levels to distant hybrid Huanong No.1 ensilage corn in a pot experiment from March to July 2005 were investigated.At the seedling stage,the enzymes activities of phosphoenolpyruvate carboxylase(PEPCase),sucrose phosphate synthase(SPS),sucrose synthase(SS),glutamine synthetase(GS) and nitrate reductase(NR) in the 16 h lighting duration treatment were significantly lower than those at 13 and 10 h.At the heading and harvest stages,activities of enzymes reduced rapidly under 13 and 10 h of lighting.In 16 h of light,activities of enzymes declined slowly and but were obviously higher than those in the 13 and 10 h treatments.At the heading and harvest stages,activities of enzymes in the 16 h treatment increased gradually as the nitrogen level was increased,but enzyme activities in the 13 and 10 h treatments began to reduce at high nitrogen levels.In general,the activity of carbon and nitrogen metabolism at 16 h of lighting was relatively low at the seedling stage.At the heading and harvest stages,the activity of carbon and nitrogen metabolism in the 16 h lighting treatment obviously increased and the ability to tolerate high nitrogen levels was stronger.At the harvest stage,the activities of enzymes in the 16 h lighting treatment were significantly higher than those in the 13 h and 10 h treatments.